How to set point gap ?? 4.3 mercrusier

[al0311]

Hi guys so I’m having trouble setting the point gap. Long story short I hope determined my not start issue is related to my points being worn and rusted. Since then I have cleaned to plate and installed new condenser and points. The problem I’m having is adjusting the gap. I think from what I was able to find online the gap is supposed to be 0.19???
but I can’t get the points apart and fixed to that gap. Any suggestions ? Also is that the recommended gap ?
Its a 1990 4.3 mercrusier.
Btw when I pulled it out originally that was how the points were set then in the distributor.
Thanks

 

[Bondo]

Ayuh,..... Ya gotta put the plate back into the distributor, rotate the motor, so a hi-point of the distributor cam holds the points open, 'n adjust the ground side to yer .019",.....

.016" to .019" is 'bout right, but there is no spec for a 1990 Merc 4.3l, because they'd all gone to T-Bolt electronic ignition, Years before,....

 

[Bondo]

This thread will give ya some insight on what yer doin',.....

 

[ziggy]

i don't know what service manual ya use, but i looked up point gap and dwell in s/m #7. don't know if it cover yer engine or not. but it says gap is .020'' and dwell is 34*-38*. (ya need to find which manual to use for yer engine and be sure the specs ya use are for your engine as my example may be the wrong specs)
i set points on my old 165 every spring. i don't set them to the inch gap spec. i set it as to the dwell spec. with a dwell meter. these two specs are the same, just two ways of stating the spec.
so, get yer dwell meter out. i ground out my coil and put water to the drive even though it won't start with the coil tower wire removed. then w/ a remote starter switch i can crank my engine from the engine. not the helm. while i crank the engine over i adj. my points to the specified value. i leave enough friction on the points that they'll stay in place, but also allow me to move them slightly. so one hand on the start switch, one hand to adj. the points to spec. when i get them where i want them. i tighten the lock down screw for the points and recheck to be sure it's where i want them. if not where i want them. i go and readj. again till i get it right. when there right. i put the grease on the cam that comes with the points and move on to timing.
do point gap/dwell 1st, then do timing. as dwell affects timing. so time it last.
hope this helps. it works for me every time i set them. it's a pretty fast process.

 

[kenny nunez]

Good point ZIGGY. When I had my shop I would set the dwell with the plugs out and also the coil grounded, then put the plugs on the wires and ground them , then spin the engine and set the timing. A little more time consuming but worth the results. This helps if there is a carberator/ idle problem and eliminates the centrifugal advance from interfering with the base timing.

 

[achris]

Not sure what's going on with your engine, but mercruiser 4.3s NEVER had points. The engine was introduced in 1984 with TB-IV, fully electronic ignition. If you have a points distributor, then it's either not a mercruiser or it's not a 1990 4.3 (the 3.8 had points), or someone has dropped a 3.8 dist in.

Chris. ....

 

[Bondo]

Not sure what's going on with your engine, but mercruiser 4.3s NEVER had points. The engine was introduced in 1984 with TB-IV, fully electronic ignition. If you have a points distributor, then it's either not a mercruiser or it's not a 1990 4.3 (the 3.8 had points), or someone has dropped a 3.8 dist in.

Chris. ....

Ayuh,..... Or an OMC distributor,.....

 

[al0311]

Hey guys I apperciate all your feedbacks. So I got it all back together set the gap the whole nine yards. Go to turn it over and still no start. I hook up my spark tester and the spark plugs are still not getting spark ????? I’m at a lose at this point bout to take it to the boat mechanics

 

[Bondo]

Ayuh,.... With the cap off, the key on, is there spark at the points,..??

 

[al0311]

I’ll check first thing tommorow and report back

 

[al0311]

When I took the cap off again after this. The points were closed should they be closed when the motor is completely off ?

 

[al0311]

Also when you say key on am I just turning the key on and off ? Not cranking

 

[Bt Doctur]

OK, you are not too familiar with this type of system so.....................
let me get a link for you

 

[Bt Doctur]

https://www.youtube.com/watch?v=W94iksaQwUo

 

[Bt Doctur]

https://www.youtube.com/watch?v=Y9wZvcr3v2c

 

[al0311]

Forgot to mention in my post that the coil gets very warm to touch wondering if this might Have something to do with it ?

 

[Bt Doctur]

Have never seen a points plate like that before so I`m thinking it`s a hack job conversion . Can you post some pics of the dist body.

 

[al0311]

Yeah I can tommorow

 

[Lou C]

It does look somewhat like the Prestolite on my '88 OMC 4.3 which has points.

 

[al0311]

Looking at the new points I don’t have that copper plate coming out. Is that necessary ?