Snowmobile Forum banner

Wilcat 650 performance help

245 Views 5 Replies 2 Participants Last post by  kccats
I'm running a 1990 650 wildcat drivetrain on a custom chassis for drag racing. I've exhausted all my time trying to get this setup running properly. I would really appreciate some other opinions please. Fresh build, new cylinders (std. Bore), wiseco pistons, 2 new 44 mikuni carbs. Factory arctic cat ignition. I cannot get the engine to open up completely under a load to make power. Factory clutch. I've tried everything with jetting that I know. I'm running at 500ft above sea level and 60-80°F. Running 50:1 and NGK br8es. I know these engines are designed for colder climate but we usually have very good service running snowmobile engines with appropriate jetting here. I cannot find much information to diagnose ignition system but I don't hear or feel a miss. It's just very sluggish. Revving without a load it sounds nice and crisp. Thanks for your time!
1 - 6 of 6 Posts
You are taking me back!
My 88 650 was VERY Fast
What all did you do on porting?
Get the 88 CDI box
Boyseen reeds
.030 off heads
And Alot of porting
I have the 44 Power Jets
I couldn't get enough fuel either
Twin fuel pumps were stock
The Power jet added fuel at wide open
See less See more
I got it close now. My secondary clutch wasn't working right. I haven't had any port work done yet.
THAT'S where the performance is!
My 88 was Dynoed at 145 hp
I had a write up in SnowTec mag about why my highly tuned 88 650 with Way more HP was NOT as fast as my then stock 98 ZR600! (back in 98)
Who done your porting work?
I do all my own for the past 40 years!
I can walk you through it all!
1 - 6 of 6 Posts