got a 06' wolverine w 400km's on it! scenario: hit a field of snow at high speed forcing the white fluffy stuff all over the bike, and i got stuck! no big deal!! got unstuck and went home! on my way, noticed lack of power, top speed dropped! seemed like it got a cold! brought the bike inside , dried it out and the next day i started it with some difficulty ( choke all the way) !!!! so here are the steps that i took to fix the problem. changed the gas, spark plug, looked for demp connections, changed belts, cleaned the carb, airbox, clutch(new grease) checked the exaust, checked the valve clearence and last but not least, i got the compression tester out and found the problem( i think!!!) i only have 125 psi's( 181 psi's is needed!)
what could have caused this on an almost new engine??????? now my next test is a leak down test to see if it might be a cracked valve or burned rings. if anyone has had any similar problems, please let me know! it might help others on the long run! thanks

 

something in the Top end is hosed..But I doubt it's from hitting one snow bank..You sound like you know your way around a quad..Take of the top end and look for carbon build up on the valves and piston..Maybe you a running way to rich,with 400km's of trail riding that could cause these problems..Why you are at it get rid of those crappy Yamaha rings and piston and put in a better one..And if you really feel good throw in a Hotcam wile everything is broken down..How did the plug you took out look??Black/fouled??

With my 03 In the winter it always runs like crap,will not start without full choke and on summer setting(Idol/air,fuel mix)it wont run at all,have to turn the idol up and run it at half choke till it get hot(that is hard in cold winters lol)But I don't get the power loss like what happened to you..I think the choke thing is normal to Wolverines in the winter..But your compression problems are something else that is wrong in your top end..

 

Your right on the money with your tests. The leakdown will tell you the story. My bet is rings and a scuffed piston.

 

or you could have tuliped your valves, your cleareances would still be ok. Don't think you broke it. I'd do whats been stated tear it down and go from there.

 

thanks for the advice guys, really appreciate it!! a tear down is my nxt step and will probably tell me the story! hopefully nothing major! worst case scenario is new piston and rings! best case scenario is abundence of carbon build up from over jetting it! in any case, i wouldn't mind putting in a high compression piston, and thats were i get lost! i like using oem parts , and im not sure what brand i should use for aftermarket piston and rings????? any suggestions???? thanks again!!!!!!

 

Let us know what you find out so we can all learn.

 

well i found the problem!!!!! the intake valve was leaking, so i got a friend to seat it properly! he says te compound was never done on it! after getting the engine back together i found the carb was also running like crap! the diaphragm had a rupture on it! fixed it and now it growls like a true wolverine!

 

Good deal and good job!! Glad you found the problem and got it running. Happy riding

 

Glad you got her runnin again.