Aftermarket ignition

[pschauss]

I'm what appears to be an ignition problem with my starboard engine (again). Engine looses power and eventually stalls after running a while. I can restart after it cools down. As I described it in a previous post, my starboard engine has a Mallory distributor and my port engine, Prestolite. Both engines have the appropriate Sierra electronic ignition kit installed running with the coil recommended in the kit instructions. In the two seasons that I have been running the boat, I have replaced the ignition kit and coil on both engines.

Yesterday I replaced the coil on the starboard engine but the problem persists. I plan to replace the electronic ignition module tomorrow since I have spare.

Based on my last two seasons, I am reasonably confident that I can fix my ignition problem this time by replacing the unit in the distributor but it concerns me that these things keep failing. Would I be better off to replace both distributors with something like a Pertronix.

FWIW, I always carry a spare coil and electronic module for both distributors so that I will not get stranded if one of them fails.

[Tooeez]

Don't assume it's ignition just because it seems electrical. I had similar problems that I would have bet the farm had to be electrical in nature--turns out that alcohol laced poison they sell as gas up north had destroyed the fuel pumps.
Invest in the cheapest fuel pressure gauge you can find in an auto store, and make a temporary hook up between the pump and carb. It should be between 5-7 lbs.-- I had 2 lbs. on one engine, and less than 1 lb on the other, and they behaved just like you describe--run for a while, shut down randomly, start up again in a little bit.
Also check if you have anti-siphon valves at the fuel tank--they cause all sorts of headaches.
One last thought about electronic ignition--it's not the same as points. If you're old enough to remember point based systems it's easy to think the kind of problem you describe is electrical--it was common to have coils heat up and get erratic, condensers slowly fail, resistors go bad--a lot of it changing as the motor heated up and cooled down. It seems to me, based on my limited experience, that electronic systems don't do that--they either work, or they don't, and when they fail they stay that way until you find and correct the problem.

[pschauss]

Thanks for the suggestion. If my spare ignition module does not solve the problem, I will look at the fuel pressure issue. Is it really safe to use an automotive fuel pressure gauge on a boat?

[Bruce]

I don't recomend pertronix.

Any fuel pump pressure guage for reading low fuel pressure will have push on hose connection.

Make sure a clamp is used on those connections.

You can buy a 10 psi guage with threads and create a more solid connection on ebay cheap. Get a pipe t and install in line feeding carb.

If you have a steel line from fuel pump to carb, remove and replace with rubber for testing.

Look at the ends of the steel line and see if they are flare'd with a rotating nut to tighten. If so, you wI'll have to get barbs with inverted flare ends which will fit your carb and fuel pump fittings. Don't get regular tapered pipe threads, they won't work and will leak.

[Joseph Fikentscher]

coil. degrades as heated, after cooling ok again.

[pschauss]

I’m still leaning toward an ignition problem because I noticed a smell of gasoline fumes in the exhaust when it started to loose power.

The guy at my marina suggested that I look into a Thunderbolt system. It sounds like that might be a bit complicated because I don’t think any of the original wiring for it is left. Any thoughts on that?

[Tooeez]

The gauge I used had threaded connections, but whatever you use is for testing only--start the engine, see the pressure, shut it off.

[Tony Meola]

Peter

Thunderbolt ignition has been around a long time. It originally came with the big blocks in our boat when it was new. I think for you to convert to that system is more trouble and expense than you need to solve the problem.
Try a good race shop and see if they can help you out with a good system.

[coolair]

I installed MSD ready to run distributors on my engine rebuild and got rid of all the original prestolite/Chrysler ignition. They have worked find so far but the boat is not in the water so cant say as to how long they will last. Pretty easy to hook up.

[Carl]

I find it tought to fix problems I do not understand.

Like what your talking I become a parts changer. But if you have two motors you can become a parts changer detective.

From what I hear I think coil...don't replace but swap. Same engine has same problem you know it's not the coil. The other engine now has the problem...well you have an answer too. I used to go through coils and regulators till I found out my Ignition Relay was bad. It never shut off the ignition and slowly fried or wore the components out.

The lousy part of being a parts swapper is your never quite sure you have the problem fixed....and it's a lingering process.

[pschauss]

Carl,

I can’t swap ignition parts between engines because the ignition systems are not the same. Starboard engine has a Mallory distributor and takes a 12 volt coil. Port engine has a Prestolite and needs a 6 volt coil. Both distributors have electronic conversion kits. I carry spares for those and the coils.

[Carl]

Me...I'd make a choice of one or the other than make it my standard for both.
OR if something better is out...make a leap.
Especially for ignition where I'm as dumb as a brick...but I can change parts.
Problem travels I am onto something if I change and its the same issue, that is more than likely not the problem.
I find that to be one of the benefits of having twin screw...having an in house testbed.

[pschauss]

Anyone have experience with the Delco Voyager electronic ignition kit?

[Carl]

I chimed out as Bruce does not recommend Pertronic...but I am fairly sure that is what I had gone with when I bought my boat. I don't remember the name Pertronics...but the Ignitor logo stands out in my head.

As I replaced dual points I can say anything is better than that. I kinda learned that lesson with dads 440's before he went electronic. But his system had a module, resistors and wires. I can follow directions on ignition stuff...nothing more so was apprehensive. A mechanic friend told me what to order and it was too ez to install, he was right. I kept the old stuff in case I ever had a problem. 24 years I never had a problem, I just tossed the old points a week ago as they were buried deep under all my ignition parts, spare coil, regulator, wires, caps, rotors. Good thing to as if I had to put the points back in...I doubt I'd remember how to set them up again.

If Bruce can chime in with a better system then pertronix...that would be better then good. Sierra makes them too I think..

[Rawleigh]

Is there any play in the distributor shaft? Either up and down or side to side?

[pschauss]

Is there any play in the distributor shaft? Either up and down or side to side?

I did not notice any when I replaced the ignition module, but it looked pretty ugly inside.

http://www.ipernity.com/doc/307687/50146428

I put a couple of drops of oil on what appeared to be the moving parts before I installed the new ignition module.

[MarkS]

I have a similar issue with my starboard engine. Both have been converted to Petronix electronic ignitions some time ago. The starboard engine runs fine at start up and after motoring out of the harbor and up on plane for a distance once brought down to idle to troll it runs rough and misses eventually loading up and dying. It will restart without problem however it continues to run rough. I discovered that I only have 10 volts running to the coil on that engine and if I run something that takes a deep draw like a trim pump it drops off to almost no voltage at all. I also discovered that both coils on both engines have two sets of wires going to each side of the coil and that even with the key off the coils remain hot. In the process of testing we accidentally taped the wrong side of the coil with the tester and burned out the Petronix pick up which put an end to our missing voltage search last night. With all that said you may want to do a voltage test if you haven't already. My $.02

[pschauss]

Not sure if I mentioned this before, here is my configuration:

Starboard engine:
- Mallory distributor with the Pertronix module.
- 12 volts at the positive terminal of the coil
- Ballasted coil

Port engine:
- Prestolite distributor with the Pertronix module
- 6 volts at the positive terminal of the coil with the ignition on, engine not running)/ 10 volts with the engine running
- Unballasted coil
- If I take the distributor out of the circuit, I get 12 volts at the positive terminal of the coil with the ignition on and engine not running.

I spent about half of last summer figuring all of this out and I had both engines running well from the end of August until I went into the yard in November. Even if the problem that I am now having with my starboard engine turns out to be something other than ignition, I would eventually like to rationalize things so that I have the same ignition system on both engines, perferably something more robust than the Pertronix add-ons that I have now.