1978 Merc 90 Timing issue

[cbcmarine]

So I had to replace the trigger, that did not go so bad as I thought, got it all back together and I have spark and have adjusted the timing as per the merc manual. The single dot lines up with the arrow. It will fire but not run ?? I tried moving it back counterclockwise as manual states ??

Help anyone ?
Ideas for this tower of power?

 

[Chris1956]

Re: 1978 Merc 90 Timing issue

OK, A Merc of that vintage will have an adjustable timing pointer. Use a dial indicator, ruler or caliper to set the motor to .464" BTDC, and adjust the timing pointer to indicate such. Now rotate the flywheel until the cast arrow on the distributor pully points to the punch mark on the timing decal. Remove timing belt and adjust flywheel to point to TDC, and reinstall belt. if she still won't fire, inspect spark plug wires for arcing. What is the conditon of the rotor? The carbon electrode in the dist. cap?

 

[cbcmarine]

Re: 1978 Merc 90 Timing issue

Thanks I did get it to fire now I will adjust timing and see how that goes. The rotor seems fine and I replaced the carbon electrode in the distributor cap when I did the trigger.

It seems fairly simple but older motors never are !!