GT40 ('96) ignition cutting out

My '96 Ski Nautique with GT40 has started to intermittantly cut out, as well as sometimes not starting. The engine has ALWAYS been reliable and starts within about 2-3 seconds every time. A few months ago it cut out briefly while under power (sometime stopping completely and then not starting, other times only cutting out briefly). When it would not start, it would take a number of tries cranking, and then suddenly, it would start like nothing had happened. It reminded me of when my deadman switch died (never use it, so when it went, I just jumpered it).

I'm 99% sure it is ignition; there's no sputtering, etc., it is either on or off.

I checked my jumper (no problem). The ignition switch was getting a little hard to turn, so I replaced that (thinking the ignition terminal might be getting worn). Tried it in the driveway after replacing, and no problem. Launched this morning, and it wouldn't start. Took about 6-7 crank attempts and then it fired up and ran perfectly for the next 90 minutes.

I want to trace the wiring. However, the manual that came with the boat when we ordered it in '96 has the old Pro Tech wiring diagram (different ignition) and then a EFI section (with the fuel cell). But there's no wiring diagram with the ignition that is in my GT40 in the manual.

Does anyone have one? I need to start tracing from the ignition switch back to the engine and all of the connections. And any other idea of what to check would be appreciated.

Thanks,

Gordon

Mark, sorry for the horribly late reply. Between 16-18hrs a day at work and having to put my boat in storage because my wife needs the garage space for her real estate business (she stages for the clients she lists and several closed at the same time), I haven't been able to get back to it until today.

It more or less did the same thing as two weeks ago; it probably took 8-10 cranks before it started (we just left it running while skiing). However, this time I put a volt meter at the dead-man switch and battery ground because I wanted to see if voltage was cutting out completely (no ignition voltage). It was about 11.5v with the ignition on. While cranking, it dropped to 7 or less, but once started, right up to 13v. As we pulled out, I shut it off, and started it again, and this time it dropped from 12 to about 9.5 but started right up.

When I got home, I pulled the high tension wire off the distributor and turned it over. Ignition was 12, and when turning over, 9+. Hooked the high tension wire back up and it started right up.

I can't see voltage dropping to 9 and below (6 when starting cold with no charge on the battery) being right, so that tells me a poor / corroding connection somewhere. Since the deadman switch is part of the ignition circuit, I may next check dash voltage to see if the whole dash is dropping the same amount, which would mean poor power/connection to the dash (I have a direct ground from the dash to the battery so I could do the same thing for the power side (since otherwise the wiring is from the battery to the back of the engine and then back up to the front.

However, while this potentially addresses the no start issue, it doesn't address the sudden cut out (although I haven't paid attention to the gages or had a meter hooked up when it has happened, so I don't know if it is the same issue/problem.

I do have a direct line off my battery that goes to relays for my heater, sub-woofer, and Stargazer, so I could run a line from the relays to the main ignition (power) switch and then see if my voltage in the ignition circuit drops as much or not.

Anyway, trial and error.

Thanks for the drawing!

An elderly couple walk into a fast food restaurant. They order one hamburger, one order of fries and one drink. The old man unwraps the plain hamburger and carefully cuts it in half. He places one half in front of his wife. He then carefully counts out the fries, dividing them into two piles and neatly placing one pile in front of his wife. He takes a sip of the drink, his wife takes a sip and then sets the cup down between them.