Mercruiser 140 points to electronic ignition

[DJ]

Re: Mercruiser 140 points to electronic ignition

only 2 things lazier than me, fish and lectricity.
its why I understand them .
if the conditions require 5Kv to arc the plug gap thats all you will ever see, regaurdless.
as the parts age occasionally you will see secondary voltages of maybe 12 KV on that 140.
point type systems generally are comfortable with up to 20-25 KV.

.

Correct. More volts in does NOT mean more out. You only get enough to jump the gap.

 

[Robj]

Re: Mercruiser 140 points to electronic ignition

Correct. But more volts mean you can have a bigger gap and stronger spark. Which is why I will be increasing my spark plug gap to .035 to take advantage of the stronger spark. Many of you guys knock the cost of these systems, so far I have saved on two sets of points with condensors and a ballast resistor. If I include the fact that I would have had to buy a dwell meter to set my old points, the Pertronix system has saved me $$.

Have a great day,

Rob.

 

[rodbolt]

Re: Mercruiser 140 points to electronic ignition

I have been toying with using the coil in cap style ign used on the F250 and F350 yamahas,
the have a Zener diode setup that starts the arc at 32 Kv.
it would have to be triggered with a 5v point set up. grind 2 lobes of the point cam and trigger 1-4 then 2-3 .
but at almost 200 each I will have to wait. that and a carbed motor simply doesnt need it.

 

[whs109]

Re: Mercruiser 140 points to electronic ignition

Thanks to all who recommended the Pertronix kit. Just bought an '86 Celebrity with the 3.0L Mercruiser and decided to upgrade. I ran into a small issue during installation which others might also run across. The hall-effect coil which inserts down over the distributor shaft seems like it is seated properly when it really needs to move down 3/16" further until the lip of the top of the coil joins the reduced diameter slot of the distributor shaft.

I installed the kit, figured the coil was seated all the way around, and installed the rotor. Started the engine but spun the rotor since the key was not sitting all the way down on the shaft causing the engine not to start. Bought a new rotor and cap, removed 1/4" off of the bottom of my rotor to ensure the keyway would fit, but the engine ran very rough. With a timing light, I noticed that the #1 cylinder spark was sporatic. I had purchased a second Pertronix kit as a back-up and tried that one...now cylinders 1, 2, & 4 fired as expected, but I could not get cylinder #3 to fire. I tried swapping spark plug cables and spark plug from #3 to #4, but still had no spark on cylinder #3.

So I wrote to Pertronix...they told me that I probably did not have the hall-effect coil seated all the way and that I should not have needed to remove any material from the bottom of the rotor. They suggested taking a deep socket and a hammer and tapping the coil down further until the lip seats in the groove of the distributor shaft. I did this, it took the hall-effect coil down another 3/16" and the engine started like a champ!

When the hall-effect coil is correctly installed, it appears to sit lower than expected when comparing to the height of the module...this is apparently normal!

I have attached a few pictures to illustrate...first two are wrong installation with the hall-effect coil being too high, second two are correct hall-effect coil installation.

 

[windsors03cobra]

Re: Mercruiser 140 points to electronic ignition

Only thing wrong with points is the fact they cost $16 now, I remember when they were a quarter........

 

[SSTKO81]

Re: Bringin it up a year later

Re: Bringin it up a year later

Hello all. I've been trying to follow this post but got a little lost in the tech talk. I've go a problem with my new conversion. Yea, it took 15 minutes to hook up but now it seems I only have spart to my #3 cylinder. Why? The wires, coil, cap, rotor, and plugs are either new or in good shape. I've got rythmic spark from the coil, so I know that much is good. And the rotor is spinning while cranking, so now what? what's left?
I thought maybe the mag trigger wasn't down on the dist. shaft well so I tapped it down a little. -no better.
Timing? -who knows? I cant start it to check the timing.
I'm at my wits' end

 

[antsmands]

Re: Bringin it up a year later

Re: Bringin it up a year later

How was your boat running before the conversion. When I did my conversion it ran better but I still need to rebuilt my carb before it would start right up. Now with the electronic points and rebuilt carb it runs great!

 

[SSTKO81]

Re: Mercruiser 140 points to electronic ignition

Before it ran just ok. It was hard to get started and would sometimes (for no reason) just die at full throttle in the middle of the lake. I think that was caused by a bad coil, which has since been replaced. I rebuilt the carb too, but I wont really know how that went till I at least get spark to all cylinders.