Ive got an 02 P650,been a good machine,but I got it a little wet on the last ride(OK,I swamped it bad.....again)and I cant git it to start now.Ive got spark,gittin good clean fuel(I drained the tank and the float bowls)but initial leak down tests point to some internal damage,the front cyl is blowin out the exh,so I m guessin I bent a valve there.The rear cyl wont hold much press either but it seems to be blowin into the crankcase,so Im kinda thinkin I might of bust a piston or at least a ring.Which brings me to questions bout BB/Strokers. Im tryin to find out whats out there and Im not findin a lot of info.Anyone tell me what works fer them,or at least who I can talk to?I dont know If I should just use factory parts to make a 750,or if there is something better/cheaper on the aftermarket.Any help here would be appriciated.

 

Here's a good post on this topic.... http://atv.dnsalias.com/forum.cgi?vi...&viewtopic=554

PS - For a BBK install, you expect to spend approx. $2,000 to $2,500 for total cost including labor to press the sleeves in, etc.). Your other option is to bore out the cylinder a little bit (2mm) and install overbore Wiseco 11:1 pistons and bigger cams (Web Cams or Hotcams). I just did the same thing, but did not bore out my cylinders (I used stock bore size Wiseco 11:1 pistons). New Pistons and Cams is a cheaper alternative than doing the BBK and will hopefully be just a reliable as a stock motor. Just something to think about.

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

 

How the hell did you break a ring and valve? I have a buddie with an Arctic Cat 650 V2 (kawi motor) and I have witnessed him drown his quad twice. To get it running after, he just keeps hitting the electic start button although it wont crank over (hydraulic siezure). He just keeps on hitting the button over and over finally it will crank then start and spit water out of everywhere for 10 - 15 minutes, it comes out the exhaust, the CVT vent, the airbox, milky oil blows out of the airbox breather its a mess but the damn thing keeps running its unbelievable.

 

650... are you sure it was a proper leak down test, rather than a standard compression test ??? the the centrifical compression release won't allow a standard compression test...

IMO, if it was hydrolocked, most likely cause of poor compession could be one of 2 things... a bent valve, or a dry cylinder ( lacking of enough oil to allow the rings to seal properly )

 

Mikey:Thanks fer the link and advice,guess I'll see if the cyl is wrecked or not then decide which direction to go.Did the higher comp and cams make a pretty substantial difference?What is a set of those cams worth anyhow?Any body have any idea what kinda power the carbs and intake will support before becoming a major cork?
Sammy:I cant belive I hurt it either,it still spun over easy with the starter and its been swamped worse than this beforeI'm still not totaly convinced I did ,but it sure dont lookk good.And I cant git it to start no how.
Beatle:Ya I did a leak down test...90 psi goi in and 10 psi on the other guage,showin some real major leakage.The manual says a compresion test should git you 41-81 psi on a warm motor despite the decompression .Mine made 40 or so but on a dead cold motor.I was plannin on tryin to redo the leak down test with some oil in the cyls,but havent got to it yet.I did try oil fer the comp test and it didnt make much difference,but even bein at the bottom end of the spec,youd think it would still run.Please if any one has any ideas,I aint too proud to listen [img]i/expressions/face-icon-small-happy.gif[/img] .

 

If you are looking to send you motor somewhere to have the work done check out Fundy Powersports. I believe they are located in Canada and I have seen some video of a prairie built by them lay it on a yfz450 in a 100 yard drag. I may be mistaken but I believe the prairie was a 700 or 720, never the less the v twin will make tons of power without going to an extremely large boar, with the right tuning,

 

650,
Not yet sure how much power the hi comp pistons and aftermarket cams will provide...I just finished getting my quad back together last Sunday and hope to go test it out this weekend. I'll report back on these forums when I do that.

I think you can get a set of Wiseco Pistons and Web Cams for a P650 for about $500 or so. The Hotcams cost a little more than Web cams, but there is no core exchange with the Hotcams.

Yes, I believe you are right about the carbs being too small for most BBKs...seems like most folks running a BBK are also using DAJs to add fuel to the carbs. I had DAJs installed on my old 2003 P650 (no BBK) for the past year and these DAJs worked ok, but not great. I had some minor issues with them being too sensitive if I rode in a lot of dust or on a very cold day, otherwise they seemed to work ok. When I recently rebuilt a 2002 P650, I decided not to use my old DAJs on this motor. Instead, I installed Dynojet needles and changed the main jets.

Good luck and happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

650,

I have a 650 with a stroker crank, making 854cc, lots of power.

both fundy Power sports and Four stroke teck have big and small bores.

 

854...that is truly bent,did that crank come from four stroke tech?If ya dont mind....what did that cost by the time it was all done?How can I git a hold of the guys at FST?

 

I did the same thing in a mudhole but mine did`nt quit running just started blowing blue smoke and burning oil ,I was also going to get the BBK but decided to go with the high comp pistons and the hotcams it`s in the shop now.

www.fourstroketech.net is the website for mickey dunlaps shop he only takes calls from 4 til 7 pm