Posts: 107
Location: milwaukee | FWIW I would have agreed with the opinions on the compression readings until I ran across this in a service manual for my motor:
"In order to maintain proper cylinder temperature on 3-cylinder and V6 engines, Yamaha varies the cylinder head volume on some models. A V6 will normally show the highest compression on cylinders 1 and 2 with cylinders 5 and 6 showing the lowest reading..."
It goes on to say that "A variation of of more than 15 psi between two cylinders indicates a problem...".
I didn't see any mention of the motor brand. The 105-120 variance on that motor may well be within spec if its a Yamaha. Not perfect, but still within spec. |
