Restoring a 98 and noticed the piston has hit the powervalve. Checked the powervalve and it seemed to have snapped the leverage part. I am now thinking that might explain the spring not functioning properly to limit the range thus hitting this piston, nasty stuff. Thanks for explaining and showing in detail 🎉
Man your the best for posting this vid, I doing a top end job for my friend and noticed the hole in the power vavle where you put your screw driver in to remove the powervavle assembly, I thought that he was missing the part and cut a screw driver to make a dowel and lock tighted my home made dowel Into the hole thinking that the piece with the groves piveted on it , I started the bike and it not running right at all , now I now what I got to do to make her run good again , great post 1996 yz250 will run great again tommorrow after some tinkering
Thank you. Restoring a 98 and my power valve leaked. I took it apart replaces the orients and seals and was unsure I had It right. I also learned how to tighten it correctly with that dowel pin hole.
dude thanks for putting this up I have a 95 yz250 that i got as a project and i have been scratching my head on the power valve looks like i gotta order some stuff and do some fabrication.
Thanks for this video I just finished rebuilding my 94yz250 from bottom up... I had the bike apart for 4 years was looking for a video on how to connect the linkage and this popped up thanks again
thank you for the clear video. turns out my power valve someone left the tightening pin in for whatever reason and it broke off one of the ears on the fork. also my valve is actually broken in half and theres some shiny parts on the valve. piston is fine though and rings are intact so im a lucky man. i ordered new $200 valve and o rings and hopefully itll have power again. ive been fighting with this bike trying to figure out why it has no power. and this is probably why!
Thanks for watching! The power valve it self is two parts that have a long allen head bolt that holds them together. Not sure if that's what your referring to when you say it's broke. Good luck on the fix!
@@Keith1212 yea but also the pins that hold it in place aswell are all wallowed out to the point where one side has sharp metal and i just dont wanna risk it. I think the locating pins are neccesary
Thanks man. That's the reason I made this vid. Once I figured out what I needed and what I couldn't order I knew someone else would be in the same boat someday. Thanks for watching!
I'm pretty sure that the part(s) you say you cannot order as they are greyed out are available. Look on the cylinder / cyl head schematic rather than governor. The later bikes (96+) seem to be missing a cylinder head schematic so you might have to bring up a '95 or earlier to find this. The PV is largely the same from 89-98 with the exception of a few washers/rings. Yamaha part no 3JE1193701 for your home made spacer. Hope this helps, and please correct me if I am wrong
Dude if it wasn’t for your video I would’ve never gotten this power valve back together properly I had the parts correct it’s just the spring thing I didn’t know you had to spread it open
Extremely good video on the power valve. I run Castor 927 for my premix. 36/1 You can run at 40/1 Do you see all the carbon build up on his exhaust and top of his piston. If you run the 927 none of this will be there and your power valve will not have all the carbon build up on it just a heads up
So if my power valve is leaking thick oil out of it, what part do you think it is? I heard something about the power valve shaft developing wear and not having a proper o-ring seal or something? Is that part hard to come by?
+LCH_Entertainment It will leak a bit of oil on the side with out the linkage. It even has a bolt in the cover to drain the excess. The other side that has the linkage won't leak as much but a tiny bit under normal riding. The oil keeps the power valve lubed and working properly. Now if you have a ton of very thick oil or sludge in there it needs to be cleaned out as it will slow the power valves movement. If you haven't replaced the O rings on either side then I would do that while giving it a good clean to get rid of any thick oil or sludge. Then lube it back up with pre mix and put it back together. Thanks for watching!
+Keith1212 Also you can order the O rings from places like partzilla, bike bandit, and rocky mountain atv websites. Just use there bike finder menu to put in your year make and model. Normally partzilla is the cheapest for OEM parts.
+LCH_Entertainment On the side with the cover that says "Yamaha" on it, there is a cover inside that cover with a gasket beneath, so a gasket for the outside cover and one for the inside cover. That side has direct access to the exhaust and Im guessing acts at abit of an expansion chamber, hence the drain bolt. The side with the linkage will have a very small o-ring inside the linkage, with a larger o ring, and then an oil seal at the very end. If its leaking bad then replace all of those.
Be careful of levering the link arm up like that, it takes the spring tension off the governor ramp, and can let the drive pin drop out. Looking at how far the valve arm is dropping down, the closed stop - part of the bush assembly on the left side - is getting worn, and this lets the valve rotate further down and contact the piston. You need to check this between top end inspections.
Hi keith! I have question to you! Im rebuilding a 97' wr 250, and i disamble de ypvs and where you put allen i have a pin that doesnt let move easily the powe valve ...so if a take the pin out will affect in something ,its necesary that pin or i can pull it out and let the power valve whit it??? I will aprecciate an answer! Greetings from Chile!
my 93 yz125 power valve is the same and i realized the previous owner left the installation pin (the notch that holds the power valve from spinning) in there so does that mean ive been riding without hitting the actual powerband this whole time??
www.partzilla.com/parts/search/Yamaha/Motorcycle/1996/YZ250H1/GOVERNOR/parts.html You can't order the spacers that I made in the video, but everything else is here. Thanks for watching!
rocky mountain atv or bike bandit. I prefer rocky mountain atv though. Just look up your bike. Mine was Yamaha>1997>yz250. then click the box on the side that says governor. The part I think your referring to is part #1 on the schematic. Good luck hope this helps!
+Brent Mutersbaugh Same shape as the outline you see in the video. Has four bolts and a gasket to hold it on. You can look up the scemetic of the bike and see the cover on bike bandits website. Just search the year make and model.
www.partzilla.com/parts/search/Yamaha/Motorcycle/1996/YZ250H1/GOVERNOR/parts.html ? Should be able to find everything here. Except the couple things that are grayed out. Thanks for watching!
Here's an ebay link with a couple used push rods if that's what you were needing. www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313.TR0.TRC0.H1.Xyz250+3SP-11990.TRS0&_nkw=yz250+3SP-11990&_sacat=0
i have a 96 yz250 and the power valve linkage will not move when it it running the valve moves smooth and there is still tension on the linkage but when it gets into the high rpm the linkage will not open the valve. any ideas?
+glenn mo Sounds like your YVPS Governor is maybe not working correctly. If there is no tension on the actuator arm then something is definitely wrong. Take off the right side engine cover and inspect the power valve governor.
+David Ray you may have let the dowel that holds the governor on in the bottom end get stuck. you would have to remove the clutch cover to see. This normally happens if you flex the linkage with out the governor flexing it due to engine rpm. I'd take the clutch cover off as i mention and be sure the dowel is in the proper position.
+Kevin Stearns It's all about the port timing on a 2 stroke exhaust. smaller port equals more power down low. Larger port means more power on the top end. And everything in between! With out the power valve you would have a lot of top end but no low down torque. You would have some but not as much as you could have.
Some of the smaller pieces on the video not listed on partzilla I had to make. Pretty simple if you have a garage full of bits and bobs. Thanks for watching!
Hola cómo pondría apunto la válvula de escape de un Yamaha yz 250 93 por la pongo como la pone en el vidio y no abre xq primera sequedad rebulacionada pero en baja 2ya la abre la válvula un saludo
I don't know the size for sure, chances are your not gonna find it at a local hardware store though. It's part #5 on this diagram. www.partzilla.com/parts/search/Yamaha/Motorcycle/1996/YZ250H1/GOVERNOR/parts.html Thanks for watching!
+Brent Mutersbaugh There's one on ebay atm. On ebays page next to the search bar click advanced. Then on the page it opens on the left side click "by item number" and search for this number "111857418284". That's the same as the one for yz250.
750 ml as it states on the cover near the oil fill. Also there is an oil check bolt that you can remove and fill the oil till it drips out of the hole, replace the bolt when it does and your good to go. The oil check bolt is located on the same side as the oil fill on the bottom left of the crank case. It will be the only one with a washer on it. Thanks for watching!