Soot inside carb body

[anikmankar]

noticed that the carb in take side has black soot like lining. this is there on all the carbs. The sparkplugs are nice and light tan color. no issues on starting or overheating.

any ideas ? could the valve setting be off. I had done valve setting about 3 months ago (150miles)

Thanks for your feedback

[Suzuki mad]

noticed that the carb in take side has black soot like lining. this is there on all the carbs. The sparkplugs are nice and light tan color. no issues on starting or overheating.

any ideas ? could the valve setting be off. I had done valve setting about 3 months ago (150miles)

Thanks for your feedback

Unlikely to be just one valve setting being off as that would mean that the cam timing would be out.

Maybe a valve not seating quite right or the gap is set on the large open side.

Suzuki mad

[anikmankar]

timiing ?

could the timing be off ?

will try and post a pic soon

[tkent02]

noticed that the carb in take side has black soot like lining. this is there on all the carbs. The sparkplugs are nice and light tan color. no issues on starting or overheating.

any ideas ? could the valve setting be off. I had done valve setting about 3 months ago (150miles)

Thanks for your feedback

Backfiring, could be caused by...
ignition timing way off...
burrnt valves but unlikely to be all four...
Could be the intake valves were so tight they were not closing at all, this would have been fixed when the valves were adjusted.
Cam timing way off?
Could be other reasons I'm not thinking of...

If it starts and runs correctly, and is not backfiring now, I would say whatever problem caused the backfiring has been fixed, whoever fixed it just didn't clean up all the soot.

[anikmankar]

no backfire

no backfiring, no issues starting cold or warm. Timing too i had checked a month ago...not much to adjust as no points.

[tkent02]

no backfiring, no issues starting cold or warm. Timing too i had checked a month ago...not much to adjust as no points.

It must have been backfiring at one time, sounds like it's not a problem anymore. (:-[)

[BentRod]

a compression test would tell if you have valve problems that might cause soot that far back. and your bike would run terribly if it was a backfiring issue

when was the last time the carbs were cleaned? and how often do you clean your air filter and re oil it?

[anikmankar]

carb cleaning

Carb cleaning was done about 3 months ago

Airfilter is new - K&N type (no oiling required), with V&H 1-to-4

Float levels ok.

[Zook]

Since it is on the intake side it is probably from the crankcase breather tube. Oil vapors from blow by are returned to the breather box to be burned by the engine.

[anikmankar]

breather...

would that send the fumes to the airbox right ? then i should have soot at the airfilter end. unless i got this all reversed

[Macmatic]

Carb cleaning was done about 3 months ago

Airfilter is new - K&N type (no oiling required), with V&H 1-to-4

Float levels ok.

Are you sure about the filter? The only K&N type I'm familiar with require oiling with the proper type of oil.

/\/\ac

[anikmankar]

air filter

yeah - pretty sure - its not original K&N but similar type- checked with the manufacturer...no need of oil.

Posted a picture

[49er]

It has probably had tuning issues in the past, like tight valve clearances.
It's obviously running good now. Just ride it.
When you can't overcome the guilt any longer, pull the carbs and clean the carbon off them. Next winter?

[Zook]

would that send the fumes to the airbox right ? then i should have soot at the airfilter end. unless i got this all reversed

Ahh...when you said intake side I thought you meant on the IN take side. I couldn't open the thumbnail.