Re: Grey Spark Plug Scum
What is important is the specification in your 1975 135HP OMC service manual: Specifications page 2-2: "Timing ..............20? @ 4300-4600 RPM, in gear"
That setting was generally, and ideally, made in a test tank, using a test wheel.
You can't do anything with that 20? setting without first checking the timing pointer to be sure that it is exact.
I believe that Mr Reeves did mean for his method to be used with your engine and that the 4 degree setting is correct. It is also important to take nothing out of context, which I believe is why he adds these words:
"If you set the engine to its true setting at cranking speed, when running it will advance beyond its limit by 4? which will set up pre-ignition causing guaranteed piston damage! You don't want that to take place."
http://forums.iboats.com/showthread.php?t=228183
I would certainly recommend that you correspond directly with Mr. Reeves if you have any doubt. By clicking on his user name you will get the link for a PM (personal message).
In the meantime see entry #16 in the following thread:
http://forums.iboats.com/showthread.php?t=176669&highlight=WOT+Timing
What is important is the specification in your 1975 135HP OMC service manual: Specifications page 2-2: "Timing ..............20? @ 4300-4600 RPM, in gear"
That setting was generally, and ideally, made in a test tank, using a test wheel.
You can't do anything with that 20? setting without first checking the timing pointer to be sure that it is exact.
I believe that Mr Reeves did mean for his method to be used with your engine and that the 4 degree setting is correct. It is also important to take nothing out of context, which I believe is why he adds these words:
"If you set the engine to its true setting at cranking speed, when running it will advance beyond its limit by 4? which will set up pre-ignition causing guaranteed piston damage! You don't want that to take place."
http://forums.iboats.com/showthread.php?t=228183
I would certainly recommend that you correspond directly with Mr. Reeves if you have any doubt. By clicking on his user name you will get the link for a PM (personal message).
In the meantime see entry #16 in the following thread:
http://forums.iboats.com/showthread.php?t=176669&highlight=WOT+Timing