Still fighting the 'no start when hot' issue....

[Mattyman]

I took the boat (86 TS6M) out today for the first time since last year to properly try to diagnose the issue that I encountered last year. The boat starts without issue when it is cold. If I cruise around for about 20 minutes and shut it down, it will not want to restart until it cools down again. I confirmed that it is not vapor lock. I had my tools this time and I suspected an electrical problem, so when it occurred again today, I checked for spark. Nothing. I put my hand on the ignition coil and it was very hot to the touch, as in get burned if you hold your hand there longer than a second or so. I had a new coil with me so I installed it and the boat started up. However, after some time the same thing happened. Boat would not start and coil was extremely hot and no spark. I got some lake water and splashed it onto the coil and let it sit for awhile and then it started. It idled for awhile and then died and again would not start.

The old coil, which I got awhile ago from Advance Auto did not require an external resistor. The new coil was a different brand just to try something different. It appears as though the coil issue is a symptom of some other problem causing the high heat. When I got the boat, it did not have points. I had an issue at one point where the original electronic pickup in the distributor failed and replaced it with a new Mallory E-Spark conversion kit. Any ideas on what may be going on or where to continue checking? Thanks for the help.

[ruby23m]

It sounds like you have the same problem i did. I found that my float was not set properly and was causing a lot of fuel pouring into the engine. I bent the float tab to adjust,, took it out monday and had no problems as i did before. Before the fix, fuel was being dumped into the engine 15 to 20sec after i would shut her down.

[Mattyman]

I confirmed it's not fuel/carb related. When it is hot and won't start, I don't get any spark to ignite the fuel.

[Salty87]

have you cleaned and tightened battery cables in last few years?...don't forget the ground on the block. i don't see how they would make the coil hot but they can decrease the amount of power the starter gets. a hot block is harder to turn over. cables need to be replaced by now if they're original, most likely. do they crackle and sound brittle when you bend them?

[michael hunter]

Does the Mallory kit require a ballast resistor? I would not buy electronic parts from Advanced or Auto Zone . Contact Mallory and see if you need a resistor coil or not then go to Skidim .

[Mattyman]

I was able to find the box from my Mallory conversion kit and it indeed shows a ballast resistor. I don't think my boat has one but I'm not sure if there is a resistance loom wire or not. I ordered the Mallory resistor as it should have one but am still doubtful if that will resolve my problem. I'm also going to redo all the wiring. I put in new battery cables and a starter last year. Hopefully that resistor fixes my burning hot coil and loss of spark issue.

[Mattyman]

Well, I'm still frustrated. I installed the new ballast resistor and am still having the same issue. I found the original resistor, which was shot and could see where it was bypassed. Before installing the resistor, I checked over the wiring and checked voltage on my ignition wire. There is an area where I think 3 wires come together to get ignition power (ignition wire, alt. wire, and another which I can't remember right now). When I checked the battery voltage, it was around 12.6 volts. When I checked voltage at the point where the ignition wire was tied into the others, it was around 10.5 volts. I'm not sure where the 2 volt drop is coming from at this time. When I installed the ballast resistor, voltage to the coil was around 7 volts. The boat started and ran fine with the resistor installed but after about 20 minutes, the coil was hot and upon shutting down the boat, it would not restart because spark was lost. I poured lake water on the coil and after about a minute it started up again.

When it was running, I checked to see what the battery voltage was at and it was around 13.5 volts, which tells me the alternator is charging properly. For the heck of it, I measured voltage between the positive side of the coil and ground and got around 7 volts, which was expected and then I measured voltage on the negative side of the coil to ground and read about 1 volt. I'm not sure what that tells me at this time but I think I have some more wire tracing/testing in store for myself.

If anyone has any ideas or things to further test on the ignition circuitry, please let me know because I'll do just about anything to get my boat running properly. Thanks.

[CornRickey]

Check your ground straps especially on your distributor. Google "hot coil" you'll get a bunch of hotrod guys. There's a bunch of stuff in there on it. Good luck.