Old boat? Replacement or backup ignition system- Thunderbolt IV? Alternator?

[Fiat4Fun]

Howdy,
So, had an interesting last outing on Sunday. Went to our normal lake, and we were at the other end of the lake, and the boat died! No cell service, no boat traffic, and we were sitting dead in the water. Turned out fine, it was a short on a gauge that caused the main fuse to blow. Originally thought the motor went!
Took about a hour of sitting, even tried calling 911, but with no cell service, that didn't go well either. Got the boat running and headed back home. But it got me thinking about my old boat. I love the boat, been in the family forever, it's a 1986 Chris Craft Scorpion,21' with a 260 hp 5.7 with an alpha one, and has just under 800 hours on it. Been a pretty trouble free, but last year I did decide to replace the outdrive, since I had some small issues after hitting a rock and doing some damage.
Besides for a little water getting in, I have not had any real issues, and have it serviced every year, winterized, etc.
However, it's old ( like me) and started to think about things that might start to fail and leave us stranded. So, do any of you keep a spare fuel pump, alternator or ignition parts, controller and modules on board? Do these fail often? Or have you replaced them before they have gone bad? It seems like those are the three things that can leave you stranded if they fail. I would think a circulation water pump or power steering pump would not leave you stranded, Sounds like the Thunderbolt IV is not even fixable or even offered anymore? Even thinking of sticking a small electric trolling motor in the back, just in case we need to get to cell phone service!

Just trying to think ahead. Maybe I am just being paranoid, but would like to be as prepared as possible!
Let me know your thoughts
Thanks
Bob

 

[Eric 3.7LX Alpha 1]

I keep quite an assortment.....

All ignition parts, (run points so everything but new spark plug wires), fuel water separator, spare trim solenoid (even though could be jumped), spare length of wire, jumper wire with alligator clips attached to the ends, test light or multi meter, hose clamps, wire ties, (you'd be surprised what you can MacGyver with wire ties), electrical tape, carb cleaner, WD-40, spare alternator belt, 2-3' of 3/8" fuel hose with short sections of of flared 3/8" steel line. Can be used if the fuel line on the engine springs a leak. Had a couple of issues with auto parts store bought metal line. Some are selling a copper nickle line... better for rust resistance, but is terrible for vibration, breaks flare joints. Have switched back to regular steel line, but now keep the hose and ends in the box...


+ screw drivers, channel lock plyers, open ended wrenches and a socket set.

 

[Fiat4Fun]

Thanks for the response. I keep most of the things you listed, like the alligator clips with wire, that is something that I don;t have. After reading more posts about the Thunderbolt system, sounds like it is not something to worry about, but will keep my eyes out for a backup. Any other ideas are greatly appreciated.
Enjoy
Bob

 

[achris]

About the only thing to consider with the ignition system are the soldered terminals on the sensor inside the distributor. I've seen a few of them get corroded and stop working. Pull your dissy cap off and have a look at them. If they look a bit 'manky', either pull the sensor and clean it up and resolder the joints, or just buy a new one and stick it in. (Keep the old one as a spare?)

Chris.....

 

[Fiat4Fun]

Hate to bring up this old thread, but thinking about boating season coming up in a few months. I have added much more to my care package onboard, and was thinking of getting another Thunderbolt IV module as a spare. I see different ones offered on eBay, and I understand the V6 is different than the V8, so is there a different model for the 5.7 vs 5.0? Any advice on what to look for????

 

[NHGuy]

The V6 can be used on a V8, it just has a shorter timing curve. Some of the high performance guys use them so they can have a higher base timing value with less total advance.
I had an 88 boat with the Thunderbolt IV, it never even had a hiccup.
But one thing I did that I recommend you consider is to remove, clean and reinstall as many electrical connections as you can find. I did that my second spring with that 88 boat.
It was in 2010 I think. Everything worked super well after that. All the lights were bright, radio got clear, starter spun quicker, engine fired quicker power trim worked better. The trim had been wonky before. It was the same battery from prior year. I did plugs, wires, cap & rotor too though.
To clean the connections you disconnect the battery, unplug each component one at a time so you don't mix them up. Take a brass wire brush or emery cloth to them just enough to remove any corrosion, then reinstall. Definitely do the tach, coil and distributor, they can cause a no run condition.

 

[Fiat4Fun]

Thanks for your response. SO, the Thunderbolt module from a V8 would work on any of the older boats? Sounds like these might be reliable? Is worth having a spare? I don't see many posting that they are having issues with them, but something that old could fail, and if you have a spare it won't...... or it's covered. When you say clean all the connections, you are talking about all the stuff in the engine? That would make sense. Anything in the distributor that should be looked at or gone through?
Thanks
Bob

 

[72GT160]

The thunderbolts are reliable but, just as with any electrical part, when it fails your SOL. My Thunderbolt IV Ignition Module went out last year. Used parts seem pretty expensive and if the module went out, what's next? Just as Chris mentioned contact points in distributor. Your points should be inspected every year. I did some research on here and bought a Delco Voyager EST ignition system, no more point system. Very easy to install, had one question and customer service was excellent! Bought from Michigan Motorz.

Cleaning connections would mean, cleaning all electrical contact points, mainly battery and grounding points to the motor and go from there.

 

[Fiat4Fun]

So I thought the mercruiser thunderbolt system is a non-point system, with electronic ignition???
I will pop open my distributor cap when i get the boat out of the winter storage. Might grab a module just as a back up