Anyone know what might cause one cylinder to be significantly higher than the others? I was looking for a low cylinder, and this is what I found:
Cylinders 1,2,3,and 6 are all 170 PSI.
Cylinder 4 is 181 PSI, and #5 is 175 PSI.
Could this be the cause of any problems I'm having - such as lack of power, and rough running engine despite being perfectly timed? Or is this difference in PSI insignificant?
That sounds high all the way across actually. How many miles on the motor. Excessive carbon buildup may be a possibility? Have you done a leakdown, that will give a better indication of the true condition of the motor.