1988 20hp Mercury Timing problem

Looking for the correct idle speed timing degree setting for this motor. I can't find a specific reference to this particular year but see several differing setting for years right before and right after this model year.

more facts below:

1988 (#0B269663) 20hp Merc outboard - manual - short shaft.
The carburetor is a WMC type. I think the fact that it has a WMC carb is important but it makes the motor a bit odd in the Repair manual I have used. I would not be surprised if mercury had a service bulletin on this.


One source says 2 deg BTDC for idle timing
Another source says 2 deg ATDC for idle timing
Other manuals that don't specify the exact year give me other settings.

Does anyone know for sure what the timing is for this year (1988) motor ?

Thanks so much if you can give me the info !

Re: 1988 20hp Mercury Timing problem

primary pick up is set to 2 deg atdc which is the next mark to the rigth of the dot on flywheel .

then the max timing is 25 deg btdc

just top be sure - you are aware there are 2 timing settings to be made right ?

Re: 1988 20hp Mercury Timing problem

verado7 said:

primary pick up is set to 2 deg atdc which is the next mark to the rigth of the dot on flywheel .

then the max timing is 25 deg btdc

just to be sure - you are aware there are 2 timing settings to be made right ?

Click to expand...

Yes. The manual is quite detailed as to the steps to go through. The more important Adj is probably the WOT timing setting. Thanks much for this info. Much appreciated.