How do these two relate? What if one reads rich and the other lean?
Piston wash vs. spark plug reading
- Thread starter Henry Stephen
- Start date
They are opposite of each other. Cool temps make the plugs dark and the pistons clean or with a wet greasy residue. High temps make plugs clean but leave a dark crusty spot on the piston. You should not be looking at these for tuning. This is because they are lagging indicators that can change with the way you ride. For instance, a good freestyle tune will be very rich at part throttle and peaked out at full throttle. For most freestyle/surf riders, plugs and piston will appear way too rich but may melt under sustained full throttle. Someone that likes to run down a river would want a leaner part throttle for range, and richer full throttle for safety. Start out rich and slowly lean it in, this will save a piston and give you time to learn how your carbs react to changes.
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Exactly ^
I ride my normal way and tune for piston wash. Should have clean spots around the intake ports with the rest having a carbon coating. buy a bore scope to check it easy. Plugs are a good backup if you cant see in the bore or remove the head often. Go for a toasted marshmallow color. Always stay richer than you think you should be, you wont blow a motor from too much fuel.
I ride my normal way and tune for piston wash. Should have clean spots around the intake ports with the rest having a carbon coating. buy a bore scope to check it easy. Plugs are a good backup if you cant see in the bore or remove the head often. Go for a toasted marshmallow color. Always stay richer than you think you should be, you wont blow a motor from too much fuel.
DAG
Yes, my balls tickled from that landing
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- Charlotte, NC