Its Alive!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Madbuffalo]

So the bike idles well (1,000-1,200rpm's) but coughs and dies around 3,000rpm's. The fact that it's idling well leads me to believe your timing is good. This sounds like a carburetor issue. At idle fuel is flowing through the pilot jet and the bike is running well. Then as you turn the throttle, induction raises the slide and needle making the main jet begin to open. This is when the bike dies. So it sounds like either you aren't getting enough fuel to the carburetors to sustain the main jets or the mixture through the main jets is wrong.

- Verify that the carbs are getting enough fuel: When the bike dies immediately pull the fuel line off the carburetor. Then loosen the float bowl drain screws. If fuel comes out you know the carbs are getting fuel. This also tells you the floats are working.

- If the carbs have fuel then the mixture though the main jet is likely the problem. What size mains do you have? Stock is L: 110, C: 107.5, R: 110. Some forum members use all 110's but that's another story for another time. Stock needle is "4 DN 18-3" with the clip on the center setting. You mentioned you have new jets. Was it a keyster carb kit? If so I've heard the needle they give you is wrong, although I wouldn't think it would cause the bike to die entirely. While you have the carbs apart also check the slide diaphrams. These raise the slides and if one is punctured/torn it will cause the needle to function improperly. You should also check the venturi passages. Blow air through them one carb at a time and make sure the air flow is roughly the same through each. If not you may need to run a wire though them to make sure there's nothing lodged inside. I use a strand from a braided bicycle brake line. You probably already know but be careful doing this (steel is harder than aluminum and a scratch in the passage could alter airflow) and don't ever run wire through a jet.

- Is there any difference when you turn the choke on or off? If not it may be stuck on which would definately cause excessive smoking and dying at higher rpm's.

- Last, I promise, is have you isolated for sure which cylinder(s) are failing? You mentioned you thought the left and right? Or do all 3 fail at 3,000rpm? An easy way to check is to pull off a spark plug cap and try reving the bike up on just two cylinders. Alternate which cap is off watch the tachometer for differences. A much less accurate test is once the bike has warmed up touch your hand to each of the exhaust headers and see if they all burn your hand the same. That might sound wierd but it got me off the side of the road once when a condenser quit.

[Madbuffalo]

Could someone offer a second opinion and/or verify what I've said? I'm no expert on this stuff and would hate to be leading stinger in the wrong direction. The blind leading the blind and all that. Thanks guys.

[stinger1133]

I will tear the carbs down again and go through them. The bike warms up and the headers are hot to the touch. I tried that when I didnt see any kind of smoke activity from the center cylinder. The main jets are numbered 110,107.5, 110.

[Coyote]

If you are sure it's getting enough fuel. you might try raising the needles a notch.

[stinger1133]

Well tore them down and cleaned them again thoroughly. I got it started and now its popping in the exhaust and spitting from the carbs but not smoking like it did before. Now the smoke is about normal. Not excessive. I have tried adjusting timing but not getting it set to one good spot. It will load up then spit back a large puff through the carbs then die.