120Hp Timing Way Off

[ThomasHill]

I'm giving my 120 Hp Mercruiser a tune up. Got new points, plugs, rotor and cap on. Reset the idle and then checked the timing. Man, it is way off. Specs call for 8 BTC and the timing marks are an inch and a half away from the gauge. Went to loosen the bolt securing the Distributor and can't get a socket or a wrench in there. The wrench just dosen't have enough room the turn with the fuel pump and Dist Shaft stopping it. So what tool is used to loosen this bold so you can set timing?
Jack

 

[bigbob_FTW]

Re: 120Hp Timing Way Off

they make a special wrench for the distributor bolt. It's C shaped so it will reach. any auto store should have one.

 

[thannah84]

Re: 120Hp Timing Way Off

Thom......What year is your 120??? Mine is an 84' and it is 4*BTDC...

 

[bigbob_FTW]

Re: 120Hp Timing Way Off

My '84 is 8 deg as well.

 

[ThomasHill]

Re: 120Hp Timing Way Off

Got a wrench and reset the timing. What a difference. Had to readjust the idle as well. I think that whoever had this boat before used the timing to keep the engine running at no throttle. The idle adjusting screw wasn't in contact with the throttle plate at all. I checked the specs again and it does call for 8 BTC. And mine is a 77.

 

[bigbob_FTW]

Re: 120Hp Timing Way Off

sounds like you got it just right, sweet isn't it?