One cylinder not firing... White smoke cloud...

[LucPro]

Hey there all... I can't get my bike to run properly. It is getting spark but only one cylinder will spark. I cleaned the carbs as well but I just can't get it to work... Since I cleaned my carbs it spitting out white smoke. I need help!!!

[Big Shot]

Spark on one cylinder means you have an electrical problem.

Stop playing with your carbs!

First things first, switch plugs from left to right.

Is the same side not firing?  (Then it's not your plugs)

Next switch coils from left to right.

Is the same side not firing?  (Then it's not the coils)

Other than make sure you have a good charge in your battery, that's as far as i can take you.

Try it and tell us what happens.


Good Luck, Bob!


Ya sry, "but only one cylinder will spark" threw me off...   

[LucPro]

It's not the spark. I already checked. I am getting spark. I don't think I am getting fuel... Any ideas?

[ATLRIDER]

Please clarify: both cylinders are getting spark but only one is firing?

How was it running b4 you cleaned the carbs?
Did you mess with the airmix screws?
When you cleaned the carbs did you change the sync screw settings?
If air filter is on, spray ether around carb intake manifolds.  Does the engine speed change?
With air filter off, If you spray ether(starting fluid) into the carb with the cyl that's not running, does it make a difference?
Are all your vacuum hoses hooked up? 
What happens if you swap plugs?

[LucPro]

I cleaned the carbs cuz it was running this way... It stays the same if I switch the plugs. I thought a jet might be clogged so I cleaned it. I really think one side is not getting fuel.. But Im not sure... Float height is good... Ideas?

[LucPro]

Where is air/fuel screw?

[fred]

I cleaned the carbs cuz it was running this way... It stays the same if I switch the plugs. I thought a jet might be clogged so I cleaned it. I really think one side is not getting fuel.. But Im not sure... Float height is good... Ideas?

Did you verify your float heights using the clear tubing method? If so, you are likely getting fuel. To make absolutely sure, try to get it running, then take the plug out on the side that won't fire and smell it. If it smells like gas, you've got fuel. You say you're getting spark, how did you verify that? I'd consider swapping coils if I were you, since it sounds like you've only swapped plugs. Also, if you have fuel and you've double checked that you've got spark, check your compression. You can just do it with your thumb if you haven't got a compression gauge handy. Put your thumb over the spark plug hole and try to start the bike. If you can't keep your thumb on the hole, no matter how hard you try, you've likely got good compression. If you can keep your thumb on the hole, you've got problems and need to start looking at your valves...

[LucPro]

I pullled the plug and held it against fins and tried to start it... It was sparking... Should I still try swapping coils...?

[ATLRIDER]

One other thought at this time.  You may not be getting fuel at idle.  Take airfilter off, revup engine 3/4+ throttle momentarily and see if fuel is coming up through the needle opening.  This well tell you if you're getting fuel. That'll also give you an idea if the idle circuit is possibly clogged.  You really need to go about this systemically and follow the ideas others have presented. How are the checks going?

[LucPro]

I got it fixed. I took apart the carbs and thouroghly cleaned every little piece and completely rebuilt the carb... Then it started working great.

[Big Shot]

Grats!