should i convert my 91- 5.7L ski mercruiser to electronic ignition?

[ChrisDinCA]

i'm considering converting to electronic ignition to help resolve hard starting issues when engine is hot. (i'm also looking at a 3 base gasket system with heat shield but may that should be another post.)
i've read much about vapor locking, not sure i'm having that issue or not, but there are times when i have to crank the engine a good 6-8 seconds with wot, before it will fire. it acts flooded, because when it finally turns over, it's black smoke and choking before it clears out.. carb is not leaking at pump, no evidence of fuel drips and choke is wide open.. other than that, it runs great.. never ever has a problem starting when cold.
have never checked the dwell, just timing and point gap setting...so maybe i should start there.
i'm wondering if e-ignition would be hotter and give a more reliable start... every time.
engine has 900+hours.. original. i've also read about possible timing chain stretch causing the timing to advance when hot..
so i'd like to hear all the opinions on all this...

lett'm fly..
thanks.

 

[Bt Doctur]

A `91 should be electronic ign already unless somebody removed it.Carbs dont readily have a vapor lock issue
Black smoke at a restart is a sign of a leaking carb A very,very loose timing chain will retard the timing. A test for that is remove the spark plugs, and rotate the motor until the timing tab is at 0. remove the dist cap and mark the rotor. Now turn the engine backwards until the rotor moves, look at the timing mark location Should be less that 2 degrees

 

[ChrisDinCA]

unfortunately, it is not. It has a mallory ignition with points and distributor, original oem. thanks for the timing belt check tip...very useful.
so, leaking carb would be due to high float, or boil over during heat soak after shut down?.. will the 3 piece base gasket w/ heat shield help prevent this? carb is 4bbl qjet that has been professionally rebuilt and vacuum tested a couple years back.

keep comments comming.
has anyone converted their ignition to electronic?..

 

[Bt Doctur]

the welch plugs in the base tend to leak gas ,this could be where your problem lies with restarts

 

[Bt Doctur]

http://www.hotrod.com/articles/hppp-1107-home-remedy-quadrajet-carburetor/

 

[Scott Danforth]

I would leave the points myself.

I would also pull the carb and fix the welsh plugs.

 

[Lou C]

As long as you can get parts for the points distributor and it is set up right for the engine (ie mechanical advance, correct # of degrees at correct rpm) I would keep it. I still have one in my OMC Cobra. Very simple to maintain esp if you are over 60 years old and grew up when all our cars had points (except Chrysler products started with electronic in the early 70s).

 

[Bondo]

i'm considering converting to electronic ignition

Ayuh,....... Welcome Aboard,...... I completely agree, ya got a Carb problem,.....

'n I too, can't believe a '91 350 has a points ignition,.....

But, if ya wanta blow the funds, the Delco Voyager is a decent system, at a fair price,.....

 

[ChrisDinCA]

thanks all. points it is and will be
i'm not looking to spend money for the sake of it.. ya'll already know what "boat" stands for!
i'll look at the welsh plugs, but i'm wondering if i can just remove the old epoxy and refinish with new?
what type of epoxy should be used for this?
i'm not really interested in completely dismantling that carb.. again.. tapping holes, etc.. as the article shows, seems i should get a solid fix with new epoxy. i mean the original lasted this long!..

 

[achris]

Check out Quadradjet parts website. They have 'O' ringed welch plugs. If yours are leaking, that's the way I would go. On the points ignition, Merc used electronic from 1984 on... If you have points, then either your engine is not 1991, or someone's done a butcher job. Do you have an engine serial number handy?

Chris.......

 

[ChrisDinCA]

MIE 5.7L Competition Ski engine.
Serial number: D399882L
for some reason, points are oem for this engine I have the Mercruiser Service Manual, number 15, which has been extremely helpful throughout the years, for sure... you learn something new everyday- eh!..
no hack jobs have been done on this engine.. you can eat off it!

 

[muc]

I agree most common cause is the quadrajet. But it is still a good idea to hook up a dwell meter, they are much more accurate than gapping the points. For every degree dwell is off timing will be off the same. While dwell meter is hooked up --- rev the engine, if dwell changes, the distributor is worn out.