I owned three Yamahas in the 70s with this pump and I never really knew how they worked. They never needed any maintenance and they always worked. Thanks for the explanation.
Perfect timing and perfect video. Just got a 250 and the pump was corroded and frozen. Took it apart and lost my pictures I took. This is a great video. Thanks!
This is one of the very best explanations of a procedure I have ever seen. First time, and already understand the whole system and how to test and tweak. Thanks for sharing your wisdom, the World needs more people like you for sure !!!
Great explanation much easier to understand than the written word in the manuals helped me set my dt 125 up properly so engine safe from oil starvation
I have this exact same bike in the same color, I got it after sifting for 15 years so I cleaned the fuel tank, carb and filled the oil tank with new two stroke oil but didn’t know about the autolube system so this video truly saved me from ruining my original 1974 engine!
This is an outstanding explanation of an auto lube pump. Very, very smooth presentation skills. Spot on! Please continue to put out wonderful videos like this. You are an expert when it comes to explanation and presenting the topic in a simplified manner. Keep up the good work!
This is the best video that i've watched so far on the Autolube!! Here in India, the pump is very underrated because of the "failure" stories. But i am using this on my Yamaha RX100 and its completely failproof!
@@hermetheuscoffee I own a RX135 and the oil pump is flowing oil even when the throttle is fully closed. I have even removed the cable and the story remains the same. I suspect the engine vibes or rather the gravity of the flow is just pushing the oil in which should not be the case, as oil pump is designed to pump oil only when the throttle is opened, im not sure how rpm affects the pump mechanism though. Well, in my case the bike is smoking way too much. How can i fix this problem? Is it something to do with the two seals inside the pump or is it a much bigger problem that im staring at.
@@ragavvijayadev8900 Based on your questions/observations, you might want to re-watch the video again. I cover the operation of the pump and how BOTH throttle position and RPM affect the output of pumped oil. Even with the throttle 100% closed, the pump should pump oil. (I reference this in the video as a way to potentially save your engine if you chop the throttle at high RPM on a downhill.) I would also verify that your adjuster plate (aka the pump pulley in Yamaha terms) is correctly adjusted at 0% throttle. Perhaps your adjuster plate is adjusted too far at 0% throttle and it's pumping in too much oil at idle. Based on the limited clues, this would be my first hunch. But feel free to report back with more findings, clues, and details and I'll try to help out. Good luck!
Jason , I was worried about my auto lube on my ct1 , I am very confident I can service it now. Great video guy . Need to check out a service manual to make sure I got things right.
This is the best explanation i found about how these lovely pumps work. I´m rebuilding a GT80mx with some performance mods but want to have the autolube running, so i was needing some deeper insight on its functionality in order to understand what i had to do to it, so it catchs up with the bigger carb. And this is perfect, posting and running right away to the shop to apply the learnings!
So glad you found it helpful and took the time to write the kind words. Good luck on the GT80 project! I keep a GT80 gas tank on my shelves as a decorative piece... they're cool little bikes!
@@hermetheuscoffee Indeed! After taking some measurements and doing some research, I have carefully filed the so named adjustment pulley to increase the stroke distance, and did the same to the shaft "lifter". The idea is that within the tolerances, it travels a longer distance and pumps more oil when the gas position is beyond the original carb´s curtain. Not sure if that makes sense in words, but I was enlightened by your explanation. Will share the results when i do the caudal test.
@@gambini_modding I love hearing this! Your description makes sense to me, and it confirms that you not only understand how to adjust the pump per procedure, but also WHY you're doing the things you do! Once you understand how these pumps work, they're less mysterious and fear-inducing. Good work!
@@hermetheuscoffee Thanks man! I come with an update: the modifications did not cause any effect sadly. It seems that despite how much you increase the stroke lenght, there´s a maximul fillrate that the pump can do. I measured both ways and in both cases the readings are on spot with the manual specs (which is a sign of good functioning too) but not enough for the bigger carb, i guess. Luckily i have spare pieces and kept the best ones original to revert the change.
@@hermetheuscoffee and btw, if you happen to have somewhere the output rate of models like the dt100, rx100 or any model inbetween, it would be a good guideline. I currently have the gt 80´s original, which is 4.28 per 200 strokes, and yours which is a very large engine to compare with.
Excellent explanation!! Just purchased a '77 dt250 off my buddy and before he got it, fella cut the cable running to the pump and since, the bikes been running premix... I am very interested in getting this system back up and running!! Once again, thanks for the clarification and detail!!
Thank you! As you’ve now seen from the video, simply cutting the cable doesn’t completely shut off oil flow from the pump. It’ll still pump at “idle” ratios. The 1-into-2 cable isn’t cheap, but it’s worth finding to get your bike back to the way Yamaha intended it. Good luck!
I have rebuilt several of these pumps and as it is, stand-alone, they hardly ever fail. Whenever I have had issues it is usually related to the supply line being incorrect (too flexible, collapsing compounded by heat) or maybe the oil seal behind the starter plate leaking. Once I had an adjustment plate return spring break (corrosion) but the bike wasn't running when discovered. FYI Tygon is not a good choice for these pump when selecting supply line from pump to intake. However, it's not bad when going from tank to pump. Thanks for the vid.
What a great video mate! I must admit, I was leaning toward premixing my 74 DT100 as I believe the auto lube pump is giving me issues currently, the carb is perfect yet at WOT it’s giving me lots of smoke and bogging down, I think it’s too rich due to too much oil. After watching your epic video, I’m definitely going to pull my pump apart and get it set right. Thanks for the great video!
Glad you found it helpful! From my experience, the DTs will smoke at WOT + low RPM even when properly tuned. It's pumping a lot of oil in at WOT, and if you're lugging the engine, it has a difficult time burning off all that oil. Pop it a gear lower and let it rev, if possible. If you've got a load on the motor (like going up hill or level ground), you will NOT over-rev it. Happy riding!
Thank you for such an invaluable video! You put my autolube worries away. I just picked up a DT200 a couple weeks back and was really on the fence about installing an autolube pump I just picked up and rebuilt. You explained it perfectly and showed exactly why it's best to check your output prior to running a newly installed/rebuilt pump.
Thanks for taking the time to say that, Daniel. I'm glad it was helpful and clear! I don't think we ever got the DT200 here in the US, but I'm sure it's like any other Yamaha 2-stroke enduro... reliable, powerful, and fun!
Great video, so many people asked me to use premix rather than relying on an oil pump. They should watch this video. Thank you for taking the time and effort to make such an insightful video.
Great video. Also, I have a 75 dt100 that Blew up ( top end) earlier this summer. I rebuilt it but now it has now spark, and the cable that controls the auto line slips off its little pulley when the throttle is opened more than 1/4. It also doesn’t return to its normal idle position quickly- its sticking. Would you have any advice on what to do? I also pulled the flywheel cover off to try and look at the magneto/ points, but I don’t have a puller to take it off. It has a new spark plug/ spark plug cable. Thanks
Thanks, Tyler! Regarding the cable coming off the pulley, you’ve touched on something I completely overlooked in this video! On the pulley, there is a small “protrusion” with a tiny hole in it. You MUST have a pin in this hole to keep the cable from coming out of the pulley! You can use a tiny cotter pin, a small paper clip, or small safety wire… as long as it doesn’t catch on the pump itself, you’ll be good. Regarding not returning to the idle position, are you referring to the pulley on the oil pump? This could be a few things. I would first unhook the throttle cable from the pulley… Does the pulley “snap” back to idle on its own? If so, you just have too much drag in your throttle cable somewhere. (A kink, at the Y junction, or just dry). But if it doesn’t snap back on its own, then you might have a spring that has popped out of the pulley (or has broken). Narrow the problem to either the spring or the cable and then take the next steps from there. Good luck!👍🏻
Just what I nèeded, I got a dt200 I'm servicing before its first ride and it had premix in the tank which makes me wonder. The oil pump is still intact and appears operational. Now I can find out for sure and get it set prolerly!
Thank you for the great video! Do you know what the purpose of the adjustment plate on the pump is (other than getting in the way of me being able to see the roll pin lol)?
Are you referring to the silver plate with the hole in it? This is supposed to be aligned so that you can see the pin through the hole. The purpose of it is to actually HELP you find the pin and the dot that it’s pointing to. Maybe your plate is rotated out of position?
@@hermetheuscoffee Yes, actually have it so that the hole is lined up with the pin pretty closely. But my plate is unlike this one in that it almost completely covers the area where the pin is unless you're looking through the hole. When you're tightening down the nut it's hard to keep it perfectly in line as it wants to move. It's very easy for me to line up the pin without the plate in the way. I'm just wondering if there's another purpose for the plate or if I can just take it off and it will be okay. Thanks!
Thanks very much for making this video, Jason. I came across your video for timing the DT250 as well and it was also a great help. I picked up a '75 DT250-B about a month ago and have been diagnosing/repairing issues since then. Much of my work was related to the wiring, which I have about 95% sorted out now. Today though, I noticed what appeared to be bubbles near the top of the oil injection line right where it enters the carburetor (that's where mine feeds oil into the engine). At idle, it even appeared to me like the oil in the line would "bleed down" toward the pump a bit, and it would take about 20 seconds of revving to a higher RPM to get the line full back up to the carb. I think you mentioned that there was a check valve in the pump to prevent this bleed down, correct? It may be just my imagination too, but it actually looked like the oil near the top of the line where the bubbles were was very "thin"...and I'm wondering if some of the atomized fuel mixture was flowing back into the line from the carb! Is this even possible? I'm going to do the complete pump bleeding process to be safe, as I did in fact have to put a new line on from the pump to the carb a few weeks back. At the time though, we saw the oil climb up the line all the way to the carb after revving the bike for only about 60 seconds. And yes...I did have pre-mix in the tank just in case.
Hey, Spudman, glad you've found the videos helpful! What you describe certainly sounds possible, and the check valve is the first thing I would investigate. Thankfully, it's SUPER easy to get to. The brass outlet port on your pump, where you have a hose that runs to your carb, is just a press-fit port. You can firmly grab it with pliers and twist it off (be sure not to put torque on the barbed nipple part, though, because it can break off). Just put torque on the main brass barrel part. As soon as you get it off, be careful because there's a spring and a 5/32" ball in there and you don't want to lose either. The spring presses the ball against a rubber seal. Just give that all a really good inspection. You might just have some sludge buildup that's preventing the ball from properly seating. You might have a missing or weak spring. You might have a missing or damaged rubber seal. You might have a corroded check valve ball (unlikely, but not impossible). But the bottom line is that if the ball doesn't seal properly, you'll get the EXACT symptoms you describe. The oil will very slowly drain back into the pump (by gravity), and yes, your fuel mixture can 100% go into that same port to "thin" out the oil a bit. That port on the carb is just a straight shot into the main intake, so it's also a straight shot back down the oil line if you're draining oil back into the pump. That's really the only culprit that I can imagine. If that check valve is doing its job, there's no way way for that air bubble to form at the top of the oil line. So HOPEFULLY all you need is a good cleaning and reassembly and you'll be good to go. Good luck!
@@hermetheuscoffee ....thank you very much for the DIY check valve repair info! I'll have a look at the check valve ball, spring and seal and see what I find and let you know. I'm in the process of replacing tubes, tires and brakes now, but the autolube pump will be next on the agenda.
@@spudman1125R sounds like you’re checking all the right boxes on bringing this back to life! If you haven’t done so, I would HIGHLY recommend doing a leak down test. The crank seals tend to dry/crack, and if you’re pulling air in, you have a lean condition that’ll seize an engine quickly!
@@hermetheuscoffee ...thanks for the tip. I have a good friend helping me that owns his own shop and has been a bike mechanic for 40+ years. His knowledge has helped me so much already, and I'll be calling on that knowledge again tomorrow. The 2 Phillips screws holding the pump to the engine case are almost completely destroyed. That's how I found them today. My buddy says not to worry...that we'll get them out...and I hope he's right once again. They wouldn't even budge rapping them with an impact driver...the heads are nothing but round divots.So repairing that check valve will need to wait until we can get the pump removed, as I don't think we can get that outlet nipple removed and reinstalled while the pump is still mounted. I'll keep you posted though! Thanks!
Well, after about an hour of tedious work with a metal chisel on Saturday, my buddy was able to get the destroyed screws to turn and we got them out. Took the pump inlet nipple off and removed the spring and ball and found a somewhat corroded and pitted ball, which we replaced. Reinstalled the pump with Allen screws and started the bike and there is no longer any bleed down of the oil back into the pump! Thanks again for your help and advice Jason!
thanks a lot. i'm almost done with my restoration and i didn't know how to check the autolube system. DO YOU HAVE A VIDEO SHOWING THE SHIMMING PROCESS? thanks
I don't have a video of that, but it really is as simple as taking the nut off and adding/removing shims as necessary. In my experience, this is rarely needed, unless that machined "ramp" has become worn due to a TON of use. Good luck!
Hi Jason, congratiulation. Realy a great video. At the moment I restore a YAMAHA DT 250 (Typ 512) here in Germany. I bought the bike some years ago and collected a lot of (mostly NOS) part. Also the Autolube oil pump. The pump was in a org. YAMAHA box with the right part number. But inside the was a (NOS) Autolube pump without the outer plastic wheel. Maybe it is a pump for the 77-MX-model?! Do you know if it is possible to run the 75-DT with the 77-MX pump? Best regards from Germany Knuth
Hi Jason, Great video of exactly what I am going through now! I have a question if I may ask. What is the purpose of that odd shaped "washer" right under the nut and lockwasher just above the adjustment plate? I have it on my DT360 as you do on your DT250, but it seems to serve no purpose. Or am I wrong? Other Yamaha models do not have this plate! Thx again!!
I'm not 100% sure on this, but I'm PRETTY sure that plate is nothing more than a circular "window" to draw your eye to the pin that you align with the dot. When the pump is installed on the bike, it can be a bit harder to even find the pin, so this little washer-like plate you talk about helps orient you. You look through the round hole and the pin should be right there in the middle of it. It's not functionally necessary, so if you're lacking that, don't worry about it! Yamaha also did away with the white priming wheel (the one that I spin with the cordless screwdriver) on the "new style" autolube pumps, so if you're missing that as well, don't worry about it! Good luck, and happy riding.
@@hermetheuscoffee Thank you again! You have no idea how much this video has helped me. I had to make my own shims to get the gap correct as the previous owner screwed it all up and there was no movement of the pump at idle (that silly washer thing was mounted UNDER the large washer not above it and no shims in sight). But as of 15 minutes ago I have perfect gaps at idle and FT.
Absolutely! Anything the turns the engine over will spin the pump. You could add some premix gas to the tank and run it for a while to make sure it's fully in the carb/engine, then unhook the oil line and let it idle. At idle speed with your finger on the head of the pump (the part the moves in and out), you can very easily feel it and count the strokes.
If you're referring to the wheel to prime the pump, then no, the bike doesn't have to be in neutral. Yamaha wisely engineered a slipper clutch into the oil pump assembly, so you can spin that white priming wheel in gear OR in neutral. It makes no difference.
Lost compression. My fault. Havnt pulled the head. What's your opinion on top end rebuilding? Are the jugs sleeved? Who sells a decent piston and ring set, ect? Thanks.
It's super easy. The cylinder isn't sleeved. Start by pulling the cylinder to find out the extent of your damage. For instance, you MIGHT just have a hole in the top of your piston, but no cylinder wall damage. But find out how extensive the damage is, then I would suggest posting a picture to yamaha-enduros.com. There's a wealth of Yamaha DT knowledge on that site! You can still find original Yamaha pistons pretty easily for these bikes. But before you order, you'll want to pull the cylinder to make sure you don't need to bore it out first. If you have to bore it, figure out how much is required (1 over, 2 over, etc.) then order the right piston for how far it's been bored.
Where did you find the specs for the "200 pump output" or is it the same for all oldish dt's. i have a dt50mx that i've recently rebuilt the pump on and i would like to test it just to make sure.
For the DT250, the quantity @ strokes was in the service manual. For the DT50MX, however, that metric isn't provided. Just aligning the pin with the stamped dot.
Great video! Very informative. I just recently picked up a Yamaha AT3. I don't recall if I heard this in the video. Would it be harmful if I filled the tank with 50:1 premix with the autolube functioning properly? I will be winterizing it soon. Just wondering if that fuel would be okay.
It's not going to be harmful, but what would be the point of doing it? Adding 50:1 premix as a winterizing step probably isn't as good as using ethanol-free gasoline with StaBil in it. Or better yet, draining the tank and carb dry.
@@hermetheuscoffee thank you for your reply. The question was out of pure laziness. I have a new can of 50:1. Just seeing if I could save a trip to the store. I will drain the tank instead.
Just purchased a rough 74 dt250 with the hopes of giving it a better life than the previous owner. The autolube oil reservoir is missing and he said he just pre-mixed the fuel. Can anybody tell me the proper oil mix ratio? I doubt I'll be able to source the parts to revert back to autolube
good info on this system i recently picked up for free 2 matching 1972 dt250 enduro bikes one in mint condition 1 a mid level condition have been sitting for 20 years in the mts in colorado ..0 rust . started doing a full restoration on the mint one and will certainly go thru your video's Thank you
Thank you for such a thorough video on these pumps. I have recently rebuilt my pump, and bled the air. Going thru the preliminary oil output tests, I am not getting much (if any) oil at idle. However , if I apply slight pressure to the pump end (where we count the strokes), it will pump noticeably more. Am I missing something here? Cable adjustment? I appreciate all the great info shared here!!
The first thing that comes to mind is resistance in the main pump shaft. Remember that the pump shaft is being pushed outward MECHANICALLY, then pulled inward (e.g. pressing down on the pump head) BY A SPRING. if there is resistance in getting smooth pump strokes (or a weak spring), then it won't fully push the pump downward and you'll get exactly what you describe. However, the tolerances at idle are so small, you might also just have a slight adjustment of the cable needed. That is, if you aligned your pin to the dot, the pump pulley will start to move downward to increase the pump stroke (oil output). If there is some play in your pump pulley, then pushing it in by hand more aggressively might just be physically moving the pump pulley. I would take a look at 13:40 in the video. At full throttle (bike not running) can you physically push the pump outward like I'm doing, then see it fully and smoothly retract in? If this motion is very smooth and has no "tight spots" or resistance, then you're still probably just looking at an adjustment that is needed somewhere. If you feel resistance anywhere at all, then you have a different issue. The one thing that I'm curious about is your process of "rebuilding". These typically aren't rebuilt/serviceable (unless you really know what you're doing). What did your rebuild consist of?
Thanks so much for your reply. I just checked the pump and at full throttle, it does pull out and retract with no issue. This morning, as I spun the starter 'gear', it appeared to be moving more oil than what I noticed yesterday. I dont have access to be able to use a drill (as you did in the video) so perhaps I've not spun it up enough at idle to produce enough oil to be noticeable. Also, in response to your questions, yes the stop pin is aligned with the dot. Also, I purchased a gasket and seal kit and disassembled and installed those new components in the pump. (Maybe not necessarily a 'rebuild'). At full throttle, it definitely moves oil!
@@matstang1491 It sounds to me that your pump is probably good to go. The quantity of oil pumped at idle is VERY small. At 33:30 in the video, I've actually sped the video up significantly. If you're spinning it by hand, it might not LOOK like anything is pumping unless you do it for a long time. In addition, although you bled the pump, the line going from the pump to the cylinder could have also had air in it... so until you've purged THAT air, your readings could also be off. If the pump moves freely, quantities look good at full throttle and you're getting SOMETHING at idle, odds are in your favor that you're in the ballpark.
Great news. I have been hesitant to start the bike after the rebuild but feeling confident now. Best video on youtube on these pumps. And thank you, thank you for taking time to help me out!
@@hermetheuscoffee I have a similar issue. At idle, nothing. When I tighten the nut down, it doesn't allow the shaft to move up and down when I turn the wheel. When the nut is loose, it can move up and down. Is that normal?
They are not even remotely similar. The pump in this video is an oil INJECTION pump for a 2 stroke engine. It's pumping oil into the crankcase that will then be burned in the combustion cycles. It's nothing like a 4-stroke oil lubrication pump like the Virago.
Best Part is these pumps are all the same. GLAD THIS MAN CALLED OUT THE PEOPLE WHO THINK THERE PUMP IS a faulty part of the bike it's your fault if you starve your engine
I’m starting to work on a dt 360 that has been sitting for many years. This video is invaluable , thanks for posting
I owned three Yamahas in the 70s with this pump and I never really knew how they worked. They never needed any maintenance and they always worked. Thanks for the explanation.
Have not seen one go out in 50 years. Those pumps will out live us all. Great video
Perfect timing and perfect video. Just got a 250 and the pump was corroded and frozen. Took it apart and lost my pictures I took. This is a great video. Thanks!
This is a pretty old video at this point, so I’m glad it continues to help people! Thanks for the comment, and good luck on the rebuild b
This is one of the very best explanations of a procedure I have ever seen. First time, and already understand the whole system and how to test and tweak. Thanks for sharing your wisdom, the World needs more people like you for sure !!!
Thanks so much, Johnny!
Great explanation much easier to understand than the written word in the manuals helped me set my dt 125 up properly so engine safe from oil starvation
I have this exact same bike in the same color, I got it after sifting for 15 years so I cleaned the fuel tank, carb and filled the oil tank with new two stroke oil but didn’t know about the autolube system so this video truly saved me from ruining my original 1974 engine!
Sweet! I’m glad you found it helpful. Enjoy your amazing machine.
This is an outstanding explanation of an auto lube pump. Very, very smooth presentation skills. Spot on! Please continue to put out wonderful videos like this. You are an expert when it comes to explanation and presenting the topic in a simplified manner. Keep up the good work!
One of the best "How To's" that I've found. Thank you.
Thank you!
This is the best video that i've watched so far on the Autolube!! Here in India, the pump is very underrated because of the "failure" stories. But i am using this on my Yamaha RX100 and its completely failproof!
Thanks, Sanjay! It should give you years of reliable operation.
@@hermetheuscoffee I own a RX135 and the oil pump is flowing oil even when the throttle is fully closed. I have even removed the cable and the story remains the same. I suspect the engine vibes or rather the gravity of the flow is just pushing the oil in which should not be the case, as oil pump is designed to pump oil only when the throttle is opened, im not sure how rpm affects the pump mechanism though. Well, in my case the bike is smoking way too much. How can i fix this problem? Is it something to do with the two seals inside the pump or is it a much bigger problem that im staring at.
@@ragavvijayadev8900 Based on your questions/observations, you might want to re-watch the video again. I cover the operation of the pump and how BOTH throttle position and RPM affect the output of pumped oil. Even with the throttle 100% closed, the pump should pump oil. (I reference this in the video as a way to potentially save your engine if you chop the throttle at high RPM on a downhill.) I would also verify that your adjuster plate (aka the pump pulley in Yamaha terms) is correctly adjusted at 0% throttle. Perhaps your adjuster plate is adjusted too far at 0% throttle and it's pumping in too much oil at idle. Based on the limited clues, this would be my first hunch. But feel free to report back with more findings, clues, and details and I'll try to help out. Good luck!
Exceptional display of functional expertise. Thank you!
Great video. I have just bought a dt 250 and have been able to check the pump. Thank you
Will also add in with what an excellent video this is.
Thank you for a great detailed explanation!
Really really well made. I was going disable my 75' DT250 autolube and go to premix until I saw this.
Great! No need to ditch it if it’s not broken.
Jason , I was worried about my auto lube on my ct1 , I am very confident I can service it now. Great video guy . Need to check out a service manual to make sure I got things right.
Glad it gave you some confidence, Mike. Thanks for the kind words. Happy riding!
Much appreciated. I'm about to service my 1977 DT 100 and needed this information. You rock.
Thanks, Glenn! Glad it was helpful!
Invaluable info, thank you for taking the time.
My pleasure!
Thanks a lot for this video. I was thinking of retrofitting Autolube from a scooter onto a 63cc 2 stroke generator just for learning purposes.
This video is best on yt about this
Thanks!
This is the best explanation i found about how these lovely pumps work. I´m rebuilding a GT80mx with some performance mods but want to have the autolube running, so i was needing some deeper insight on its functionality in order to understand what i had to do to it, so it catchs up with the bigger carb. And this is perfect, posting and running right away to the shop to apply the learnings!
So glad you found it helpful and took the time to write the kind words. Good luck on the GT80 project! I keep a GT80 gas tank on my shelves as a decorative piece... they're cool little bikes!
@@hermetheuscoffee Indeed! After taking some measurements and doing some research, I have carefully filed the so named adjustment pulley to increase the stroke distance, and did the same to the shaft "lifter". The idea is that within the tolerances, it travels a longer distance and pumps more oil when the gas position is beyond the original carb´s curtain. Not sure if that makes sense in words, but I was enlightened by your explanation. Will share the results when i do the caudal test.
@@gambini_modding I love hearing this! Your description makes sense to me, and it confirms that you not only understand how to adjust the pump per procedure, but also WHY you're doing the things you do! Once you understand how these pumps work, they're less mysterious and fear-inducing. Good work!
@@hermetheuscoffee Thanks man! I come with an update: the modifications did not cause any effect sadly. It seems that despite how much you increase the stroke lenght, there´s a maximul fillrate that the pump can do. I measured both ways and in both cases the readings are on spot with the manual specs (which is a sign of good functioning too) but not enough for the bigger carb, i guess. Luckily i have spare pieces and kept the best ones original to revert the change.
@@hermetheuscoffee and btw, if you happen to have somewhere the output rate of models like the dt100, rx100 or any model inbetween, it would be a good guideline. I currently have the gt 80´s original, which is 4.28 per 200 strokes, and yours which is a very large engine to compare with.
Top video mate.
I had no idea where was the pump on the bike even though I had few dt bikes.
Excellent explanation!! Just purchased a '77 dt250 off my buddy and before he got it, fella cut the cable running to the pump and since, the bikes been running premix... I am very interested in getting this system back up and running!! Once again, thanks for the clarification and detail!!
Thank you! As you’ve now seen from the video, simply cutting the cable doesn’t completely shut off oil flow from the pump. It’ll still pump at “idle” ratios. The 1-into-2 cable isn’t cheap, but it’s worth finding to get your bike back to the way Yamaha intended it. Good luck!
This was great. Wish I had TH-cam back in the 70s when I had some autolube issues on my GTMX 80.
I have rebuilt several of these pumps and as it is, stand-alone, they hardly ever fail. Whenever I have had issues it is usually related to the supply line being incorrect (too flexible, collapsing compounded by heat) or maybe the oil seal behind the starter plate leaking. Once I had an adjustment plate return spring break (corrosion) but the bike wasn't running when discovered. FYI Tygon is not a good choice for these pump when selecting supply line from pump to intake. However, it's not bad when going from tank to pump. Thanks for the vid.
What a great video mate! I must admit, I was leaning toward premixing my 74 DT100 as I believe the auto lube pump is giving me issues currently, the carb is perfect yet at WOT it’s giving me lots of smoke and bogging down, I think it’s too rich due to too much oil. After watching your epic video, I’m definitely going to pull my pump apart and get it set right. Thanks for the great video!
Glad you found it helpful! From my experience, the DTs will smoke at WOT + low RPM even when properly tuned. It's pumping a lot of oil in at WOT, and if you're lugging the engine, it has a difficult time burning off all that oil. Pop it a gear lower and let it rev, if possible. If you've got a load on the motor (like going up hill or level ground), you will NOT over-rev it. Happy riding!
Just bought a 1974 ty250 the manual explanation on this was not good. This video saved me.
Sweet! Glad it helped, Rodney. Enjoy the bike!
Thank you for such an invaluable video! You put my autolube worries away. I just picked up a DT200 a couple weeks back and was really on the fence about installing an autolube pump I just picked up and rebuilt. You explained it perfectly and showed exactly why it's best to check your output prior to running a newly installed/rebuilt pump.
Thanks for taking the time to say that, Daniel. I'm glad it was helpful and clear! I don't think we ever got the DT200 here in the US, but I'm sure it's like any other Yamaha 2-stroke enduro... reliable, powerful, and fun!
This is fantastic help. You should do a full rebuild video bc I'm currently reviving a 73 dt250 and am overwhelmed.
I no longer have my DT, but they're still fantastic bikes. Best of luck on the rebuild!
FANTASTIC MANY THANKS
Great video, so many people asked me to use premix rather than relying on an oil pump. They should watch this video. Thank you for taking the time and effort to make such an insightful video.
Thanks for the kind words. Next time someone tells you to ditch the pump, point them to this video!
Excellent work! Thank you so much for this video.
Great video. Also, I have a 75 dt100 that Blew up ( top end) earlier this summer. I rebuilt it but now it has now spark, and the cable that controls the auto line slips off its little pulley when the throttle is opened more than 1/4. It also doesn’t return to its normal idle position quickly- its sticking. Would you have any advice on what to do? I also pulled the flywheel cover off to try and look at the magneto/ points, but I don’t have a puller to take it off. It has a new spark plug/ spark plug cable. Thanks
Thanks, Tyler! Regarding the cable coming off the pulley, you’ve touched on something I completely overlooked in this video! On the pulley, there is a small “protrusion” with a tiny hole in it. You MUST have a pin in this hole to keep the cable from coming out of the pulley! You can use a tiny cotter pin, a small paper clip, or small safety wire… as long as it doesn’t catch on the pump itself, you’ll be good.
Regarding not returning to the idle position, are you referring to the pulley on the oil pump? This could be a few things. I would first unhook the throttle cable from the pulley… Does the pulley “snap” back to idle on its own? If so, you just have too much drag in your throttle cable somewhere. (A kink, at the Y junction, or just dry).
But if it doesn’t snap back on its own, then you might have a spring that has popped out of the pulley (or has broken). Narrow the problem to either the spring or the cable and then take the next steps from there. Good luck!👍🏻
Very well done, thanks!
Just what I nèeded, I got a dt200 I'm servicing before its first ride and it had premix in the tank which makes me wonder. The oil pump is still intact and appears operational. Now I can find out for sure and get it set prolerly!
Glad it helped!
Great video
Thank you
Excellent!! Thank you so much for this epic video. You're great at educating too!
Thanks, William! I actually used to be a teacher. 😉
That was such a great video. Thanks for taking the time.
Thanks for the kind words... glad you enjoyed it!
Thank you. The wording in the manual is tough to follow (especially considering some of the misnomer terms you mentioned here). Much appreciated!
Thanks, Tyler! I’m glad it was helpful.
Great video
Thank you for the great video! Do you know what the purpose of the adjustment plate on the pump is (other than getting in the way of me being able to see the roll pin lol)?
Are you referring to the silver plate with the hole in it? This is supposed to be aligned so that you can see the pin through the hole. The purpose of it is to actually HELP you find the pin and the dot that it’s pointing to. Maybe your plate is rotated out of position?
@@hermetheuscoffee Yes, actually have it so that the hole is lined up with the pin pretty closely. But my plate is unlike this one in that it almost completely covers the area where the pin is unless you're looking through the hole. When you're tightening down the nut it's hard to keep it perfectly in line as it wants to move. It's very easy for me to line up the pin without the plate in the way. I'm just wondering if there's another purpose for the plate or if I can just take it off and it will be okay. Thanks!
@@bb8215 I THINK you’d be okay to remove it. I can’t think of any other functional purpose for it.
Jason, thank you, oil pump demystified!
Really well done. Liked and subscribed.
Where did you get the spec for the oil volume per 200 rotations ? Great video btw !
Thank you! The oil output volumes come directly from the Yamaha DT250A service manual.
Thanks very much for making this video, Jason. I came across your video for timing the DT250 as well and it was also a great help. I picked up a '75 DT250-B about a month ago and have been diagnosing/repairing issues since then. Much of my work was related to the wiring, which I have about 95% sorted out now. Today though, I noticed what appeared to be bubbles near the top of the oil injection line right where it enters the carburetor (that's where mine feeds oil into the engine). At idle, it even appeared to me like the oil in the line would "bleed down" toward the pump a bit, and it would take about 20 seconds of revving to a higher RPM to get the line full back up to the carb. I think you mentioned that there was a check valve in the pump to prevent this bleed down, correct? It may be just my imagination too, but it actually looked like the oil near the top of the line where the bubbles were was very "thin"...and I'm wondering if some of the atomized fuel mixture was flowing back into the line from the carb! Is this even possible? I'm going to do the complete pump bleeding process to be safe, as I did in fact have to put a new line on from the pump to the carb a few weeks back. At the time though, we saw the oil climb up the line all the way to the carb after revving the bike for only about 60 seconds. And yes...I did have pre-mix in the tank just in case.
Hey, Spudman, glad you've found the videos helpful! What you describe certainly sounds possible, and the check valve is the first thing I would investigate. Thankfully, it's SUPER easy to get to. The brass outlet port on your pump, where you have a hose that runs to your carb, is just a press-fit port. You can firmly grab it with pliers and twist it off (be sure not to put torque on the barbed nipple part, though, because it can break off). Just put torque on the main brass barrel part. As soon as you get it off, be careful because there's a spring and a 5/32" ball in there and you don't want to lose either. The spring presses the ball against a rubber seal. Just give that all a really good inspection. You might just have some sludge buildup that's preventing the ball from properly seating. You might have a missing or weak spring. You might have a missing or damaged rubber seal. You might have a corroded check valve ball (unlikely, but not impossible). But the bottom line is that if the ball doesn't seal properly, you'll get the EXACT symptoms you describe. The oil will very slowly drain back into the pump (by gravity), and yes, your fuel mixture can 100% go into that same port to "thin" out the oil a bit. That port on the carb is just a straight shot into the main intake, so it's also a straight shot back down the oil line if you're draining oil back into the pump. That's really the only culprit that I can imagine. If that check valve is doing its job, there's no way way for that air bubble to form at the top of the oil line. So HOPEFULLY all you need is a good cleaning and reassembly and you'll be good to go. Good luck!
@@hermetheuscoffee ....thank you very much for the DIY check valve repair info! I'll have a look at the check valve ball, spring and seal and see what I find and let you know. I'm in the process of replacing tubes, tires and brakes now, but the autolube pump will be next on the agenda.
@@spudman1125R sounds like you’re checking all the right boxes on bringing this back to life! If you haven’t done so, I would HIGHLY recommend doing a leak down test. The crank seals tend to dry/crack, and if you’re pulling air in, you have a lean condition that’ll seize an engine quickly!
@@hermetheuscoffee ...thanks for the tip. I have a good friend helping me that owns his own shop and has been a bike mechanic for 40+ years. His knowledge has helped me so much already, and I'll be calling on that knowledge again tomorrow. The 2 Phillips screws holding the pump to the engine case are almost completely destroyed. That's how I found them today. My buddy says not to worry...that we'll get them out...and I hope he's right once again. They wouldn't even budge rapping them with an impact driver...the heads are nothing but round divots.So repairing that check valve will need to wait until we can get the pump removed, as I don't think we can get that outlet nipple removed and reinstalled while the pump is still mounted. I'll keep you posted though! Thanks!
Well, after about an hour of tedious work with a metal chisel on Saturday, my buddy was able to get the destroyed screws to turn and we got them out. Took the pump inlet nipple off and removed the spring and ball and found a somewhat corroded and pitted ball, which we replaced. Reinstalled the pump with Allen screws and started the bike and there is no longer any bleed down of the oil back into the pump! Thanks again for your help and advice Jason!
thanks a lot. i'm almost done with my restoration and i didn't know how to check the autolube system. DO YOU HAVE A VIDEO SHOWING THE SHIMMING PROCESS? thanks
I don't have a video of that, but it really is as simple as taking the nut off and adding/removing shims as necessary. In my experience, this is rarely needed, unless that machined "ramp" has become worn due to a TON of use. Good luck!
Thank you.
Nice tutorial but didn't hear you say any thing about the shims behind the cable wheel they play a big part in the pump to .
I briefly touch on shims at the 25:00 mark. If there’s something you feel I’ve missed, please add to the comments to help others. Thanks!
How did you get all this knowledge about the pump and the measurements
It’s from the original Yamaha service manual. It has a wealth of detailed information about the bike.
Hi Jason,
congratiulation. Realy a great video.
At the moment I restore a YAMAHA DT 250 (Typ 512) here in Germany. I bought the bike some years ago and collected a lot of (mostly NOS) part. Also the Autolube oil pump. The pump was in a org. YAMAHA box with the right part number. But inside the was a (NOS) Autolube pump without the outer plastic wheel. Maybe it is a pump for the 77-MX-model?!
Do you know if it is possible to run the 75-DT with the 77-MX pump?
Best regards from Germany
Knuth
Hi Jason, Great video of exactly what I am going through now! I have a question if I may ask. What is the purpose of that odd shaped "washer" right under the nut and lockwasher just above the adjustment plate? I have it on my DT360 as you do on your DT250, but it seems to serve no purpose. Or am I wrong? Other Yamaha models do not have this plate! Thx again!!
I'm not 100% sure on this, but I'm PRETTY sure that plate is nothing more than a circular "window" to draw your eye to the pin that you align with the dot. When the pump is installed on the bike, it can be a bit harder to even find the pin, so this little washer-like plate you talk about helps orient you. You look through the round hole and the pin should be right there in the middle of it. It's not functionally necessary, so if you're lacking that, don't worry about it! Yamaha also did away with the white priming wheel (the one that I spin with the cordless screwdriver) on the "new style" autolube pumps, so if you're missing that as well, don't worry about it! Good luck, and happy riding.
@@hermetheuscoffee Thank you again! You have no idea how much this video has helped me. I had to make my own shims to get the gap correct as the previous owner screwed it all up and there was no movement of the pump at idle (that silly washer thing was mounted UNDER the large washer not above it and no shims in sight). But as of 15 minutes ago I have perfect gaps at idle and FT.
@@rolandwheeler7617 oh yikes! Glad you found the video useful and that it helped get things straightened out!
Is there a way to check the output on the later models without the wheel? Great explanation and instruction.
Absolutely! Anything the turns the engine over will spin the pump. You could add some premix gas to the tank and run it for a while to make sure it's fully in the carb/engine, then unhook the oil line and let it idle. At idle speed with your finger on the head of the pump (the part the moves in and out), you can very easily feel it and count the strokes.
Does the bike have to be in neutral to spin the wheel with a drill? I presume damage would occur if the bike was in gear?
If you're referring to the wheel to prime the pump, then no, the bike doesn't have to be in neutral. Yamaha wisely engineered a slipper clutch into the oil pump assembly, so you can spin that white priming wheel in gear OR in neutral. It makes no difference.
what kind of oil do you use?
Great info. Using it to check out the pump on my DT360.
Any chance you have the vid on retiring to 12v?
No, I didn’t create a video for that, but it was fairly straightforward using the instructions from PowerDynamo.
Lost compression. My fault. Havnt pulled the head. What's your opinion on top end rebuilding? Are the jugs sleeved? Who sells a decent piston and ring set, ect? Thanks.
It's super easy. The cylinder isn't sleeved. Start by pulling the cylinder to find out the extent of your damage. For instance, you MIGHT just have a hole in the top of your piston, but no cylinder wall damage. But find out how extensive the damage is, then I would suggest posting a picture to yamaha-enduros.com. There's a wealth of Yamaha DT knowledge on that site! You can still find original Yamaha pistons pretty easily for these bikes. But before you order, you'll want to pull the cylinder to make sure you don't need to bore it out first. If you have to bore it, figure out how much is required (1 over, 2 over, etc.) then order the right piston for how far it's been bored.
Where did you find the specs for the "200 pump output" or is it the same for all oldish dt's. i have a dt50mx that i've recently rebuilt the pump on and i would like to test it just to make sure.
For the DT250, the quantity @ strokes was in the service manual. For the DT50MX, however, that metric isn't provided. Just aligning the pin with the stamped dot.
I will say that it will NOT be the ballpark of what my DT250 needed in this video! The 50cc engine would require much less oil!
@@hermetheuscoffee okay. thanks!
Great video! Very informative. I just recently picked up a Yamaha AT3. I don't recall if I heard this in the video. Would it be harmful if I filled the tank with 50:1 premix with the autolube functioning properly? I will be winterizing it soon. Just wondering if that fuel would be okay.
It's not going to be harmful, but what would be the point of doing it? Adding 50:1 premix as a winterizing step probably isn't as good as using ethanol-free gasoline with StaBil in it. Or better yet, draining the tank and carb dry.
@@hermetheuscoffee thank you for your reply. The question was out of pure laziness. I have a new can of 50:1. Just seeing if I could save a trip to the store. I will drain the tank instead.
@@LastmanLaPan oh, you’re good! Ride and have fun smelling the extra smoke. 😀
Just purchased a rough 74 dt250 with the hopes of giving it a better life than the previous owner. The autolube oil reservoir is missing and he said he just pre-mixed the fuel. Can anybody tell me the proper oil mix ratio? I doubt I'll be able to source the parts to revert back to autolube
32:1 ratio. Have fun with it!
good info on this system i recently picked up for free 2 matching 1972 dt250 enduro bikes one in mint condition 1 a mid level condition have been sitting for 20 years in the mts in colorado ..0 rust . started doing a full restoration on the mint one and will certainly go thru your video's Thank you
That sounds like an amazing find! Good luck getting them back to the streets.
I wonder if my Yamaha Enduro Jt2 60 has a similar pump model to this. Anyone know if it’s similar? ml amount will be different?
Yes, it's the same pump design, but the tolerances/output values will be different. But the overall pump design and operation is identical.
Thank you for such a thorough video on these pumps. I have recently rebuilt my pump, and bled the air. Going thru the preliminary oil output tests, I am not getting much (if any) oil at idle. However , if I apply slight pressure to the pump end (where we count the strokes), it will pump noticeably more. Am I missing something here? Cable adjustment? I appreciate all the great info shared here!!
The first thing that comes to mind is resistance in the main pump shaft. Remember that the pump shaft is being pushed outward MECHANICALLY, then pulled inward (e.g. pressing down on the pump head) BY A SPRING. if there is resistance in getting smooth pump strokes (or a weak spring), then it won't fully push the pump downward and you'll get exactly what you describe. However, the tolerances at idle are so small, you might also just have a slight adjustment of the cable needed. That is, if you aligned your pin to the dot, the pump pulley will start to move downward to increase the pump stroke (oil output). If there is some play in your pump pulley, then pushing it in by hand more aggressively might just be physically moving the pump pulley.
I would take a look at 13:40 in the video.
At full throttle (bike not running) can you physically push the pump outward like I'm doing, then see it fully and smoothly retract in? If this motion is very smooth and has no "tight spots" or resistance, then you're still probably just looking at an adjustment that is needed somewhere. If you feel resistance anywhere at all, then you have a different issue.
The one thing that I'm curious about is your process of "rebuilding". These typically aren't rebuilt/serviceable (unless you really know what you're doing). What did your rebuild consist of?
Thanks so much for your reply. I just checked the pump and at full throttle, it does pull out and retract with no issue. This morning, as I spun the starter 'gear', it appeared to be moving more oil than what I noticed yesterday. I dont have access to be able to use a drill (as you did in the video) so perhaps I've not spun it up enough at idle to produce enough oil to be noticeable.
Also, in response to your questions, yes the stop pin is aligned with the dot. Also, I purchased a gasket and seal kit and disassembled and installed those new components in the pump. (Maybe not necessarily a 'rebuild'). At full throttle, it definitely moves oil!
@@matstang1491 It sounds to me that your pump is probably good to go. The quantity of oil pumped at idle is VERY small. At 33:30 in the video, I've actually sped the video up significantly. If you're spinning it by hand, it might not LOOK like anything is pumping unless you do it for a long time. In addition, although you bled the pump, the line going from the pump to the cylinder could have also had air in it... so until you've purged THAT air, your readings could also be off. If the pump moves freely, quantities look good at full throttle and you're getting SOMETHING at idle, odds are in your favor that you're in the ballpark.
Great news. I have been hesitant to start the bike after the rebuild but feeling confident now. Best video on youtube on these pumps. And thank you, thank you for taking time to help me out!
@@hermetheuscoffee I have a similar issue. At idle, nothing. When I tighten the nut down, it doesn't allow the shaft to move up and down when I turn the wheel. When the nut is loose, it can move up and down. Is that normal?
Does the Virago 250 has this pump?
They are not even remotely similar. The pump in this video is an oil INJECTION pump for a 2 stroke engine. It's pumping oil into the crankcase that will then be burned in the combustion cycles. It's nothing like a 4-stroke oil lubrication pump like the Virago.
Best Part is these pumps are all the same. GLAD THIS MAN CALLED OUT THE PEOPLE WHO THINK THERE PUMP IS a faulty part of the bike it's your fault if you starve your engine
Thank you!!!!!
He forgets to mention that the alignment mark is gets lined up when all the slack is out of the cable and the throttle slide is about to break.
Thanks, Ted. That's a valid and important aspect that I left out of this video.
Going down hill pull clutch in and if you half to just give it gas.
Great video but is anyone feeling sea sick with the hand movements so close to the camera? Put the pump down and take your hands out the shot.
I can see what you mean. Sorry about that. I tend to talk with my hands a bit. Noted for future videos!