banshee36 Posted July 11, 2011 Report Posted July 11, 2011 I have a 1996 Banshee with keihin PWK carbs, fmf pipes, aftermarket cylinder head (not sure what brand), wiseco pistons bored .30 over, no air box lid, and it runs on 110 octance. The problem is that it misses/sputters between 1/4 and 3/4 throttle but if you keep it wide open it runs great. It also idles perfect. I have tried every needle position from rich to lean, tried main jets between 128 (which were on when I bought it) all the way up to 158 with no change and done plug chops in the range where the plugs have gone from black to brown to white depending on the needle position. Swapped stators with a known good one, Cleaned carbs, changed plugs, and made sure all carb boots were tight, carbs are synced. Compression is good. The previous owner supposedly ran 120 octane in it, but I don't have anywhere near me to get that but it runs great wide open and at idle so I don't think thats the problem? I've worked on these things a lot but I'm lost on this one. I'm leaning towards an ignition problem but not sure what it would be? Any suggestions? Quote
jlsparky7 Posted July 11, 2011 Report Posted July 11, 2011 Timing Key intact.? Timing advanced? Whats the compression? Quote
banshee36 Posted July 11, 2011 Author Report Posted July 11, 2011 (edited) Timing Key is good, the timing was advanced 4 degrees when I got it and thought that was the problem, changed it to zero and it still does the same thing. Compression is 120 on both sides, checked it with a $30 tester so not sure how accurate it is. Edited July 11, 2011 by banshee36 Quote
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