OK, I have tk22 carbs on my 550 LTD. I started it and it started kind of hard and ran rough. I realized that the #4 cylinder was not firing the pipe was no getting that warm. I've been fighting this for a while, but I do believe that under throttle the #4 fires because the I do have power under throttle and the pipe is warmer.
I have cleaned the carbs spotlessly, adjusted the air/fuel air mixture screws to 1 and 1/4 turn out, checked compression (good at 150 psi), checked spark, swaped plugs and plug cap/wires.
Here are my findings:
The odd part is that I can back the air/fuel mixture screw all the way out and all the way in, makes 0 difference on #4 carb. I do this on any other cylinder and it affects the idle bigtime. At idle I pull the spark plug cap off and no change. I do this to any other plug and I kill the bike. I pull the vacuum cap off the carb manifold and nothing... I do this to another and kills the bike. I took the boot off and put my hand over the throat of the carb and the cylinder started to fire. I sprayed a very small amount of carb cleaner into the carb manifold and get an RPM change, so I have tentatively ruled out compression and spark. I sprayed carb cleaner all over and no RPM change.
Something seems to be wrong with this idle circuit... I can't imagine what though because I have tried everything. The plug is not wet when I pull it, so I think it's just not getting gas on idle.
FYI, stock air box and pipes.
I am completely stumped on this one...Can anyone give me any help on this one?