Does this xr100 spark plug look ok?

[Refresh]

 

 

Its bone stock jetting with tb120 kit stock exhaust. 15.4 hrs on 120kit and plug. Thinking of going to 100 main.

[Woodspike]

Just from the pic, with no further details I would say it is okay. A little bit lean maybe. 

The question is when did you pull the plug to check it. After a full day of riding just to see? That does not really tell you anything meaningful. 

If you rode at a specific throttle setting, cut the motor and then pulled the plug for a reading that would show you specific jetting results for that part of the puzzle. 

The black around the outside edge says that the first option is more likely. 

[CEEZ]

These little bikes come jetted LEAN from the factory, to meet emissions.  It is always a good idea to go up 1 or 2 main jet sizes and experiment with 1 size up on the pilot jet.  that is what I do with all my NEW bikes & ATVs ?.

[Old School Al]

1 hour ago, CEEZ said:

These little bikes come jetted LEAN from the factory, to meet emissions.  It is always a good idea to go up 1 or 2 main jet sizes and experiment with 1 size up on the pilot jet.  that is what I do with all my NEW bikes & ATVs ?.

Strange...........my 200's and 100 run better with the stock jets!  

Old School Al

[CEEZ]

You must be high[emoji3]... altitude that is...

[Refresh]

Just looking for opinions. It runs great and spends most of its life rode hard by a 200lb guy. Around 1000ft above sea level