OMC 350 not starting (I need suggestions on why)

HelloGuys

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Jul 20, 2023
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Hello,

I recently bought a 1991 21' Sunray boat with an V8 OMC 350. It was cheap because the sterndrive was accidented. When we went to check on the boat to buy it, the guy selling it started it up and it was running perfectly, starting in under a second, with no weird sounds or anything. We bought it, and when I was back home, the next morning, it started up fine. But then the next day (so two days after I bought it), it wouldn't start.

It wasn't the batteries, because they were on a charger, and we checked every fuse, relay, and connection and everything was getting power, so we thought it might have been some kind of protection or kill switch activated somewhere to stop the power to reach the starter. We can bypass it by using a screwdriver and make it spin, but then theres no spark happening, so it wont start this way either.

I called the guy that sold it to us, and he said that he never had a problem like this and its probably not a protection either since his mecanic would have told him there was one somewhere. (the whole engine was completely rebuilt)

But like I said, it is a boat without its sterndrive bolted on, so we think that it is something stopping the power since it isnt detecting the sterndrive behind. But them how did it start back at the seller's house and mine since it was never on all this time?

I spent two days trying to find something, like a loose cable somewhere or something like that, but never found anything.

I need help and sugestions so anything would do!
 

alldodge

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Welcome
I would like to know after agreeing to buy did you take it straight home or did you come back another day to pick it up?
 

alldodge

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straight home, so it couldnt have been a sabotage or anything
Good

Then lets work on voltages to were they should be. Probably something simple like a kill switch or other.

Put a meter on the Battery and see if you can read 12.7V
 

HelloGuys

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Good

Then lets work on voltages to were they should be. Probably something simple like a kill switch or other.

Put a meter on the Battery and see if you can read 12.7V
it was, and I forgot to say in the thread that everytime I turn my key, it makes a 'tic' sound like the power was cut or something
 

alldodge

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A Tic may just may just mean the Bat is dead.
First post mentioned it was on a charger, the charger is compensating for a bad Bat
 

HelloGuys

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A Tic may just may just mean the Bat is dead.
First post mentioned it was on a charger, the charger is compensating for a bad Bat
Might be, but I have two batteries, each relatively new (I don't need to change them till next year) and I can switch between both and it doesn't change
 

alldodge

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Might be, but I have two batteries, each relatively new (I don't need to change them till next year) and I can switch between both and it doesn't change
Good to know

Can you jump the start at the solenoid?
 

kenny nunez

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Jun 20, 2017
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3,290
It could be the boost solenoid. It will have a small yellow/red wire from the start side of the ignition switch with a #10 Y/R going to the main starter solenoid, #10 red wire should have 12 volts and possibly a small purple/black or black.
 
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