I changed my jetting to:
6DH7 Needle, middle clip
Q0 Needle Jet
2.5 slide
40 Pilot
350 Main
It still runs terrible. I am running out of patients quickly, thoughts of parting the sled out are crossing my mind. I rebuilt the entire sled from the ground up over a year ago, and I have been trying every since to get it running right. The NOS odometer reads 32 miles, all of which were painful.
It will start and idle good. When I hit the gas, after a sluggish hole shot, it pulls strong (lifting the skis) until it hits 7,500ish rpm, then it will bog and lose rpm. It doesn't appear to be affected by the amount of throttle input. The longer I hold the throttle, the more rpm it looses. Plugs are a grayish brown color and are typically wet when checked. It doesn't seem to smoke excessively, so I assume the oil injection is working properly.
A little history on the sled: rebuilt crank from Crankshaft Services, new crank seals, all new gaskets, stock bores, stock porting, uncut head, stock pipe, 39.5mm Miks, Invader airbox, stock rebuilt clutches, timing has been set per the manual, new high flow single mikuni fuel pump, carbs are not setup for a primer, new belt, all new fuel lines and filter, running Klotz oil.
What I have tried/checked: Swapped the pipes, CDI box, and coils. Cleaned the airbox, checked the pipes for mouse nests, verified the oil injection was set correctly, several sets of new BR9ES plugs, I have only roughly synced the carbs, verified the carbs were opening all the way. Fresh premium fuel (same fuel that runs great in my other sleds), there is no fuel in the pulse line, and probably more that I am forgetting...
Anyone have any ideas??? I have built MANY snowmobiles (a few Invaders), motorcycle's, but this is my first Interceptor. I am a technician trained in troubleshooting, but this thing has me STUMPED!