Breakerless Ignition Conversion - gizmo fell apart



A good example of leave well enough alone, which I rarely do. The boat ('87 Ski Boat with typical inboard direct drive 351 cu. in. Ford block Pleasurecraft marine engine) was running poorly after just replacing the transmission (ouch!). I just spent a bunch of money and I want it running perfect. I figured it was time for a new distributor cap and rotor. I pulled the cap and pulled the rotor and some pieces came apart in my hand. About 8 years ago the distributor was converted from points to a breakerless set up and the gizmo that rides on the cam, just under the rotor had all come unglued and fell apart.

Inside this “gizmo” are 8 little magnets, 4 of which stayed in place, the other 4 tumbled out. I found 2 of the magnets stuck to other magnets, and eventually found all eight. Without glue it was very hard to get the magnets back in place and put the gizmo back together, magnets tend to stick to one another and these little guys are pretty strong. Eventually I got it back together. Put the old rotor and cap back on and got the boat running, but of course now it runs worse, went from poor to really rough.

My brother (electrical engineer, and good boat tinkerer mechanic) feels the magnet polarity is important. The 4 magnets that jumped out got put back in place, but it was tough enough without trying to figure out polarity.

My question, is the polarity important? Meaning do I have to take the gizmo apart, and try to determine the polarity of the each little magnet and reassemble? It is going to be a “bench” job this time if I do it. I think there is some glue residue on at least a few of the magnets that will aid me in properly replacing them. Perhaps with some tweezers I can figure the polarity on the others. Could be a lot of time for no big benefit.

I have ordered a new breakerless system to replace the whole thing, but won’t have it for a few days and every day on the water now is critical, it is getting cool here in PA. So, is the polarity important and should I try to “rebuild” the gizmo or not?


I wonder if a distributor from a 1980s 5.0L Ford car would drop in?

Take your distributor to a junkyard and compare.


I think that it would. That’s exactly what I did to convert a 73 (400) to electronic ignition. The conversion was very reliable. I also changed the distributor cap and wires to the big blue two piece cap and high voltage wires.


Thanks circutsmith and tardis. A new or another distributor might be necessary. Marine motors of that era didn’t have vacuum advances, simply centrifical. My timing light was junk (hadn’t used it in years) so I bought a new one to see if the timing advances when I blip the throttle, as it should. If not, I definately will need to consider a new distributor, but I’m not sure one from a car would be compatible.

Noone seems to have an opinion on the little magnets. I got a new cap and rotor and I guess I’ll try playing with the magnet thing to see if I can get it right. Then with the new parts installed I can time it properly and see how it runs.

I replaced the Holly 4 bbl carb two summers ago and hopefully the carb is still ok. No black exhaust smoke pouring out like the old carb it replaced. It just seems to take too much cranking to get it to fire up and I need to get the idle smoother at 700 rpm to reduce stress on my new trans.

I’ll be fiddling with it all afternoon.