banshee36

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.

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?

Switched the reed cages around and it didn't make a difference. Any suggestions?

I have a 1999 banshee with keihin pj34's with 140 mains and 58 pilots and the air screw set out at 1.5 turns on both carbs as well as the needle position being the same on both carbs. Also has v-force 3 reeds. Compression is dead even on both cylinders and have switched spark plugs and spark plug wires and the left cylinder still runs richer than the right. Both exhausts are exactly the same and not leaking anywhere. Has new rings and gaskets. The right cylinder is running perfect. The left cylinder is always running richer whether it's at idle or wide open. The only thing I can think of is reeds but I have no idea how to check them and if they even make a difference in the fuel ratio? Might also switch carbs to see if it changes. Any suggestions?

I was torquing my cylinders down to 20ft lbs and the cylinder stud pulled the helicoil right out. There are no threads left in the cylinder for a timesert or helicoil to hold onto, tried loctite too. Is there anything I can do that can save this cylinder?

I tore the engine down to look at the pistons and replace anti-freeze. I don't know the compression but it seems pretty good. I believe it just needs a carb clean to run better and the plugs look pretty good. I was just wondering if anyone else is running a similar setup with these carbs and what they are running for jets?

Measured the carbs tonight and the models are keihin pj 34 with 140 main jets, 58 slow jets, 1 1/2 screws out on air screw

Just bought my first banshee, it's a 99 bought it for $950 and needs a little work. Engine mods include LRD exhaust with DG slip on, v force 3 reeds, wiseco pistons bored .020 over, twin air filter, and keihin carbs. I bought it and it ran okay but not great so I tore the engine down, replaced coolant, and in the process of cleaning carbs. I realize that banshees have mikuni carbs stock and mine has keihin. The main jets are 140, pilot jets 58. Wondering if this is the correct jetting for the mods that are done to it? I ride at about 1200 ft, 75 degrees. Not sure of the size of the carbs, maybe 28? If you need any more info, let me know. Also, previous owner said to run amsoil dominator at 50:1, is this correct or should I richen it up to be on the safe side?