Power Valve Cleaning

[robbieisurfriend]

I have been having spooge and exhaust blow out on my leg and engine case on my YZ 250. I took the cover off to find that there was no gasket, just red silicone. I pulled the linkage off of the valve and the damn lever broke on me. It was cracked and it just broke in my hand. No big deal, ordered another one already. Also the oring on the face of the power valve is completely swollen and messed up but I cannot tell by the diagram which one it is. I was going to try to take the valve out and clean it up and lube it and put it back in but I honestly couldnt figure out how to get it out, even with the diagram and manual. I have both ends off and can turn it freely on both sides. The side opposite the governor has an allen head bolt on it. Do I need to remove that to be able to remove it. I have heard with many bikes you have to remove the engine to get them out but I have plenty of access on both sides on my bike, just cant figure out how. Also when I get this thing back together how do I know what position it should be in to put the linkage back together (assuming I can figure out how :o ).
Im sorry, I guess im retarded or something because even Clymers cant teach me. Thanks.

 

[fatboyslim]

If you have a manual, take out all the little peices and clean everything you can and get a new gasket. Putting them back together is pretty easy with a manual. Or you can print a page off bikebandit.com and that will give you and alright picture of all the little peices.

 

[cjfmx]

doe's anyone know how to set the power value on a 1990 yz 125 i set it by the manual and it run's like the choke is on. if i set it wide open then it run 's but at high rpm's it start's missin can anyone help me ?????????

 

[cjfmx]

doe's anyone know how to set the power value on a 1990 yz 125 i set it by the manual and it run's like the choke is on. if i set it wide open then it run 's but at high rpm's it start's missin can anyone help me ?????????

 

[cjfmx]

need help how to set a power valve on a 1990 yz 125

help help help!!!!!!!!!!!!!!!!!!!!doe's anyone know how to set the power value on a 1990 yz 125 i set it by the manual and it run's like the choke is on. if i set it wide open then it run 's but at high rpm's it start's missin can anyone help me ?????????

 

[kx125412]

To cjfmx:

1. Don't send three messages within 10 minutes that all state the same thing but with minor variations thats not going to do you any good
2. On those bikes theres no adjustment on the powervalves, they close at low rpm and when the powervalve governer kicks in it opens, there's nothing you can do.
3. Don't jack other peoples threads make your own about your problem and maybe someone nice will answer.

And to the threadstarter, I have the same year YZ mine just isn't a WR. These powervalves are incredibly easy to install and uninstall there's nothing to em. On the left side of the powervalve there will be a punch mark that goes up. And check the stop for any wear, and any wear on the face of the powervalve. These stops can wear out causing the valve to rotate too far and rub the piston. Everything else goes back on pretty easy, it can really only go on one way. Make sure when you torque the bolt that goes through the powervalve you stick a punch in the hole and the the little notch on the piece thats attatched to the actuator rod. This keeps the rod from moving and you wont break it again.

 

[robbieisurfriend]

To cjfmx:

1. Don't send three messages within 10 minutes that all state the same thing but with minor variations thats not going to do you any good
2. On those bikes theres no adjustment on the powervalves, they close at low rpm and when the powervalve governer kicks in it opens, there's nothing you can do.
3. Don't jack other peoples threads make your own about your problem and maybe someone nice will answer.

And to the threadstarter, I have the same year YZ mine just isn't a WR. These powervalves are incredibly easy to install and uninstall there's nothing to em. On the left side of the powervalve there will be a punch mark that goes up. And check the stop for any wear, and any wear on the face of the powervalve. These stops can wear out causing the valve to rotate too far and rub the piston. Everything else goes back on pretty easy, it can really only go on one way. Make sure when you torque the bolt that goes through the powervalve you stick a punch in the hole and the the little notch on the piece thats attatched to the actuator rod. This keeps the rod from moving and you wont break it again.

Thanks a lot that is very helpful but I am still not understanding how to remove it completely. On bikebandit and my manual there is no reference to the allen head bolt on the left side of the bike. Do I hold the key head that the arm goes on to on the other side then remove that screw to make it come free? I am afraid to find out the hard way so I figured it was worth making an idiot out of myself to save some grief. thanks again.

 

[kx125412]

http://www.bikebandit.com/houseofmotorcycles/yamaha-motorcycle-yz250wrw-1989/o/m8890 go to the governor
Look at part 1, thats the tab with the u-shaped indent im talking about. You put a punch so it sits in that and in the hole in the cylinder so when you take the bolt out it doesnt twist the arm up or down. You have to do this otherwise youll break the arm or something else. If you take everything apart slow you can see how it all goes back together. And i'm rebuilding my brothers 125 this week and its pretty much the same deal I can take pictures for you. Probably wednesday or thursday.