I need some advise on my 02 prairie 650 that I swamped in a mud bog. I believe that I have a compression problem. I can not get my prairie to run. the engine turns over and I have fuel and spark. I checked the compression and I am getting close to 25psi not with in the usable range according to the book. MUST I have my exhaust connected for my engine to run and get correct compression. I removed my rocker case and cylinder head and the valves appear to be seated and in good working condition as well as the rocker arms and valve gap. I feel that my compression loss is in my piston rings and down into my crankcase and this would also explain some mud in the oil pan. there is a air hose that runs up to the air box from the crankcase and I feel what I believe is blowby coming up from the crankcase into the air box. can anyone tell me if I am suppose to feel any pressure coming up from the crankcase up through the hose in the air box. since I am going to replace my piston rings hoping to fix this blowby problem dose anyone have recommendations on what I should do as far as upgrades while I have my whole top end torn down. I am thinking about going with Wiseco or PBR for replacement parts or upgrades.

Any advise would be greatly appreciated.

Dan

 

I would try to contact Penland Bros. Racing, and talk to Mike P. I don't have the ph. #, but I am sure someone here has it, like Prairiewrench. Also, you might try contacting AllToys here in this forum. Good luck!

 

This may sound strange, but try starting it with pull starter.

 

Same problem with mine at the 15000km mark.... wouldn't start wouldn't pull start either. the Thing is if you fucx with it you can get it going and you would not be lacking power. I found out kawi has an oversize piston too. I got away with just replacing rings etc... only top end. My leakdown was 98 percent.

 

I put a Four Stroke Tech 750 cc kit on mine, when my head gaskets started leaking & my heads got warped from over heating ( severe abuse, don't ask about the stupidity )... I have a friend that had to rebuild, from a similar situation as yours... he had the local dealer rebuild it with Kawi parts... I had the same dealer rebuild mine with the FST 750 cc kit... the FST kit also included some radical cams, heavy duty valve springs, & of course much more displacement... I also had my heads flowed while I had it apart... my buddy & I each spent about $2,700.00, having every thing done ( all parts & labor )... now he wishes he had gone the big bore way, because there is absolutely no comparision between our quads... the aftermarket parts were so much cheaper than the stock parts, that I could have the extra work ( like the heads flowed ), for the same money... you can ask around, but Mickey Dunlops ( FST's ), cams are about the most radical you can get, because the increased displacement, allows thier use, with out any down falls... IMO, this is the only way to go... you can call Mickey, @ (814) 842-6159, between 3:00 & 6:00pm eastern time

 

BTW, Mike Penland's phone number is 706-746-2812. I just happen to have it handy b/c I spoke to him yesterday to get some general info on GNCC racing. I highly recommend calling him with your questions because he is always very helpful with my P650 questions and he seems like a very down to earth kind of guy.

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

Mikey... are you getting pumped for this race yet ??? there is nothing like it...OHHH YAAAA !!!!!

 

Mike W.,
Thanx for asking....Its all I can do NOT to think about the upcoming race!! Seems like I am constantly thinking of everything I need to bring/ what I have left to install on my quad (tether cord kill switch)/ where I want to go to practice/ wondering what the course will look like/ etc. It will be my very first quad race ever... its at a GNCC race with legends like Mike P/Scott Kilby/etc....So YES, I'm very pumped! [img]i/expressions/face-icon-small-smile.gif[/img]

 

djdan;

My point with the pull starter was that the p650 has an auto-decompression on it for starting.

Can't find my manual, so not exactly sure how it works, just wanted to make sure it didn't get stuck on, from the mud, before you did a leak down test.

Good luck.

 

I have not tried to pull start my Prairie. I have the recoil starter in pieces right now because the damn thing won't wind back up. I am going to try the shimm work around and see if that fixes it. I think what you are talking about it is the KACR (kawi auto compression release) which is attached to the cam. it seems to be working fine. book says it either stays swung open or wont wong open. my KACR moves freely so I do not think there is a problem there. I still would like to know if the exhaust needs to be connected in order to be able to start it. Also I would like to know about the crankcase breather hose in the air box. Can anyone start their Prairie and tell me if there is pressure coming up that hose into the air box.

I am very curious about the FST cams.