broncosbp Posted June 2, 2010 Report Share Posted June 2, 2010 last time out at the pit my bike started to sputter, and missfire and loose power like it was starving, just plain running rough and bad, also don't want to idle. took carbs out, cleaned them, checked reeds everything looks fine. now i have to hold the throttle open about half way to even get it to start and it is smoking a lot. it wont idle at all and when i drive it it sputters and dies out when picking up speed. i have 220 jets, k&n filter, pro circuit pipes 20 over on pistons, mikuni carbs with tors removed. anyone have any help for me. i pulled the plugs and they are wet and black. im guessing im running way too rich but i dont know why???? Quote Link to comment Share on other sites More sharing options...
hercalmighty Posted June 2, 2010 Report Share Posted June 2, 2010 I would check your compression. Those 220 mains are small for pipes and a K&N. Sounds like you might have smoked the top end Quote Link to comment Share on other sites More sharing options...
fastbanshee8 Posted June 2, 2010 Report Share Posted June 2, 2010 220 mains with pipes, and a K&N is way too lean. You should have 280's in for mains. Air screws should be open 1.5 turns each. Quote Link to comment Share on other sites More sharing options...
madjimmax Posted June 2, 2010 Report Share Posted June 2, 2010 Those jets seem awfully small. Pro Circuits like big jets for some reason. I'm running Pro Circuits and I'm running a 380 main I also have a lot more mods and port work though. Quote Link to comment Share on other sites More sharing options...
broncosbp Posted June 2, 2010 Author Report Share Posted June 2, 2010 i just did a total top end rebuild about 3 months ago, wsm pistons 20 over all new gaskets and stuff. it was running great until last week. when i pulled the reed cages out from what i could see the pistons and skirts looked ok. there is no binding when i move the pistons up and down. do u think maybe i have something messed up with the carbs? how about the stator and timing. i have an adjustable plate at +4. Quote Link to comment Share on other sites More sharing options...
broncosbp Posted June 2, 2010 Author Report Share Posted June 2, 2010 how about my pilot jets, what size should i be running? i have my idle screw all the way in and still wont idle!!! Quote Link to comment Share on other sites More sharing options...
hercalmighty Posted June 2, 2010 Report Share Posted June 2, 2010 Just because the piston looks good from the intake side doesn't mean the topend isn't smoked. The rings could be fried and you wouldn't know unless you did a compression check. If your running super lean it won't take much to smoke a topend Quote Link to comment Share on other sites More sharing options...
fastbanshee8 Posted June 2, 2010 Report Share Posted June 2, 2010 Take the pilot jets completely out of the carbs, and clean them very well, before putting them back in. Quote Link to comment Share on other sites More sharing options...
broncosbp Posted June 2, 2010 Author Report Share Posted June 2, 2010 ok. ill take the top end apart and check everything. u think a good starting point should be 280 mains? where should i position my needle and what size pilots? this thing is a pain in my ass. never stop working on it. i guess it gives me a reason to be in the garage though Quote Link to comment Share on other sites More sharing options...
madjimmax Posted June 2, 2010 Report Share Posted June 2, 2010 All after market pipes need a 27.5 pilot and if your running lean you can smoke the top end in a couple of hours. And just because its running good it dont mean that its not lean. An engine will scream while its running lean until you burn it up. Just go get a compression tester and you wont have to tear anything apart. What elevation are you at I know that 280s would of been too small for my bike when I was where your at with mods and I'm at sea level. Quote Link to comment Share on other sites More sharing options...
fastbanshee8 Posted June 2, 2010 Report Share Posted June 2, 2010 What size pilots do you have in there now? Make sure the clip on the needles is in the middle groove. Quote Link to comment Share on other sites More sharing options...
broncosbp Posted June 2, 2010 Author Report Share Posted June 2, 2010 sounds like i screwed up after the rebuild. i put 220 mains and 25 pilots in. my buddy has a compression tester and i will do that. also, i had needle clip all the way at top causing even more lean . so ill pull the top end and check everything. do u think i can get away with just rings??? i am at sea level in new jersey. so after all i should be at 280 mains and 27.5 pilots right? thanks for all the input guys. it is very helpful because this is my first banshee!!! Quote Link to comment Share on other sites More sharing options...
fastbanshee8 Posted June 2, 2010 Report Share Posted June 2, 2010 When I used to run FMF's with a K&N on unported jugs, I had 320 mains in, so 280's might be too lean. I forgot my original filter was a foam, and it only needed 280, or 290 mains. I can't say if rings will fix it, buy my guess would be NO. Tear it down, and post up some pics, so we can help answer that question. Quote Link to comment Share on other sites More sharing options...
broncosbp Posted June 2, 2010 Author Report Share Posted June 2, 2010 no prob. ill tear it down and post some pics. probably get to it tomorrow...i hope! what a project these things are. they are a lot of fun though. what should my compression be for each cylinder?? Quote Link to comment Share on other sites More sharing options...
madjimmax Posted June 2, 2010 Report Share Posted June 2, 2010 When I used to run FMF's with a K&N on unported jugs, I had 320 mains in, so 280's might be too lean. I forgot my original filter was a foam, and it only needed 280, or 290 mains. I can't say if rings will fix it, buy my guess would be NO. Tear it down, and post up some pics, so we can help answer that question. I agree totally I would try at least that I think I was running 340s and the only thing different is I was running a cool head Quote Link to comment Share on other sites More sharing options...
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