rejetted this weekend, when I opened up my carbs, this is what it looked like. Left side clean, right side not clean. What caused this?

looks like it's backfiring through your intake

Which could mean that your intake valve is open a little bit during the combustion cycle, which would mean that your intake valve is too TIGHT.

Have you checked your valve clearances yet?  :dunno:

I checked them at 8,000, now have 11,000. Planning on checking them this weekend while I have the tank off due to repainting.

Another possibility is that there is carbon build-up on the valve seat preventing the valve from closing fully.

If that is the case, then what should be done to eliminate the carbon on the valve or valve seat?

Check the compression first. This will tell if there is a problem inside, but it could be valves or rings. To clean the valves, the head would need to be pulled.

There is another way that I heard about....spraying a little water into the carbs while the motor is running. Kind of like steam cleaning your motor.

Quote from: dgyverCheck the compression first. This will tell if there is a problem inside, but it could be valves or rings. To clean the valves, the head would need to be pulled.

There is another way that I heard about....spraying a little water into the carbs while the motor is running. Kind of like steam cleaning your motor.

don't do that.

That doesn't sound too good for the engine, of course what do I know, thats why I'm asking. Any other suggestions.

Quote from: se7enty7

Quote from: dgyverCheck the compression first. This will tell if there is a problem inside, but it could be valves or rings. To clean the valves, the head would need to be pulled.

There is another way that I heard about....spraying a little water into the carbs while the motor is running. Kind of like steam cleaning your motor.

don't do that.

Why not?  I thought a little spray of water could be good for an engine.

Water injection is more common than you think.  It is often done on turbo charged cars to help prevent detonation under extreme boost conditions.  But I've never heard of anybody cleaning valves in this manner.

All old time mechanics in some form or another use water to clean the carbon. They sell some stuff that is actually water with some corrosion inhibitors wihihc is now the treatment of choice. You have to remember these 3 things ... the motor has to be hot hot hot before you inject water, Use steam distilled water, and run the motor for a good 15-20 mins after the last drop of water has made its way out. How and where do you add water ... Air filter ... either spray through it if its K&N type or remove it and spray if its paper or UNI.
Cool.
Srinath.