Freestyle Reading (Tuning) spark plugs-

[dcptr]

So I've just about finished tuning my freestyle setup, matched the carbs (needle wise) and have come out fairly different.
Front plug came out with the prong/tip white- which I richened up slightly- now comes out copper coloured.

The rear cylinder plug is comming out dry-black tip with carbon deposits- even when the front cylinder was too rich, it didn't do this. Is the rear still too rich or is the carbon build-up from higher cylinder temperature?

 

[kevbo]

Open the rear to match the front and install new plugs. Check them after every ride for comparison. Freestyle tunes tend to be rich at part throttle and most of the riding is done in this range. This means plugs get darker than they would in something that gets more full throttle time. This also makes plug reading less accurate because you can have dark plugs and still toast a cylinder on a random full throttle run.

 

[dcptr]

Thanks dude, so is the black, carbon buildup due to being lean?

 

[camojoe]

That plug is what you want the other to look like. Turn out your rear carb quarter turn and check again. A dark caramel color is what I go for

 

[kevbo]

Thanks dude, so is the black, carbon buildup due to being lean?

I have found that very rich mixtures make pistons clean and plugs dirty. Hot mixtures do the opposite.