Spark Plugs Carbon

[Yatez]

My bike recently had a rebuilt engine and runs awesome, however the spark plugs are baddly covered with carbon after a few rides on the bike. Once a replace or clean the plugs it runs great again... How can I correct this issue?

 

[Paulrxs650]

Have you got a picture of the plugs?
Could be one of two things:

1. Oil fouling
2. Carbs running too rich

Whats your MPG like
Are you topping up with oil?

 

[Yatez]

Attached is a picture of the spark plug....

Im not too sure what my MPG is, the bike a 1977 so im not sure how to determine. I have been filliing the fuel tank with the high end gas - such 91, or shell V power.

The oil levels are good - I use Catrol 4 stroke 10W-40

Thanks

 

[wherearewe]

Welcome to the site. Sooty black deposits usually mean too rich. Hard shiny or oily looking one's indicate oil fouling. So, the carbs. What type are they? Jetting? Setup of mix screw and float height etc? Exhaust and air filter type? Give us a bit more info and perhaps we can help. There are a lot of threads with similar issues. Have you read the carb guide?

 

[Yatez]

They buld up is sooty black, so i would say too rich... Here is a picture of one of the carbs. The exhuast is short pipes, they have been on the bike for years. I bet the carbs need to be adjusted just no idea how/

 

[angus67]

carb guide
http://www.xs650.com/forum/showthread.php?t=43

 

[wherearewe]

Yes read the carb guide. Then read it again. Once you think you know it all, have another skim, then open up your carbs to take a look. How long have you had the bike?

 

[Paulrxs650]

+1 on the carb guide - excellent

 

[Grinder]

Try autolite 63 plugs. My plugs in my 77 looked like yours and changing to these plugs made for a much better color without changing anything.