1969 125hp Merc v6 won't turn over

[Lalli]

Hello out there,

This question may be impossible, but sometimes a challenge is good. We just bought an old larson boat with a 1969 1250 Merc v6 on it. The motor won't turn over. The gas is hooked up and the engine is getting fuel. When you turn the key, it sounds like it's going to start but never turns over. I'm sure it could be a million things, but do you have suggestions for where to start? We are relatively new to boating. Our last boat was a 16' fiberglass two seater with a 57 Johnson. And it ran good. Thanks in advance!

Okay, I added new information that will be helpful in solving this mystery. It is written below.

 

[ThumbPkr]

Re: 1969 125hp Merc v6 won't turn over

I don't think Mercury made a V6 in 1969.No matter.....the problem would probably be the same whether it was a V6 or whatever.It sounds like a solenoid going bad.I have a '69 650 with the same problem which will have to be attended to before the motor goes back in service.Ron G

 

[BF]

Re: 1969 125hp Merc v6 won't turn over

Hello out there,
it sounds like it's going to start but never turns over.

Hi & welcome... you'll get better help if you are more precise in what's happening. How does it sound like it's going to start? Do you mean that when you turn the key, the engine is cranking?? When you say it never turns over, do you mean that it doesn't ever fire, (just cranks?) Or do you really mean that when you turn the key the engine doesn't turn over at all (does not crank)?? If so, what do you mean that it sounds like it's going to start?

If no, crank at all, then yes could be bad solenoid, poor electrical connection, bad ignition switch, bad starter, dead battery. If it cranks but doesn't fire, then it's probably fuel problem or could be lack of spark.

and yes, if your engine is that old, its' an I6 not a V6

good luck

 

[Lalli]

Re: 1969 125hp Merc v6 won't turn over

Okay, I talked to my husband and got better information. He says that the engine turns over, but never starts. When you turn the key, the engine cranks but doesn't start. The engine is an inline 6, my bad. Every once in a while, when trying to start it, the engine has a little backfire, sounds like a chug. If that makes sense.
The guy that had the boat before us, said that the engine was running great. He noticed that the fuel lines were a little leaky so he replaced them. He also said that he replaced some wires that were looking old. Unfortunately, we don't know which wires he replaced. After doing both of those repairs, the engine is in the state it is now. Joe will check around tomorrow to try and find out which wires were changed. Hope this helps!

 

[JB]

Re: 1969 125hp Merc v6 won't turn over

Hi, Lalli.

Go to the Engine FAQs, "Outboard won't start" and verify that you don't have a fuel problem or a compression problem. Let us know what you find.

Remaining possibilities are ignition or timing. A "chug" sounds like either timing or fuel, but if the "backfire " is a loud bang it is sure to be timing.

 

[cannonford57]

Re: 1969 125hp Merc v6 won't turn over

a little backfire means 2 things../it has fire and fuel....both are good things/.the internal harness in probably going to be the "bad" wires he finds and i believe it is avaivaible aftermarket...all is not lost..