The fact that you got less than 5k subscribers is criminal. The information you give us for free is mind blowing. I really appreciate it and hope you continue. Thankyou
Great video! Speaking of cast 2-stroke pistons, a few years back I bought an '09 KTM 300 and was told by the seller that it had the top end done recently. So I proceeded to ride the bike for the next 3 seasons (offroad) until I began having jetting issues I couldn't resolve. After opening the motor up I found I had worn through the Nikasil near the exhaust port and the Vertex piston had a huge crack developing in the skirt. Very lucky I didn't grenade the motor. This was a woods bike, rarely wide open.. but with enough time cracks definitely develop in cast pistons! I now run an hour meter and do the top end every 150 hours. lol.
Thanks and Right on. Hmm, I have a KTM 150 here that started running rich out of no where, we put new reeds in it and checked the carb. Now you have me wondering if it cracked a piston and thats what making it run rich. Will pull the pipe and look up the port. For sure lucky the 300 stayed apart. I guess you had the cylinder replated?
@@UpAllNight91 Yes I had the cylinder re-plated. I just had a look at my old piston (I kept it) and the crack is on the exhaust skirt. Its about 1" long and only on the outside.. it somehow didn't make it through to the inside.. Maybe I caught it early before it fully developed. There are a couple of small chips that are missing inside the crack tho.. probably didn't help the Nikasil lol. Pretty sure the jetting issues were more to do with the worn out cylinder and associated compression loss. Note: My bike was running rich as well and I couldn't seem to lean it out.. It felt like any change I made either did nothing, or somehow made it worse. Thants when I pulled the top end.
@@JonathanVee Ahh ok. Yes this bike was running spot on and mid ride on the track went pig rich. I havent dug into it yet though. But I walked Joey (the owner and rider) through changing out the reeds (he had a spare set on hand) and also checking the carb and all that checked out well. We can shut off the gas and as the bowl lowers the bike runs good again. Indicating whatever is going on its rich. I will dig into it sometime next week and try to figure it out. Who knows, it could have a cracked piston. Guess I wont know till i poke around some.
@ight91 Does it have the factory Mikuni carb on it? I know on the 250/300's there is a gasket that commonly leaks from factory. It's the Jet Block Gasket.. and it will allow fuel to bypass internally causing a rich condition that can't be corrected with jetting. Very common failure point on the Mikuni TMXs that KTM used after switching from the reliable Keihins.
I would also think that a lighter piston/wrist pin would equal less reciprocating mass? Which would be a good thing, which could equal higher rpm's as well? Lastly, I thought the coating on the skirts were to reduce friction? Anyway, thanks for the video.
Yes I do believe the lighter piston free's up revs a little. The coating may help reduce friction some I also read from wiseco some time back it was more about cylinder fitment and reducing piston rattle.
@@UpAllNight91 you definitely changed my opinion on forged vs cast. After this top end is up on my cr250r I’m going to switch to a forged piston. And back to a cast from different brands, and compare them all after the come out with 60 hours on them. One question though, I can see from your video that the forged and cast pistons seem to be the same diameter, so what makes a forged piston noisier at idle?
@@awesomeproducts1582 I dont know but I wanna say its just how the piston is made. The forged piston is a more solid and you can hear it if you tap on the piston with a wrench or something hard. The cast is softer so maybe that helps keep it from making much noise.
Video on gas would be be cool. Octane, leaded vs unleaded, pump vs race gas. Any benefits of running straight race gas vs a 50/50 mix? I’m looking for a good overall race gas for 2 and 4 stroke.
Great info as usual. Thinking at my level OEM cast is fine, but when time to do the top go to forged on a 125. 125s just have to work harder to get you where your going. Off topic but what does it take to get thru the gate at Croom now days? I have titled OHV sticker but it is from 2020. Have FMF Turbine Core 2 internal spark arrestor slip on. Good to go? And thanks for these vids!
Hello and Thanks!. I always bring a shorty and a spark arrester with me to croom. Sometimes its required, most times its not. I believe you just gotta show some type of ownership. I have been told even a simple hand writen bill of sale is enough. I think your 2020 OHV decal will actually be enough honestly. They are not strict at all. My wife buys our yearly pass online and all they require is we plug in the vin number.
Cant go wrong with all OEM parts except for the piston. Thats the way to go. And the RE piston is surely a great piston. I dont really have much experience with anything but the 2003 to current YZ250 cylinder
Yes I have, a few times. I went back to the normal pro lite piston on my last piston but thinking about going back to the racers choice pistons once again. Seeing most cylinder wear is from the rings I'm starting to wonder if the single ring piston can extend the cylinders life some. Just a thought at least.
Hey do you reckon a slower vet guy that doesnt hold the throttle pinned alot and mixes a good premix at 35:1 can get 80 hours out of a forged piston and just replace the rings at 40 hours?
Hello. On a 250 2 stroke, yes slower guy can totally get 80 hours out of a forged piston and rings. I would not worry about changing the rings at 40 hours though. The rings need to seal on two things, the cylinder wall and the piston. Once a set of rings wear into the ring landing on the piston if the rings are going to be replace might as well replace the piston with them for best results. That being said the rings will usually out live the piston on a 2 stroke. I would just run it 80 hours if thats what you plan to do and then replace the piston and rings together.
I will agree less piston slap. Even though they measure the same the forged piston can make more noise. My only issue with the cast stock piston is it can break under heavy race use but otherwise is surely a quiet piston than can crank on some hours. But after I personally broke a few I had to move to forged.
If the pistons are breaking, there's too much piston to cylinder clearance. When the clearance is too big, the piston "rocks," & this squeezes the skirts together (continually making things worse until failure). So both, forged & cast will still break. Tha forged just takes the beating g a little longer before it fails. But, if either are at the point of cracking or breaking, the service interval for the piston is way too long.
@@keithpeterson6108 I cracked a OEM piston in a 2005 RM250 with only 5 hours on it back in the day. They can crack even when everything is 100%. Race fuel does help but no proof there either. I have never seen a Wiseco crack or break (on it own) that was in good shape....Iv seen probably hundreds (that's right) of cast pistons break when in proper condition. Florida also has some of the harshest riding conditions so you add that to a fast, throttle happy rider in a 40min moto and all bets are off. Pretty sure that's why old Honda cr125 manuals of the 90s said replace piston every 10 hours or less.
@UpAllNight91 If the skirts are cracking, it has to do with cylinder clearance. If the top of the piston broke off to expose the ring, that is from detonation. Both will destroy a piston regardless of what it's made from. I've run both in high performance, max effort, snowmobile oval race engines (that have won at prestigious races like Eagle River World Championships) & there is no difference in reliability within the service window of a topend. Even if you run a boosted engine or run the funny gas, a cast piston can live just fine. As the boost or spray levels start to climb, then swapping to a forged piston is needed. If the pistons are holing or breaking on around the dome, it's from detonation. Cracked skirts are from excessive cylinder to piston clearance Honda NSR's cone with cast pistons. Those are the pinnacle of performance in what the oem's make available to the public. I'm not saying cast or forged is better as both have their place. I'm just saying that the oem piston is NOT a reliability issue by any means. A forged piston will take excessive slap for a little longer than a cast piston. However, both would be a danger for breaking & should never be run that long or in that condition. If a cylinder has excessive clearance, a new piston will slap away & cave the skirts in at a MUCH faster rate than if it was a proper piston to wall clearance. So, if you're experiencing a short piston life, check the jug. If the engine is all good (as in actual measurements), check for exhaust leaks by the cylinder or cracks in the pipe. An engine WILL ingest dirt through the exhaust leak. Of the exhaust is sealed, confirm the emgine doesn't ingested dirt through the intake via pulling it through the airfilter. If all of that is good, give it a richer oil ratio! There are so many guys running too little oil amount. Oil is your engines friend for both long life but also power! I've dynoed & tested oils & ratios. Less oil is NOT good for power & even worse for engine component life.
@@keithpeterson6108 Hello. I have seen perfect cylinders on new bikes break pistons with less than 20 hours. Not once but many times. And then the broken piston is removed and replaced with a forged piston (same exact cylinder) and the bike has gone on to sometimes over 150 hours on that cylinder with normal piston changes as needed, no problems. Its happened, they buy the bike new, I warn them. They dont believe or dont want to put the money in a new bike and they end up breaking it on the track. I put a wiseco in and after that it lives, lap after lap, after lap. One guy (The 2022 YZ125 I did the video on with a broken piston) told me he would run it a few more weeks then change it, it only made it one more week. These are new bikes (as well as older ones) giving up with a cast piston. For the YZ250 smoker I often say if your a C rider it will be fine and seem bulletproof but once you move to the B class or above it will start giving you problem, just how it is. It doesnt seem to matter how healthy everything checks out, how well the piston and cylinder measure, its more about the riders ability to use the motor hard and heavy for a long time. Swap out the cast for a forged and the bike will not break another piston for that rider. I have seen this so many times.
Please clarify for the folks at home, you don’t have to drill holes in the cast pistons for the exhaust bridge! Only forged. Also, can you do a video on measuring squish?
Hello. I thought the day of needing to drill holes in the piston where over, both cast and forged. I could be wrong but anymore piston manufacturers drill holes for us when needed and don't when its not. I know I never have to drill holes anymore.
I'm running .037 squish on my cr80 because I took .020 of the cylinder base. When I miss shift the motor isn't smooth wide open like you would expect. But then I didn't have my new wiseco crank checked for true before install
@@danb37 Hello. In theory yes but so does going from part throttle to full throttle. If you took 0.20" off the cylinders base you lowered all the ports, this can be what you are feeling at high revs, alower exhaust port will cause the motor to feel more labored up at the top end.
Do you drill holes on your piston? My 01 YZ250 has around 15 hours on the new top end and I took off the pipe and noticed some lines on the piston which leads me to think that I should have drilled some holes on it.
Hello. Do not drill holes in the YZ250 piston. The holes in the exhaust side of the piston are for bikes that have a exhaust bridge in the middle of the main exhaust port. The YZ250 does not have a bridge in the main exhaust port. Drilling holes in it would cause the pre compression is the crank area to bleed into the exhaust, which would cause poor performance.
Any chance you’ve ever used Athena power valves on an OEM YZ125 cylinder (2005-2021)? I can get them for $140 compared to about $240 for new OEM valves. One of mine looks a bit damaged at the tip and I’ve got a top end rebuild coming up. Not sure if I should change and not sure if Athenas work and are better/worse than OEM. Thanks bro!
I havent ever used them but they should fit and work just fine as athena stuff is usually plug and play. Do you know if they are titanium like the OEM ones?
Kinda off topic but 2023 yz 250X jetting issues. Stock and only has under 3 hours. Fouling plugs. I'm at Sea level. Just wondering if JD kit is a good solution? I know you know YZs.
Hello. I wouldnt buy the JD jet kit. its not needed really. The same jets in that kit you can buy yourself. Also when buying jets try to use keihin jets and avoid the china cheap jets. You can get the keihin jets from any yamaha oem parts section in the carb section. What premix oil are you running and what oil ratio are you running? Assuming the jets are still stock, What do you have your air screw set at currently?
you are wrong about piston pins, i've been running Vertex piston for my husqy fe 250, it has DLC coated pin, OEM and wossner does not, my forged vertex was in better shape then OEM after same ours, only lost a little bit of compression. Overall great video, i would like to hear about versions of pistons, as Vertex has 8 options i believe, replica, race, hc, pro race, GP etc.
Hello. I have noticed alot of the KTM bikes (husqy gas gas) dont use the DLC coated pin. But the jap bikes do. What I didnt know is vertex offers a piston with a DLC coated pin. Thats good to know and I will look into that because I do really like the DLC pin, it surely keeps wear down in that area.
I really try to watch ur videos, but the rooster I just can’t do it. It’s like nails on a chalkboard. Can’t u move him away from ur shop if you know ur filming?
LoL, sorry man. He can be a pain I know. I do get a lot of comments from people who enjoy having him in the videos and you are only the second one who has complained but I do know it can be a pain to listen to sometimes. Maybe I can just limit him down some, especially on the days that he seems to be extra noisy. Thanks for watching though and commenting.
The fact that you got less than 5k subscribers is criminal. The information you give us for free is mind blowing. I really appreciate it and hope you continue. Thankyou
Thank you and your welcome!
And in 3 weeks he has more💯👍🔥😮💨
@@AmazingBlaze0👍😉
It's all about the chickens gotta have shop chickens
@@darrellmabry699 🤣🤣🤣 LMAO!!!
You got the jetting on Beavis spot on, he rips!!!
😆 Dude he lives on the pipe lol
It just the way you explain stuff just makes sense in my head 🎉🎉🎉
😁👍
Love these videos you’ve been doing on all the components of bikes. You’re a great resource!
Thanks! Glad to hear that!
Great video! Speaking of cast 2-stroke pistons, a few years back I bought an '09 KTM 300 and was told by the seller that it had the top end done recently. So I proceeded to ride the bike for the next 3 seasons (offroad) until I began having jetting issues I couldn't resolve. After opening the motor up I found I had worn through the Nikasil near the exhaust port and the Vertex piston had a huge crack developing in the skirt. Very lucky I didn't grenade the motor. This was a woods bike, rarely wide open.. but with enough time cracks definitely develop in cast pistons! I now run an hour meter and do the top end every 150 hours. lol.
Thanks and Right on. Hmm, I have a KTM 150 here that started running rich out of no where, we put new reeds in it and checked the carb. Now you have me wondering if it cracked a piston and thats what making it run rich. Will pull the pipe and look up the port. For sure lucky the 300 stayed apart. I guess you had the cylinder replated?
@UpAllNight91
You're not gonna see the crack if you look up the exhaust port. The cracked will he on the intake side.
@@UpAllNight91 Yes I had the cylinder re-plated. I just had a look at my old piston (I kept it) and the crack is on the exhaust skirt. Its about 1" long and only on the outside.. it somehow didn't make it through to the inside.. Maybe I caught it early before it fully developed. There are a couple of small chips that are missing inside the crack tho.. probably didn't help the Nikasil lol. Pretty sure the jetting issues were more to do with the worn out cylinder and associated compression loss.
Note: My bike was running rich as well and I couldn't seem to lean it out.. It felt like any change I made either did nothing, or somehow made it worse. Thants when I pulled the top end.
@@JonathanVee Ahh ok. Yes this bike was running spot on and mid ride on the track went pig rich. I havent dug into it yet though. But I walked Joey (the owner and rider) through changing out the reeds (he had a spare set on hand) and also checking the carb and all that checked out well. We can shut off the gas and as the bowl lowers the bike runs good again. Indicating whatever is going on its rich. I will dig into it sometime next week and try to figure it out. Who knows, it could have a cracked piston. Guess I wont know till i poke around some.
@ight91 Does it have the factory Mikuni carb on it? I know on the 250/300's there is a gasket that commonly leaks from factory. It's the Jet Block Gasket.. and it will allow fuel to bypass internally causing a rich condition that can't be corrected with jetting. Very common failure point on the Mikuni TMXs that KTM used after switching from the reliable Keihins.
Hey Beavis we're having class here! Do you mind? Lol. Almost 5k subs buddy...on your way to the top!!
Yeah Beavis! LoL 5K, I know man that's crazy! The channel is growing so dang fast. I'm actually blown away, hard to believe!
You deserve it!
@@dougw585 Thanks buddy! Its been fun!
Awesome video... answered all my questions I had about the differences. Since I'm more of a woods/rocky rider, stock piston it is.
Right on! Glad to hear it helped.
I would also think that a lighter piston/wrist pin would equal less reciprocating mass? Which would be a good thing, which could equal higher rpm's as well? Lastly, I thought the coating on the skirts were to reduce friction? Anyway, thanks for the video.
Yes I do believe the lighter piston free's up revs a little. The coating may help reduce friction some I also read from wiseco some time back it was more about cylinder fitment and reducing piston rattle.
Haha best video I’ve seen all day
Nice!
.. do you have a video on engine break-in.
Great videos! ...
Thanks! No I don't but Thats a good idea for a video to make. Thanks again!
Thanks for posting this!!! Appreciate it
Your welcome. Thanks for watching! Appreciate ya!
@@UpAllNight91 you definitely changed my opinion on forged vs cast. After this top end is up on my cr250r I’m going to switch to a forged piston. And back to a cast from different brands, and compare them all after the come out with 60 hours on them. One question though, I can see from your video that the forged and cast pistons seem to be the same diameter, so what makes a forged piston noisier at idle?
@@awesomeproducts1582 I dont know but I wanna say its just how the piston is made. The forged piston is a more solid and you can hear it if you tap on the piston with a wrench or something hard. The cast is softer so maybe that helps keep it from making much noise.
I soo needed this.. thanks for taking the time to make this in full detail.. great job.
Another great video!!!
Thanks!👍
Wiseco wrist pin in a stock yz250 or rm250 piston to change the weight to your liking some. Old trick just leaving here for the archives.
Hmm, Why dont I get a notification when you comment on these videos? I do for everyone else.
@@UpAllNight91 Im in stealth mode.
Well that one came in
Great video. Thanks a lot
Video on gas would be be cool. Octane, leaded vs unleaded, pump vs race gas. Any benefits of running straight race gas vs a 50/50 mix? I’m looking for a good overall race gas for 2 and 4 stroke.
Thats a good idea. Thanks, will start thinking on that and collecting what info I can for a video.
Great info as usual. Thinking at my level OEM cast is fine, but when time to do the top go to forged on a 125. 125s just have to work harder to get you where your going. Off topic but what does it take to get thru the gate at Croom now days? I have titled OHV sticker but it is from 2020. Have FMF Turbine Core 2 internal spark arrestor slip on. Good to go? And thanks for these vids!
Hello and Thanks!. I always bring a shorty and a spark arrester with me to croom. Sometimes its required, most times its not. I believe you just gotta show some type of ownership. I have been told even a simple hand writen bill of sale is enough. I think your 2020 OHV decal will actually be enough honestly. They are not strict at all. My wife buys our yearly pass online and all they require is we plug in the vin number.
Appreciate the heads up! 3.5hrs drive.@@UpAllNight91
@@kenitsanoutragecandia3939 surely a little bit of a drive. Might want to camp with a drive that long.
Yup. Don't want to spend more time driving than riding. Best to make it a 3 day weekend. Camped there a long while back.
@@kenitsanoutragecandia3939 For sure. 3 days is perfect!
I'm thinking OEM cylinder, crank, bearings and seals with RE wiseco piston.. what you think? You have experience with other YZ250 cylinders?
You was making me crack up with those 56's at the end😂😂
Are the used ones really lighter tho? That carbon has to weigh something 🤷
Cant go wrong with all OEM parts except for the piston. Thats the way to go. And the RE piston is surely a great piston. I dont really have much experience with anything but the 2003 to current YZ250 cylinder
well thats true. Didnt think about the carbon.
Hahhahaha!
Have you ever run the single ring 808 wiseco racers choice piston in the YZ250?
Yes I have, a few times. I went back to the normal pro lite piston on my last piston but thinking about going back to the racers choice pistons once again. Seeing most cylinder wear is from the rings I'm starting to wonder if the single ring piston can extend the cylinders life some. Just a thought at least.
Hey do you reckon a slower vet guy that doesnt hold the throttle pinned alot and mixes a good premix at 35:1 can get 80 hours out of a forged piston and just replace the rings at 40 hours?
Hello. On a 250 2 stroke, yes slower guy can totally get 80 hours out of a forged piston and rings. I would not worry about changing the rings at 40 hours though. The rings need to seal on two things, the cylinder wall and the piston. Once a set of rings wear into the ring landing on the piston if the rings are going to be replace might as well replace the piston with them for best results. That being said the rings will usually out live the piston on a 2 stroke. I would just run it 80 hours if thats what you plan to do and then replace the piston and rings together.
@UpAllNight91 hey man, thanks so much for your time and advice. Your the best guy on youtube, hope your channel keeps growing
@@malikedwards2180 Your welcome and Thanks Brother!
I feel that the oem piston last longer than the wiseco that I tried in my yz250 also less piston slap with oem.
I will agree less piston slap. Even though they measure the same the forged piston can make more noise. My only issue with the cast stock piston is it can break under heavy race use but otherwise is surely a quiet piston than can crank on some hours. But after I personally broke a few I had to move to forged.
If the pistons are breaking, there's too much piston to cylinder clearance. When the clearance is too big, the piston "rocks," & this squeezes the skirts together (continually making things worse until failure). So both, forged & cast will still break. Tha forged just takes the beating g a little longer before it fails. But, if either are at the point of cracking or breaking, the service interval for the piston is way too long.
@@keithpeterson6108 I cracked a OEM piston in a 2005 RM250 with only 5 hours on it back in the day. They can crack even when everything is 100%. Race fuel does help but no proof there either. I have never seen a Wiseco crack or break (on it own) that was in good shape....Iv seen probably hundreds (that's right) of cast pistons break when in proper condition. Florida also has some of the harshest riding conditions so you add that to a fast, throttle happy rider in a 40min moto and all bets are off. Pretty sure that's why old Honda cr125 manuals of the 90s said replace piston every 10 hours or less.
@UpAllNight91
If the skirts are cracking, it has to do with cylinder clearance.
If the top of the piston broke off to expose the ring, that is from detonation.
Both will destroy a piston regardless of what it's made from.
I've run both in high performance, max effort, snowmobile oval race engines (that have won at prestigious races like Eagle River World Championships) & there is no difference in reliability within the service window of a topend.
Even if you run a boosted engine or run the funny gas, a cast piston can live just fine. As the boost or spray levels start to climb, then swapping to a forged piston is needed.
If the pistons are holing or breaking on around the dome, it's from detonation.
Cracked skirts are from excessive cylinder to piston clearance
Honda NSR's cone with cast pistons. Those are the pinnacle of performance in what the oem's make available to the public.
I'm not saying cast or forged is better as both have their place. I'm just saying that the oem piston is NOT a reliability issue by any means. A forged piston will take excessive slap for a little longer than a cast piston. However, both would be a danger for breaking & should never be run that long or in that condition.
If a cylinder has excessive clearance, a new piston will slap away & cave the skirts in at a MUCH faster rate than if it was a proper piston to wall clearance. So, if you're experiencing a short piston life, check the jug. If the engine is all good (as in actual measurements), check for exhaust leaks by the cylinder or cracks in the pipe. An engine WILL ingest dirt through the exhaust leak. Of the exhaust is sealed, confirm the emgine doesn't ingested dirt through the intake via pulling it through the airfilter. If all of that is good, give it a richer oil ratio! There are so many guys running too little oil amount. Oil is your engines friend for both long life but also power! I've dynoed & tested oils & ratios. Less oil is NOT good for power & even worse for engine component life.
@@keithpeterson6108 Hello. I have seen perfect cylinders on new bikes break pistons with less than 20 hours. Not once but many times. And then the broken piston is removed and replaced with a forged piston (same exact cylinder) and the bike has gone on to sometimes over 150 hours on that cylinder with normal piston changes as needed, no problems. Its happened, they buy the bike new, I warn them. They dont believe or dont want to put the money in a new bike and they end up breaking it on the track. I put a wiseco in and after that it lives, lap after lap, after lap. One guy (The 2022 YZ125 I did the video on with a broken piston) told me he would run it a few more weeks then change it, it only made it one more week. These are new bikes (as well as older ones) giving up with a cast piston. For the YZ250 smoker I often say if your a C rider it will be fine and seem bulletproof but once you move to the B class or above it will start giving you problem, just how it is. It doesnt seem to matter how healthy everything checks out, how well the piston and cylinder measure, its more about the riders ability to use the motor hard and heavy for a long time. Swap out the cast for a forged and the bike will not break another piston for that rider. I have seen this so many times.
Please clarify for the folks at home, you don’t have to drill holes in the cast pistons for the exhaust bridge! Only forged.
Also, can you do a video on measuring squish?
Yeah video on sqishh band be good
He already did th-cam.com/video/q2KPCoq1Mm8/w-d-xo.htmlsi=2Tp-J6yONvY5xt95
He already has th-cam.com/video/q2KPCoq1Mm8/w-d-xo.htmlsi=2Tp-J6yONvY5xt95
Hello. I thought the day of needing to drill holes in the piston where over, both cast and forged. I could be wrong but anymore piston manufacturers drill holes for us when needed and don't when its not. I know I never have to drill holes anymore.
@@macpac3803 I do have head videos where I check the squish but i will put together a video covering squish on its own and how to check.
Great info and hand gesturing.
Will running a very close squish or higher than stock compression change the balance of the crank at wide open revs?
I'm running .037 squish on my cr80 because I took .020 of the cylinder base. When I miss shift the motor isn't smooth wide open like you would expect. But then I didn't have my new wiseco crank checked for true before install
@@danb37 Hello. In theory yes but so does going from part throttle to full throttle. If you took 0.20" off the cylinders base you lowered all the ports, this can be what you are feeling at high revs, alower exhaust port will cause the motor to feel more labored up at the top end.
hey man one question can i use a OEM black cotet Piston pin on a aftermarket wiseco piston? i have a yz 250F 2017
You can if they measure the same width. I haven't checked to see if it does but is so then yeah
Do you drill holes on your piston? My 01 YZ250 has around 15 hours on the new top end and I took off the pipe and noticed some lines on the piston which leads me to think that I should have drilled some holes on it.
Hello. Do not drill holes in the YZ250 piston. The holes in the exhaust side of the piston are for bikes that have a exhaust bridge in the middle of the main exhaust port. The YZ250 does not have a bridge in the main exhaust port. Drilling holes in it would cause the pre compression is the crank area to bleed into the exhaust, which would cause poor performance.
Any chance you’ve ever used Athena power valves on an OEM YZ125 cylinder (2005-2021)? I can get them for $140 compared to about $240 for new OEM valves. One of mine looks a bit damaged at the tip and I’ve got a top end rebuild coming up. Not sure if I should change and not sure if Athenas work and are better/worse than OEM. Thanks bro!
I havent ever used them but they should fit and work just fine as athena stuff is usually plug and play. Do you know if they are titanium like the OEM ones?
Kinda off topic but 2023 yz 250X jetting issues. Stock and only has under 3 hours. Fouling plugs. I'm at Sea level. Just wondering if JD kit is a good solution? I know you know YZs.
Hello. I wouldnt buy the JD jet kit. its not needed really. The same jets in that kit you can buy yourself. Also when buying jets try to use keihin jets and avoid the china cheap jets. You can get the keihin jets from any yamaha oem parts section in the carb section. What premix oil are you running and what oil ratio are you running? Assuming the jets are still stock, What do you have your air screw set at currently?
We’re is a 2019 yz 125 jetted for on elevation from factory?
lol, I dont think they sell that option
@@UpAllNight91 I’m asking we’re the bikes are jetted for from factory?
@@SethMacgillivary Sea level at 70 degrees
@@UpAllNight91 oh ok thanks and the more u go above sea level the richer it will run
@@SethMacgillivary correct. So as you go up in elevation you will need to lean out the jetting.
you are wrong about piston pins, i've been running Vertex piston for my husqy fe 250, it has DLC coated pin, OEM and wossner does not, my forged vertex was in better shape then OEM after same ours, only lost a little bit of compression.
Overall great video, i would like to hear about versions of pistons, as Vertex has 8 options i believe, replica, race, hc, pro race, GP etc.
Hello. I have noticed alot of the KTM bikes (husqy gas gas) dont use the DLC coated pin. But the jap bikes do. What I didnt know is vertex offers a piston with a DLC coated pin. Thats good to know and I will look into that because I do really like the DLC pin, it surely keeps wear down in that area.
I really try to watch ur videos, but the rooster I just can’t do it. It’s like nails on a chalkboard. Can’t u move him away from ur shop if you know ur filming?
LoL, sorry man. He can be a pain I know. I do get a lot of comments from people who enjoy having him in the videos and you are only the second one who has complained but I do know it can be a pain to listen to sometimes. Maybe I can just limit him down some, especially on the days that he seems to be extra noisy. Thanks for watching though and commenting.