one cylinder isnt firing

I'm beating my head against a wall once again. my second cylinder from the left isn't firing. Ive checked the spark spark plug, plug wires,. compression and i even tried a spare coil i had laying around, I runs but very poorly. When i pull the plug out it is soaked with gas. Is there something in the carb that I am missing? Ive checked pilot and main jets to make sure they are not clogged. I'm running out of Ideas.

the smarter ones are sleeping....bump this post tomorrow to the top eastern u.s time

fuel + compression + spark = go boom

you are on the right track.....did it run before?

before what?

swap coils on the same bike...

swap plugs with a new one...

check valve clearance....

battery is good and 12 volts or more....

F$%^ i dunno....the smart ones need sleep...i dont

Checked the sparkplug cap? Inside is a 5000 ohm resistor that can become intermittent/fail with time. Unscrew it from the sparkplug wire & test it with a multimeter. Also tried a new,fresh sparkplug" Some brand other than NGK?

With the spare coil, use existing spark wires or different set...?

If same set of plug wires/caps...
Swap plug wires 2 & 3 (same coil/ignition fire), if problem now goes to plug # 3, then that plug cap (as mentioned), or plug wire/connection is crapola.

80kz650cafe wrote: ...second cylinder from the left isn't firing... Ive checked the spark spark plug... When i pull the plug out it is soaked with gas. Is there something in the carb that I am missing? Ive checked pilot and main jets to make sure they are not clogged. I'm running out of Ideas.

Does a brand new plug have fat blue sparks when attached to the cap with its base held grounded against the engine? If so, would indicate that ignition system function though the secondary loop is okay (coil; plug wire; cap; plugs; and their connections to each other). This would tend to rule out a spark issue as cause of combustion failure.

Excessively rich mixture might prevent combustion, one possible cause being too high fuel level.
Could perform the clear tube test to see whether fuel level is within specs.

Good Fortune!

Im pretty convinced my spark is good tried multiple plug wires and plugs. I starting to lean toward the too much fuel, due to soaking wet plug, how would i check this

For checking the Fuel Level in the carb, Patton has some great pictures/ tutorials. Do a search and you should find them or he will probably post them up in this thread for you. But also check to see that the Choke/ Starter plunger is also seated and not leaking. As it can also cause over rich fuel mixture. So can you post your compression readings fro the test that you preformed?

The carb is designed to best perform with a certain specified level of fuel inside the float bowl.
A too high fuel level results in an excessively rich mixture throughout the throttle range.
A too low fuel level results in an excessively lean mixture throughout the throttle range.

The objective of the CLEAR TUBE TEST is to determine height of fuel level inside the float bowl.
When the test is performed correctly, the level of gasoline visible inside the tube will match the level inside the float bowl.

Carb must remain in a stable level position during the test, such as motorcycle on center stand or otherwise held steady in a balanced level position. Or carbs may be held level on the workbench.

First -- prevent gasoline supply to the carb, and then drain the float bowl.
Which leaves an empty carb with a dry float bowl.
Next, attach the clear tube and hold it steady alongside the carb.
Then, allow gasoline to enter the carb.
The incoming gasoline passes through the float valve and into the float bowl.
As the level of gasoline rises inside the float bowl, the level of gasoline also rises inside the clear tube.

If the float valve is correctly functioning, the float will rise high enough to close the float valve, at which time gasoline stops entering the float bowl, and remains at a fixed level inside the float bowl and at the matching level visible inside the clear tube (which level will be either too high or too low or within specs).




Learning the actual fuel level inside the float bowl completes the clear tube test.

If the fuel level is too high or too low, "adjusting" the fuel level is a separate procedure, which involves changing how soon the rising float stops gasoline flow through the float valve.

Good Fortune!

If the "choke" circuit fails to completely close, such condition will contribute to an excessively rich mixture in the combustion chamber.



When operating the choke lever in normal fashion on a fully assembled motorcycle, should be able to watch the carb mechanism simultaneously raising and lowering the plungers. And notice whether any plunger might be failing to fully open or fully close.

Good Fortune!