My brother n law bought one identical to this one back in the 70’s, i was like 14 he let me ride that thing whenever i wanted, it ran excellent , same color too.
I really enjoyed your video I think you’re headed in the right direction that it’s electrical I think trying a coil that you know is good it’s a good place to start. The bike appeared to have and sounded like it had a lot of power for a trail bike were you able to assess that with the problems you were having. Look forward to the bike running correctly And seeing how it competes against the Suzuki 185. Look forward to your next video
Those old CT series bikes had an issue with the points jumping. I used to carry a car condenser when out and about because the condensers also had a bad rap. on my CT's and DT's I used to set my points at .010. Over time I didnt even need to carry a feeler gauge with me any more cause I could set them by eye. Also those bikes grounded through the tail light which I see you dont have so might also look for a bad ground. I learned that one the hard way.
Been thinking about you mentioning neighbours and such regarding noise...as a means to consider for mitigation of noise is the old skool enduro/isde sound measurement testing, etc. is using a section of inner tube zip tied to the end of the silencer. Doesn't make them silent naturally, but certainly knocks the DBs down a bit.
So sick man! I was at mid ohio too this year. we have a 1972 (if i remember correctly) LT100 and a DT250 from that general time as well. those old yamahas are some fun bikes to ride!
I would check the carb first for any debris floating around, on my DT125 the float pin isn't very tight fitting in the pegs and can slide when the carb is leant over. It could be something electrical near the exhaust, getting too hot. Good luck finding and fixing it
That’s what I was hoping for…thought maybe the main jet rattled loose but the carb checked out ok. I’ve narrowed it down to points or stator. And thanks!
Does the machine have points? I can’t remember if so make sure condenser is or has a good ground it sounds like a grounding issue it drops out and picks right back up I only say it cause hard parts usually just fail unless it’s a cracked coil a broken kill switch could do it as well I guess but I’d check ground just my opinion and a bad switch will show up in the ground test😎btw awesome video a great command of a machine in trouble!!
Thanks Dave, yeah it’s got a points system. I’ve narrowed it down to points or stator. I replaced the plug, tried a good working coil, replaced the condenser, checked the carb to make sure the main jet didn’t fall off or the needle didn’t get hung up. Fingers crossed it’s just the points! Waiting for them to arrive.
The idle circuit is lean (ringningningc2hen you roll off throttle) but sounds close enough that mix/air screw can fix it. Further up the rpms it's raggy, but get idle circuit right play w needle & main jet from there. Make sure you are on a high octane fuel - for an old engine 1:40 mix prob good, but if it's not running lean, reducing may clean it up some more.
Thanks Robert, I’ve narrowed it down to points or stator (hopefully just points). Tried a different coil, plug, checked the carb. It was running perfect until something went haywire. Crossing my fingers it’s points lol
i think your float height is slightly high but not the issue, just something to fix. measure the stator resiistance and compare it to the service manual to be sure its not the issue. new points are always nice and i would throw a generic 1 wire condenser at it too, rather than spending large and waiting. possibly a plug? is it bought online or retail because theres lots of copies sold online.
@@Garage2Trail just get a GM ignition condenser from your local parts store and bolt it to the coil. Run the wire to the wire coming from the bottom end and done. Easy to try while you wait
@JyveKilla one step ahead of you! Thank you though. Unfortunately that didn’t work either. I got a Mallory 400 condenser mounted up under the tank now next to the coil as you suggested.
One idea that I did not see mentioned.....check the spark plug BOOT. I've had a bad/loose connection between the internal wire and the boot. Remove the boot, cut the wire back 3/4", then put the boot back on. Just another idea if the points don't fix the problem.
I think the carb is running weak - air getting in somewhere ...... did you chuck in a rebuild kit? Or, carb could be basically worn. I couldnt keep an old TY in tune until l completely rebuilt the carb.
@@Garage2Trailthats good to have narrowed it down - hopefully thats the fix. I remember from a million yrs ago that a lad at school had an old FS1E (fizzy) and that would run really rough and smokey on a regular basis and that was because the bike would eat points and condensors. Not sure if that might also indicate coil issues?
I wish it would have been that simple. I was expecting to find the main jet off or the needle hung up. Unfortunately they carb is spot on. Narrowed it down to points or stator. Tried a new plug, working coil, and new condenser already.
I think I’ve narrowed it down to the points. Got a new set on the way. It ran perfect and gradually got worse. I was messing with the points after and closed the gap which greatly improved things. The current set is pretty worn.
@@Garage2Trail yep points are are cheaper. But it doesn’t make sense with the points unless it’s consistent. Vibration shouldn’t affect them. Have you checked all the wiring no breaks or bare places. I had the points plate screws come loose on my 72 cl100 the other day I kicked it for ever then checked it and it jumped time
When the power kicks in it's like a rocket
I love the look of that bike. Very retro 70s. Nice job getting the bike going to this point.
Thank you!
Awesome. My buddy has a few. Love to ride that for the day.
My brother n law bought one identical to this one back in the 70’s, i was like 14 he let me ride that thing whenever i wanted, it ran excellent , same color too.
Cool! The metal flake in the tank with that gold color screams 1970s. It fits it perfectly
I really enjoyed your video I think you’re headed in the right direction that it’s electrical I think trying a coil that you know is good it’s a good place to start. The bike appeared to have and sounded like it had a lot of power for a trail bike were you able to assess that with the problems you were having. Look forward to the bike running correctly And seeing how it competes against the Suzuki 185. Look forward to your next video
Thanks! Yeah this thing is a little rocket. I’ve narrowed it down to points or stator. Got a set of new points on the way.
Those old CT series bikes had an issue with the points jumping. I used to carry a car condenser when out and about because the condensers also had a bad rap. on my CT's and DT's I used to set my points at .010. Over time I didnt even need to carry a feeler gauge with me any more cause I could set them by eye. Also those bikes grounded through the tail light which I see you dont have so might also look for a bad ground. I learned that one the hard way.
I’ve narrowed it down to the points and stator…new points already ordered and on the way! Hopefully that’s it
Been thinking about you mentioning neighbours and such regarding noise...as a means to consider for mitigation of noise is the old skool enduro/isde sound measurement testing, etc. is using a section of inner tube zip tied to the end of the silencer. Doesn't make them silent naturally, but certainly knocks the DBs down a bit.
Thank you! I’ll have to keep that in mind. Appreciate the heads up on that 👍
So sick man! I was at mid ohio too this year. we have a 1972 (if i remember correctly) LT100 and a DT250 from that general time as well. those old yamahas are some fun bikes to ride!
Nice! Can’t go wrong with an old Yammie!
What a cool bike! I’m about to try and make my 1974 Ossa 250 run again.
I almost bought an Ossa Trials bike that was for sale local to me. Missed out though.
Please keep us posted on the problem and how you correct it. Thanks for sharing.
Will do! I’ve narrowed it down to possibly points or stator…hopefully worn points
I would check the carb first for any debris floating around, on my DT125 the float pin isn't very tight fitting in the pegs and can slide when the carb is leant over. It could be something electrical near the exhaust, getting too hot. Good luck finding and fixing it
That’s what I was hoping for…thought maybe the main jet rattled loose but the carb checked out ok. I’ve narrowed it down to points or stator. And thanks!
I never had a 175 yamaha i love it i had suzuki 185s then a 250 bultaco pursang i love the videos
Thank you!
That is a head scratcher for sure. I don't know but I hope you get it sorted because that bike is too cool not to be out riding.
I got a taste of how awesome it is when it was running crisp…this is top priority now lol
Nice bike 😊are you gonna test the xr250 be good to see 😊thanks
I have the XR200 if that’s what you mean 😊. I will have that in the woods soon too!
Does the machine have points? I can’t remember if so make sure condenser is or has a good ground it sounds like a grounding issue it drops out and picks right back up I only say it cause hard parts usually just fail unless it’s a cracked coil a broken kill switch could do it as well I guess but I’d check ground just my opinion and a bad switch will show up in the ground test😎btw awesome video a great command of a machine in trouble!!
Thanks Dave, yeah it’s got a points system. I’ve narrowed it down to points or stator. I replaced the plug, tried a good working coil, replaced the condenser, checked the carb to make sure the main jet didn’t fall off or the needle didn’t get hung up. Fingers crossed it’s just the points! Waiting for them to arrive.
The idle circuit is lean (ringningningc2hen you roll off throttle) but sounds close enough that mix/air screw can fix it. Further up the rpms it's raggy, but get idle circuit right play w needle & main jet from there. Make sure you are on a high octane fuel - for an old engine 1:40 mix prob good, but if it's not running lean, reducing may clean it up some more.
Thanks Robert, I’ve narrowed it down to points or stator (hopefully just points). Tried a different coil, plug, checked the carb. It was running perfect until something went haywire. Crossing my fingers it’s points lol
Hope it's an easy fix. Got my dt100 running again. I pinched a wire from the stator. Now i get to rebuild the clutch.
Thanks me too!
i think your float height is slightly high but not the issue, just something to fix.
measure the stator resiistance and compare it to the service manual to be sure its not the issue.
new points are always nice and i would throw a generic 1 wire condenser at it too, rather than spending large and waiting.
possibly a plug? is it bought online or retail because theres lots of copies sold online.
I’ve narrowed it down to points or stator…checked the carb, coil and plug. Hopefully it’s just points!
@@Garage2Trail just get a GM ignition condenser from your local parts store and bolt it to the coil. Run the wire to the wire coming from the bottom end and done. Easy to try while you wait
@JyveKilla one step ahead of you! Thank you though. Unfortunately that didn’t work either. I got a Mallory 400 condenser mounted up under the tank now next to the coil as you suggested.
@@Garage2Trail maybe give the points a good draw file off the bike while you wait? 😂
I plan on doing that too! Probably tomorrow I’ll get to mess with that.
One idea that I did not see mentioned.....check the spark plug BOOT. I've had a bad/loose connection between the internal wire and the boot. Remove the boot, cut the wire back 3/4", then put the boot back on. Just another idea if the points don't fix the problem.
Thanks for the pointer! I did try that as well…been monkeying with it over the past week…really hoping the points are the culprit!
I Would Say That The Float Is Sticking
When U Ride Over Rough Stuff The Float Is Lifting And Catching Somewhere In The Closed Position
That thing has top end power like a YZ.
It really does have a lot of punch. I can’t wait to get it running good again
Good luck tracing the problem . The bike sounds like me I work some times then don't a few kicks and I work some more
Lol thanks! It absolutely ripped before it started doing this. I have points on the way after eliminating other things suspect.
I think the carb is running weak - air getting in somewhere ...... did you chuck in a rebuild kit? Or, carb could be basically worn. I couldnt keep an old TY in tune until l completely rebuilt the carb.
Carb and intake checks out ok, tried another coil and condenser, new plug….narrowed it down to points or stator.
@@Garage2Trailthats good to have narrowed it down - hopefully thats the fix. I remember from a million yrs ago that a lad at school had an old FS1E (fizzy) and that would run really rough and smokey on a regular basis and that was because the bike would eat points and condensors. Not sure if that might also indicate coil issues?
My new to me mc1m90 rotary dud this then stopped. Had to be electrical
I think when you take float bowl off you will find trash form the tank in there.
I wish it would have been that simple. I was expecting to find the main jet off or the needle hung up. Unfortunately they carb is spot on. Narrowed it down to points or stator. Tried a new plug, working coil, and new condenser already.
I think its coil as its always been missing under light load?
I was hoping that was the case, but I took one off my working DT250B and it didn’t make any difference unfortunately 😔
If you're using the stock 1974 dt airbox you might Not be getting enough air flow And don't use a double foam element. These motors need to breathe
I think I’ve narrowed it down to the points. Got a new set on the way. It ran perfect and gradually got worse. I was messing with the points after and closed the gap which greatly improved things. The current set is pretty worn.
Hey, any idea where I can find a set of clutches for a 1969 Yamaha AT1?
Punch the part number into an eBay search. That’s where I get 90% of my parts
Any idea how I find the OEM part number?
Check out CMSNL.com. They have every Japanese bike made pretty much. You can even find hard to find stuff on their site occasionally.
Where is the rear light?
Didn’t find one for it yet
acts like somethings grounding out
Hi its one of them problems is it this or that? I'm thinking Electrical m8
Yup, it’s one of those problems that rear it’s ugly head after you get it running and running good. I’ve narrowed it down to points or stator.
Maybe coil or coil wire
Tried another coil and plug, checked carb and I’ve narrowed it down to points or stator. Hopefully points lol
@@Garage2Trail yep points are are cheaper. But it doesn’t make sense with the points unless it’s consistent. Vibration shouldn’t affect them. Have you checked all the wiring no breaks or bare places. I had the points plate screws come loose on my 72 cl100 the other day I kicked it for ever then checked it and it jumped time
Appears to be fuel issue
I thought maybe the main jet rattled loose or the needle clip got hung up…not the case. I’ve narrowed it down to points or stator.
Nice work nursing it back. Patience pays off.
Thanks, I won’t stop until it’s running perfect!
@@Garage2Trail No doubt. 👍
Like some of the other commenters might be electrical.seems lile i had a loose wire and it caused a problem like that .hopefully very simple
I’ve narrowed it down to points or stator…hopefully points lol