My 02 prosport is running darker..richer looking plugs than it used to

Now it loads up at stop lights, have to keep reving to clear rough idle. And when I got to destination and restarted it backfired.. through the carb I think. Maybe a new coil would help..?

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DynoDave

Active Member
Sounds like a carb adjustment issue. I would clean and re-adjust carb, and make sure the air filter is clean first.
 

Sven

Well-Known Member
Now it loads up at stop lights, have to keep reving to clear rough idle.
COMPRESSION: King of the tail chasers. So before throwing parts at it, before removing half the parts off the bike, before you go any further, here is where you are at.

... restarted it backfired.. through the carb...
FUEL: It runs so fat, it might be pouring gas in there due to a carb problem.

Maybe a new coil would help..?
SPARK: Sometimes that does help... when the other two are out of the way.
 
So, what I did was reduced the plug gap from.040 to .037 in case the coil is getting weak. I backed off on the accelerator pump about 10°. This solved the problem, temporary.. I'm gonna look for a new coil. Thanks guys for help.

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Butch Cassidy

Active Member
Supporting Member
I ride it every day or so. The gas is fresh

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...just because you just put gas in it doesn't mean it is any good. Water is heavier than gas, so when you fill up if the gas has water it will be almost immediately known. If it is bad, you will have to drop the float bowl and drain the gas... then re-check for more water before you tighten it back down.
 

DynoDave

Active Member
I replaced my stock coil with a Vodoo coil. Runs great and seems to start easier.
 

Sven

Well-Known Member
Sooty plugs:
1. Lose jets, falling out jets. Loose the gas gets sucked up the threads. Falling out, real rich if not stalling.
2. High float level, meaning, gas is higher in the bowl so it heads up the main with a lot more gas up the jet tube.
3. Retard ign. where it would light off too late and have the pipe fire it when it leaves the exhaust, or when valve overlap occurs and the flame front heads out the carb still burning late via retard.
4. Low compression is to get that out of the way so spark and fuel is more narrowed down.
 
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