Black, oily (?), plug.

[skids]

all within 10%

I gotta say, and I am just putting this out there... It is possible to find even wear, have compression within 10% of each other (from the average?) and be on the low side of "good." I know that there are some differences in the average reading from one gage to another due to calibration drift, and some differences due to initial ambient air density from sea level to a mile high. It is possible to have say, 115 psi average +/- 5% from highest to lowest, and not have the hp that it should. With the same gage and another bike, I have 150 psi avg and you definately can feel it on the high end.

Originally posted by DiverRay
Check ALL FOUR and keep in mind anything over 10% in difference IS a problem.

[birch]

This is probably not the best answer, but it worked for me. I simply started running a higher octane fuel. I won't run nothing lower than 92 octane, and my plugs do not load up anymore. I know that it is a simple synchro. problem, but it runs fine and runs smooth throughout the torque/horsepower range as long as I run the expensive stuff through her. Sometime, I may create the homemade synchronizer and fix the issue, but It no longer bothers me.

My bike is jetted and has a kerker four into one. I read somewhere that the kerker exhaust somehow allows the plugs to load up somewhat at an idle. This is certainly the case for my 78. It will idle fine for about five minutes and then it will start to snap, crackle, and pop. A simple crack of the throttle and she cleans right out.

Casey B.