sl650 big bore kit

[jaybirdjetski]

Hey guys I found a wiseco big bore kit on ebay for my sl650.I already changed my main jets from 82.5's to 102.5's for my updated flame arrester.Do I have to change main jets and maybe the low jets for the big bore kit?It should take me to a 685cc with cyl's bored out

[pcalonge]

One of the Fuji motor guys should really answer this, but:
My old 750 Fuji had adjustable high and low speed adjustments, and I believe that the 650s did also. With the jet change you have already done, you should be in the ballpark on jetting if you can get good plug readings with your current setup.
I believe you have already posted that you have shaved heads and a high flow flame arrestor- the re-jet job you did for these mods should cover the bore increase- the Wisecos should not increase the compression over stock. Just watch your plugs very closely during break-in and adjust high and low as neccessary.
WORD OF CAUTION!!!- the Wiseco pistons are forged rather than cast as most other (including OEM) pistons and require a little more care in installing, break-in, and riding. The pistons will expand from cold much faster than cast, so make sure you warm your ski up slowly (for at least 5 minutes after each cooldown) before you hammer the throttle (with a thermostat in, longer if you did remove the thermostat as you said in a previous post).
These are racing pistons and should be treated like a lot of other high performance mods- carefully.
I suggest reading the many Wiseco piston posts in the aftermarket performance forum above- I found some really good advice on forged piston set-up and use there.
p.s.- I bought a set of the Wiseco's on eBay too, for the next top end job I may need- bought a full set of three with a top end gasket set for less than the price of one piston kit! I'll live with the slow warm-up!! [img]graemlins/buck.gif[/img]

[jaybirdjetski]

COOL THANKS FOR THE ADVICE PCALONGE I'LL TAKE A LOOK AT THE AFTERMARKET FORUM MY SKI IS PRETTY MUCH MAINC.FREE EXCEPT FOR FLUSHING GOOD AFTER EACH USE AND KEEPING THE BAT.CHARGED GOOD LIKE I SAID ITS A 1995 WITH ORIGINAL MOTOR PRBLEM FREE SO I DONT THINK I WANT TO GO CRAZY ON MODS I LIKE THE RELIABILITY IT HAS