1 Cylinder not firing

[5twins]

You're going to have to provide some more and better info on the bike, like what year it is and what ignition system it has (points or electronic). Without that info, you won't get much help other than wild guesses.

 

[fredintoon]

carbs are cleaned and cleaned again. she is getting fuel and still nothing. i bought it as a bike that has not ran in 3 years. the guy had it stored proper, and ran all the gas out of the carbs and cut the petcocks off. i am not getting a good spark on number one no matter what i do.

Hi gofast,
try swapping the ignition over.
How you do that depends what year the bike is and what's been done to it.
If the bike is a 1980 or later it's only got one coil with two plug wires and all you can swap is the plugs and the cap ends of the plug wires.
If the bike is 1979 or earlier it's got two coils etc and you can swap the plugs, the feed wires from the points and the plug wires.
If the bike has been retrofitted with an aftermarket ignition say what it is and someone will advise you.
If you did the swapover right and the fault is with the ignition the problem will move to the other cylinder.
If the fault stays where it is, there's a fuel problem despite all the cleaning efforts.

 

[gentlemanjim]

the float bowls maybe getting fuel, but the float needle may be stuck shut or set incorrectly. Did you squirt a little carb cleaner in the inlet of the carb that is not firing and see if fires?

 

[fredintoon]

Hi jim,
carb cleaner works for that? I got a can of quickstart that's got Ether in it.
Yeah, try that first, before tinkering with the ignition.

 

[gentlemanjim]

That confirms its the carb

 

[oldcoal]

A simple compression gauge is only around $20 if even that much at an auto parts tore. Some may even rent you one. What happens if you swap the plugs form one cylinder to the other?? Maybe the problem will follow the plug. Black as you say says it is running way to rich and is gas fouling.

 

[hooser]

If you can get running spray WD and check for a intake air leak on the right side.

 

[azpunkr]

I'm having the same problem. Left exhaust pipe stays cold to the touch after running for a bit. I've cleaned the carbs 3 times now. Both plugs are getting spark. I'm totally at a loss. It just all of the sudden started doing this. Any thoughts on which direction I should go next?

 

[fredintoon]

I'm having the same problem. Left exhaust pipe stays cold to the touch after running for a bit. I've cleaned the carbs 3 times now. Both plugs are getting spark. I'm totally at a loss. It just all of the sudden started doing this. Any thoughts on which direction I should go next?

Hi azpunkr,
Fuel problem answer is usually clean 'em yet again. Especially the slow running and enrichener circuits.
(One time Mr stupid tried rebuilding his ignition for a week to no avail. Carb clean did the trick in an hour.)
There's 3 different ignition fault trees depending if your bike is '79 or earlier (points ignition) '80 or later (TCI ignition) or any year that has aftermarket (Pamco/Boyer-Bransden/other) ignition.
It really saves posting back and forth if you add a signature line to your posts saying what year & model bike you have and what mods it has.