Ignition timing marks mcm120 where?

[merc120_81]

I have 1981 Mercruiser 120 s/n 5828080.

I have found the timing scale mounted by the crank pully, but I see no harmonic balancer like on a car, and I can't seem to find any markings on the pully. I put a timing light on, and did not see any marking on the pully.

What is the "normal" mark on the pully, is there a notch, a line??

Engine is running decent now, but I want to replace the points and condenser as the boat is new to me, I have done the plugs rotor cap and wires.

Also, would poor spark/bad plug, contribute to overheating, I am still battling highspeed engine heat ups.

Thanks.
1981 Fourwins Marquis 170 Mercruiser 120

 

[Don S]

Re: Ignition timing marks mcm120 where?

The 120 don't have a vibration dampner, that's on the 140's.
There is a notch in the pulley. This picture should help you locate the mark in relation to the bolt holes.

 

[merc120_81]

Re: Ignition timing marks mcm120 where?

The 120 don't have a vibration dampner, that's on the 140's.
There is a notch in the pulley. This picture should help you locate the mark in relation to the bolt holes.

Thanks, hopefully nobody filled it with paint. I will take a look.

 

[Doernuth]

Re: Ignition timing marks mcm120 where?

When you find it fill it with a white grease pen. Makes it stand out under the timing light.