Hi all i'm new on this forum. I'm having some problems tuning my raptor. I recently went +4mm stroke and 80 over bore to make it a 719. port and polished head with hotcams stage 3 cam. 1mm bigger intake valves and an edelbrock carb. (which is probably a mistake so i hear). My problem is I have a dead spot right above idle it spits and sputters bad. I've tried 93 octane to 110 octane made no difference. changed the needle height from super rich to lean with no change. Changed the float bowl height no change. played with the gap on the plug got worse with more and less gap. it revs out good just has a very bad spot in the throttle range just above idle. Would be great to get some input on what you guys think. Thanks.

 

hmm noone knows i guess. maybe i should just sell the damn thing and buy a 4x4 or a street bike. the engine has a couple hours on it after being rebuilt.

 

I may not be able to answer your question but before anyone can properly answer what you are asking they would need more specifics such as Pipe/compression/air filter/CDI type etc.I can tell you that i have a fully built 690 Raptor that took quite a bit of tweaking to get just right but it was very well worth it eventually.This is simply a guess at this point but you are probably going to remedy your problem with some carb adjustments.

 

bigger pilot jet.

 

well as far as specifics i have an alba pipe full pipe, it's around stock compression all i know fom the kit so i'm guessing 10:1 was a hot rods stroker kit with cp piston with a very small dome on it +4 stroke .080 over bore. air filter is a foam filter with foam outterwear, stock cdi thought about buying a vortex cdi not sure. problem is with the edelbrock carb you don't mess with jets otherwise i'd change a pilot jet. the edelbrock carb you tune the idle to 1/3 throttle by turning a screw in the top of the carb to raise or lower the needle which i've gone from black smoke out the pipe at idle to lean and it didn't affect my problem. to adjust 1/3 to full you change the needle i've even tested this and no luck. Heck i even adjusted the accelerator pump just to try it even though i knew it wouldn't work. i'm all out of ideas lol. I can't call edelbrock for help cuz they don't have tech support for it they just sell the stuff. I've looked at other FCR carbs and for a little more i could just get fuel injection.