Sled: 2001 Polaris XCF 440
Fan cool Fuji - VM34 mikuni carbs - Runs great at idle, engine acceleration is smooth to 4700 at which point the clutch engages, the engine RPM's drop 2 - 3 hundred and the sled starts to move. Very normal 1/4 throttle performance. At 1/4 throttle the sled goes 10 -12 MPH, engine RPM's are 5000 +/-200. The clutch doesn't shift out unless I'm on hardpack.
The problem is getting the engine to spin past that 5500 - 5700 RPM point. When the engine is cold (not at operating temp) its fine. One lap around the farm, and you have to feather the throttle to get it into the power band.
I bought this sled 6 weeks ago, after purchase I started with stock jetting as my baseline.
I have put in #40 pilots (#45's are stock) and gone from 340 (PTO side) and 330 (MAG side) to 320 and 310 respectively. Little change in throttle response. One common in the changing of the main jets that is quite noteworthy, every change in main jet size, I start with the jet needle clip in the center...every time I have to set the clip in the highest position, or it is horribly unresponsive. That is where the clip was when I purchased the sled. Anyone out there has experience with this model year XCF - and resolved this issue??