86 mercury 8hp sailmate - flywheel timing marks

[toliver66]

Can anyone identify these timing marks. I believe the single dot is tdc and the 2 dots are 6 degrees btdc and the three dots are 36 degrees btdc. The service manual doesnt show these markings.

 

[toliver66]

Any body?

 

[Mohawkmtrs]

I also looked in the manual and you're right...it doesn't show these dots.
I agree with your logic because max WOT timing is 36 degrees BTDC but idle timing is 8* BTDC.

One way to check is to scribe/draw lines from the single dot and three dot positions to the top of the flywheel edge then to the center of the flywheel and measure this angle with a protractor from your kid's math kit.

 

[Mohawkmtrs]

Thinking it over, the angle (if 36 degrees) only measures from the single dot to the three dot position and not necessarily from TDC.

To determine TDC, remove top spark plug, line up the single dot with the timing indicator, insert a screwdriver, dowel, etc. into #1 plug hole and rotate the flywheel back and forth while watching the screwdriver go up and down.

Screwdriver max up indicates TDC and single dot should line up with the timing indicator.

 

[Mohawkmtrs]

...well !!?