timing 3.7 mercruiser

[trkr75]

Just did the conversion from a points system to the electric distributor system from pentronix. What would be a good spot to start with engine timing?

Thanks

Boat 1986 Sea Ray Sundancer 270
Engines (Twins) 3.7 Mercruiser
Out Drives Alpha I

 

[Bondo]

Re: timing 3.7 mercruiser

Ayuh,.... The Same spec as it's Always been set too....

 

[trkr75]

Re: timing 3.7 mercruiser

Well I guess if I was sure what it was I wouldn't have posted my question here.

 

[Bondo]

Re: timing 3.7 mercruiser

Well I guess if I was sure what it was I wouldn't have posted my question here.

Ayuh,... Sorry,... I think the 470s are timed to 6? BTC or so....(somebody will be along that Knows)

The way I read yer question, I thought, You thought it should be set to something other than the setting used with Points...

 

[guyaverage]

Re: timing 3.7 mercruiser

Thats the way I read it too....?

Anyway, the original spec was 8? BTDC, but Merc now recommends 4? BTDC.

Mine absolutely refuses to idle at anything less than 900 rpm on 4? BTDC, so good luck with getting the recommended 650-700 rpm idle with that.... Hopefully you carb is in better shape than mine.

 

[trkr75]

Re: timing 3.7 mercruiser

Thanks, it is idling around 800 now. I just wanted the correct spec so I would know if it was way off. Will check it out this weekend

 

[Don S]

Re: timing 3.7 mercruiser

4? BTDC at idle rpm 650-700 rpm is spec.

If you can't get it to run at those specs, you have problems other than timing.