Bad Day on Water

PDACPA · **Posted:** Mon Jun 27, 2011 10:18 am

Took friends and Family out for scalloping on Saturday. Friend helps take the boat off trailer and the plug was not in as we had a heavy rain and left it off to drain on the hour ride. Bilge pump is going constant and I look in ski locker, full of water, jump in and put plug in. No problem, though not happy the starter probably got wet (was sort of brackish water as we were in a canal and not quite in gulf).

So we head out to the gulf. As soon as we hit the area to go snorkle, we bust the alternator belt (belt was fairly new, though just adjusted/tightened).

Everyone goes in the water and I pull out my spare belt and hook it up. Button everything back up and head to meet some friends in another boat who sent their gps coordinates. No problem, was a 8 minute run. Go scalloping and we decide to move to another spot. No sooner do we get to the new spot, the freshly installed (but older back up belt) alternator belt breaks. Only similar to the early break is it seemed to occur at idle speed not while running at 25-30mph.

Now we are out a few miles from the ramp, but with friends. Would be a long slow tow. However, I have my back up power steering belt. That belt is a tad shorter than the alternator belt. So I yank it all apart again as everyone scallops, and I am able to take the alternator off and lower it enough to get the belt on and re-assemble. I had to keep the alternator in its lowest possible position as opposed to up high, but guess what, it works.
We decide to head in as there were going to be storms later in the day. We run about 30 all the way to the channel. No issues. Almost thru the high speed part of the channel which ends with a slow no wake to ramp and the engine dies. Sputtering spitting then out. Check the belt. All ok. My buddy pulls up and ties up and starts towing us the rest of the way. I check the fuse and the ignition fuse is blown. I swap it out and try to start. It attempts to start and the fuse blows again. So I decide to leave it as we are just about at the ramp and work on it at home.

Half way down the no wake channel, my son says Dad there is smoke under the port gunnel. I look and see white smoke. At first I think the LED light maybe got turned on and wet, I open the engine compartment and there is a FIRE on the port side near the back (stern) of engine. Tell everyon to jump overboard, my buddy heads to a dock on the side of the no wake channel as I grab the fire extinguisher and put out the fire.

Get her on the trailer and take her home. The air cover is melted and some hoses. The underside of the engine cover insulation is melted and some black smoke marks on gel coat surrounding.

No idea what started the fire. Engine was off. The only thing we can think is something happened when I swapped the fuse and tried to start it and the fuse blew again. Maybe the starter getting wet at the start of the day?

Would appreciate any thoughts as to what caused the fire and where it was coming from! Cannot see the back of the engine so hard to tell if any burnt down in back. Worst thing, heading to the Keys in 4 weeks and the boat was supposed to go

I KEEP GETTING pixel height max 768 and will not let me post! This is something new since the picture size increase on the board! I resize the pics and it still gives me the error. Trying to post a pic.

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Walt · **Posted:** Mon Jun 27, 2011 10:47 am

People who know me wonder how I stay cool when things get rough. I just revert back to my days on the sub and say "If it ain't sinkin' and it ain't on fire, it ain't that big of a deal". You had both in the same outting! Hat's off to ya for keeping your cool. Hope the insurance gets you taken care of.

pet575 · **Posted:** Mon Jun 27, 2011 12:02 pm

Can't see how a wet starter would cause a fire to start. After busting two belts I'd be looking in the direction of the components that belt is hooked to. Maybe one of them has a seized bearing that caused the belts to break and heated up when you were on the third belt?

97_245_sd · **Posted:** Mon Jun 27, 2011 12:13 pm

I was thinking along the lines of an electrical overload or short that caused a very heavy load on the alternator. The heavy load caused the belts to break then blow the fuse and eventually heated up enough to catch on fire?

PDACPA · **Posted:** Wed Jun 29, 2011 1:10 pm

I think 97 is on target. I finally got a fresh look at the engine as I was out of town. There are two wires on the back side of the alternator (there is another one with a rubber boot too). The two wires appear melted and are close to a metal hose clamp and the wire clamp is discolored by fire and the most damage was just beyond that.

My guess is the starter had nothing to do with it.

The two wires on the alternator touched the metal hose clamp which caused the alternator to short out? fail? (not sure of how to describe it). This caused the fuse to pop (please correct me if I am wrong as I am by no means a mechanic). At the same time, this wire to metal contact caused the plastic wire covers to melt or a spark was caused and somehow the plastic started the fire.

Any thoughts appreciated on my logic.
Thanks

ric · **Posted:** Wed Jun 29, 2011 11:41 pm

Sounds like that electrical short you described from that clamp thing. 70+ amps is more then enough to start a fire. or weld a cracked trailer beam.

PDACPA · **Posted:** Thu Jun 30, 2011 8:12 am

Thanks guys.

I think the initial engine cut off was the popping of the ignition fuse which was caused by the alternator wire sheathing being worn or melted off and touching the hose clamp.

Then as I was being towed, I swapped the fuse and the engine tried to start for maybe 5 -10 seconds then the fuse popped again. At this point I think something heated up or created a spark and the plastic cover started on fire.

pet575 · **Posted:** Thu Jun 30, 2011 11:26 am

So, did the heat generated bust the two belts then? Heat transferred into the pulley and just melted them as they spun?

Jafo4U · **Joined:** Wed Jun 22, 2011 2:33 am **Posts:** 1026

Holy Jesus I felt like I was on the boat with you while it was happening you had me so involved in your emergency! Chief of the watch sound a firealarm. On the one MC dive dive dive make your depth 150 feet smartly. Lol!! That's the first thing that came to mind.

Jafo4U · **Joined:** Wed Jun 22, 2011 2:33 am **Posts:** 1026

Thank god all of you and your family are ok and kudos for your son noticing the fire!

wkearney99 · **Posted:** Fri Jul 01, 2011 9:23 am

First, glad to hear it didn't get worse.

It's often considered a really bad idea to open an engine hatch when there's known to be a fire in there. The in-rush of fresh air can cause the fire to intensively increase. Some boats have a port into which you can spray a fire extinguisher. Other boats have a built-in extinguisher system that triggers automatically. I'd wonder if one of those would have gone off when your fire started. Hard to know. But it sounds like you caught the problem quickly.

It also sounds like you're on the right track regarding the fire starting from the insulation. It's odd a fuse or breaker didn't trip to stop it. But sometimes when there's a failure outside the range of expected problems things can happen.

It's important to inspect all wiring inside a boat. Over time things shift, due to gravity, boat motion, vibrations or other activity (moving the alternator perhaps). Boats have an un-ending amount of things to maintain.

Jafo4U · **Joined:** Wed Jun 22, 2011 2:33 am **Posts:** 1026

Definitely will inspect everything on my boat once she is here sometime next week.

LouC · **Posted:** Sat Jul 02, 2011 7:41 am

It sounds like the cause was a dead short to ground, the alt wire probably gets 12 volts straight from the harness from the starter solenoid, and since that's battery voltage, large wire size, 600+ amps, that would get REALLY hot fast. Its a good idea every so often to look over all the wiring harnesses with a bright flashlight, to make sure nothing is worn through near any metal component bolted to the engine, because that will cause a dead short to ground.

Lucky your son noticed it. Maybe a smoke and fire detector in the engine compartment of inboards is a real good idea, in addition to gas vapor detector....

PDACPA · **Posted:** Tue Jul 05, 2011 4:29 pm

Thanks guys.

The alternator belt did not melt. It looked sort of shredded like if you were tearing beef jerky. (wish I had grabbed a picture but with some many people around it was misplaced (I bet in the trash bag)).

Why the belt kept breaking is beyond me. It was not touching the other belt and appeared to move smoothly. I will say the wheel on the alternator is pretty corroded with some rust. I cleaned it while on the water, but had no steel brush. I am anticipating that being replaced.

Is it possible that the belt was not aligned perfectly and caused it to break? I will say this, the power steering belt is much thicker (just a bit shorter) than the alternator belt. Would i be possible to replace the alternator belt with the correct size, but thicker?

Lou - you confirmed what I was thinking. The starter link to the alternator. I am sure that when I put in the new fuse and tried to start the engine, some spark or heat was created by the alternator wires touching the hose clamp.

I also think the plastic cover of the wires wore off by rubbing as we were running back to the ramp. It was not rough, but normal running would cause some bouncing of the boat and maybe shake the engine or maybe there is heat there.

My friend was telling me about that port that you stick a fire extinguisher in and I need to look into that. My boat is small and I am sure that is why it does not have that. A smoke detector in there might be a good idea too.

Had I not opened the engine lid, I have a feeling the boat would have burned up. I know it provided oxygen and gave the fire more life, but I was right there with the extinguisher and was able to put it out quickly.

JordanFTW · **Posted:** Wed Jul 06, 2011 11:18 am

If a fuse blows, never just replace it and try again... You should have pulled the engine cover and looked for electrical issues, starting around the alternator since you were having problems with it anyway. Could have saved you allot of trouble it would seem.

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Bad Day on Water

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