mercruiser 470 sudden stall and no restart

[olazabel]

I was on the lake tonight, cruising around with the family and the boat very suddenly stalled. No hesitations or sputters, just quit pretty instantly. Had to get a tow back to the dock. It turns over, cranks, but won't fire. Tried some starting fluid still wouldn't fire. The engine has always run fine,and seemed good right up until it cut out.

From what I've read here so far, I'm thinking its either a fuel delivery or electrical issue.... maybe more likely electrical because of the way it quit.

I'm not really sure where to start as far as diagnosing the problem. Fuses? wires? Ignition switch? coil? maybe fuel pump?

Any help would be greatly appreciated. The kids and wife want to be on the lake this weekend.

(I installed an alternator kit on the 470 a couple summers ago if that makes any difference)

 

[Eric 3.7LX Alpha 1]

In the "Adults Only Sticky" at the beginning of this forum... there's a ton of info... where these came from..

How points ignition system works.

http://forums.iboats.com/forum/engin...-system-works?
t=329742&p=2186518

How To: Troubleshoot a Points Ignition System

http://forums.iboats.com/forum/engin...ystem?t=335407

HOW TO: Testing your boats fuel system.
http://forums.iboats.com/forum/engin...ystem?t=283269




It could be the coil or points, but will be best to test first, instead of just buying parts and hoping that's what it is.

Your going to need some tools/ test instruments....

test light or digital multi meter.... or both even is nice

an inline spark tester like this one from Lisle #20610 for 12 bucks:
http://www.amazon.com/Lisle-20610-Inline-Spark-Tester/dp/B0002STSC6

 

[Bondo]

I'm not really sure where to start as far as diagnosing the problem. Fuses? wires? Ignition switch? coil?

Ayuh,.... Is there power at the coil's (+) terminal,..??

 

[olazabel]

Thanks for the quick response, I had to go to work for a few hours so I can pay for more boat parts.

Yes, with the key on there is power at the (+) terminal on the coil. I just used a test light, didn't put a multimeter on it yet.

 

[Bondo]

Ayuh,..... Next step is the points, which fires off the coil,....

 

[olazabel]

OK, so I take off the cap, and what do I look for?

 

[olazabel]

Or should I just replace them?

 

[Bondo]

OK, so I take off the cap, and what do I look for?

Ayuh,.... Follow the links Eric posted,....

 

[olazabel]

ok, will do. thanks.

 

[wahlejim]

Does your engine have a circuit breaker? Have you checked that yet?

 

[salty3rd]

Does your engine have a circuit breaker? Have you checked that yet?

if he has power at the coil and it is turning over his circuit breaker should be fine. I am always suspicious of a bad coil, but I would make sure the coil to distributor wire is tight, and your distributor is working correctly. I would pull a plug and hold the hex part against a good ground to see if the plug is firing. A better way would be to buy the tool that Eric suggested. If it isn't firing make sure the distributor is actually turning when you turn the engine over. I had a bad gear on my 470 distributor last year. If you have no spark and the distributor is turning, get yourself a coil.

 

[olazabel]

circuit breaker was good

I took the cap off and saw some corrosion around the points and condenser. I ran some sand paper through the points a few times and the boat fired up, but started harder than normal, and then seemed to run fine on muffs.

now i'm wondering if that possibly could have been the problem or if it was just a loose wire or bad connection like you mentioned .

is it possible that corrosion on the points could cause the boat to stall and not restart after it had been running fine all summer and for the 15 to 20 minutes before it stalled?

don't want to get stranded on the lake again

I've been thinking about switching over to a pertronix ignition and coil for a while. are they worth the extra $ to not have to deal with points anymore?

 

[johnkom]

No Title

Changed to a Crane Cam system on my '76 Ford 351, Mercruiser 233 a couple of years ago. And absolutely love it. Very good starting now. However, I do carry the points and condenser in the glove box if I should ever need them in an emergency.

JK