tune up

[Jcris]

I've got a !996 4.3 l LX Mercruiser. I've noticed it seemed a bit sluggish when starting so after inspection I replaced plugs and the distributor rotor and cap. The old ones looked worn so I figured I might as well start fresh with some new ignition components. After this work I found the timing was a bit advanced as well as the idle rpm. So I adjusted the timing to 8 degrees BTDC and the idle to 650 per manufacturer spec. I did these adjustments after the motor was up to normal operating temp. Specifically 160-170 water temp. Took it out this morning and the sluggish starting has not gone away and now it seems to run on a bit after I shut it down. It seems I've gone the wrong direction. This is a 2 barrel carb and it has been quite awhile since I've wrenched on anything carbureted. The starting battery is older (2009) but holds a decent charge (12.8 vdc). I'd like some advise on where to go from here.
Thanks,
Jcris

 

[alldodge]

Your 96 should probably have the TB-V ignition, and 10 BTDC would be correct if that is what you have. If this is the case did you ground the Purple/White wire when setting the timing?

 

[Jcris]

This is a TB 4
Jcris

 

[alldodge]

This is a TB 4
Jcris

In that case, according to manual 18 you should set timing at 8 BTDC

 

[Jcris]

Thanks AllDodge,
I'm going to recheck the timing this afternoon

 

[Bondo]

and now it seems to run on a bit after I shut it down.

Ayuh,..... Don't let it do that, turn the key back On,....

The last studder/ shutter ya hear from a dieselin' gas motor is it runnin', Backwards,....
It'll suck in water, 'n hydro-lock,...

I didn't see fuel filters mentioned in yer tune-up,....
If the timin' in dead-on, check to see if the carb is dribblin' gas down the venturi,.... as in leakin',...

Heat also plays a role in dieselin',.... let it idle a minute or so, 'n see if that helps,...

 

[Jcris]

Hey all dodge,
Turns out this motor does have the TB 5 ignition. I retimed to 10 BTDC at 650 rpm idle, purple/white grounded.
What can I say, learning curve still exists for this old man
Jcris