Bayou 300 Running Rich

[SteveS]

I'm having trouble with a 1988 Bayou 300. It was in pretty tough shape when I got it. It burned oil and needed exhaust. I rebuilt the top end of the motor with a .020 piston, new valves, guides and seals. I got a cobra exhaust pipe and rebuilt the carb. The problem I have now is it runs way too rich, black smoke out of the exhaust, and it will soot up a plug in a matter of minutes. I have reassembled the carb about 30 times and cannot figure it out. I even put all the old needles and jets back in, but nothing seems to help. I thought the aftermarket exhaust could be the problem, but I thought that usually made it run lean? I was thinking about getting a different size pilot jet, but I don't understand why it would be different from stock. I start with the air screw and 2 1/8 turns, but it doesn't seem to make a difference which way I turn it. Anybody have any ideas ?
Thanks
Steve

[QKENUF4U]

float height correct ? needle postion the same ?

[SteveS]

Thanks for responding. I've experimented with the float height, but it doesn't seem to make a difference. The needle is vaccumn operated, so it doesn't have a clip adjustment. I've ordered the stock size main and pilot jet, incase mine have been drilled out, plus one size smaller of each. I've even tried to slip the timing chain 1 tooth, because it is backfiring out of the carb almost like its lean, but yet the plug will soot up. With the latest combination, it will fire twice like it wants to run, then pop back through the carb. I was also curious is there was any part of the ignition system that could be only working intermidently? It seems to have a strong spark, but at this point I'm trying anything. Any help you could give me would be appreciated.
Thanks
Steve

[QKENUF4U]

did you do a jet kit or just guess at the main jet size ?

[SteveS]

Stock it was supposed to be a 128 main jet, and a 38 pilot jet. I originally bought a moose rebuild kit, but the main that came with the kit was stamped 130, but it was the same size as the 128 I took out. The pilot was stamped 38, but the hole was less than half of the one I took out. So my guess was that either the kit was machined wrong, or someone had drilled out the original jets. Since I didn't know where I was at, I ordered a 128 main, 125 main and a 38 pilot and a 35 pilot direct from Kawasaki so I know what they are stamped is what they really are. They will be here tomorrow so I can try them then.
Steve

[QKENUF4U]

the moose kits are supposed to match stock since they are STOCK rebuild kits. i re-read your first thread and it sounds like the pilot may be WAY to big. that pilot with the small hole may be your ticket since the one in it may have been drilled out.
good luck