77 Evinrude timing problem

Hey guys been reading a lot on here and trying to figure out whats up with this 77 55hp evinrude. Spark is good, compression is 150 on both cylinders. It seems like the timing is moving on me. I've had it running on the muffs a couple times but when I take it on the water it would run good for a couple miles then very little to zero power. This was after setting the timing to 4 degrees. I had to change the synch and link a lot to get it to 4 (screw backed almost all the way out. Right now after my 2nd loss of power I pulled the flywheel to check the keyway and it is not sheared and seems o.k. but when checking the rotation when #1 is at tdc the timing numbers are 180 degrees off from the marker. Did something get off somewhere else? Thanks so much for any advice.

Actually the timing on these motors is set at the factory and usually does not require adjusting for the life of the motor !!!----------The 4 degrees is what is called the " throttle pick-up timing " and it is not to be confused with " full advance timing "-----------I think you need to review timing adjustments in the manual.-----Do this before you risk serious damage to your motor !

racerone said:

Actually the timing on these motors is set at the factory and usually does not require adjusting for the life of the motor !!!----------The 4 degrees is what is called the " throttle pick-up timing " and it is not to be confused with " full advance timing "-----------I think you need to review timing adjustments in the manual.-----Do this before you risk serious damage to your motor !

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When I got this boat the timing and link-synch had already been jacked around. I bought a service manual and have set it(with a timing light) so the motor was starting and running fairly well but the timing does not stay at 4 degrees at pick up. Correct me if I'm wrong but shouldn't the timing marks be fairly close when the #1 piston is rotated to TDC?

The screw with the black rubber bumper is the maximum full throttle timing advance.-----------Make sure it is set correctly.-------The throttle pickup is at 4 degrees.------------At idle the throttle plates must be closed !-----motor idle speed is then controlled by retarding the timing more.------If it idles well with ignition retarted more ----" you have a good motor "--------------There must be a reason why someone started adjusting the timing !