1985 Mercruiser 140 hp 3.0 locked up

[mlkweedp]

Help!, My boat wont start, we adjusted the points, replaced plugs and plug wires, brand new battery, sprayed engine start in and put gas in but it wont start. Sometimes it just clicks. Any suggestions? Sometimes it trys to start but doesnt. I just picked it up from the marine mechanic and he said it might be locked up somewhere because they can barely turn the flywheel.

 

[Fishermark]

Re: 1985 Mercruiser 140 hp 3.0 locked up

Did this "marine mechanic" do anything else? Like removing the spark plugs to see if there was water in the cylinder? Or removing the drive to see if it is locked up instead of the engine?

By the way - just for future reference, it is better to respond to your original post since it is the same issue.

 

[mlkweedp]

Re: 1985 Mercruiser 140 hp 3.0 locked up

he did remove the drive and it was fine, and remover the sparkplugs, I heard from my brother someone put diesel in their sparkplug holes and over filled the oil to get the engine loose. is that reasonable

 

[Fishermark]

Re: 1985 Mercruiser 140 hp 3.0 locked up

I would suggest transmission fluid or even Marvel Mystery Oil instead of diesel. I don't believe overfilling with oil is necessary.

 

[mlkweedp]

Re: 1985 Mercruiser 140 hp 3.0 locked up

So do I put this oil in there then try to start it or what?

 

[Fishermark]

Re: 1985 Mercruiser 140 hp 3.0 locked up

After removing the sparkplugs, pour it into the cylinders and try turning the engine by hand. Will probably need to rock it back and forth first. You can usually put a pry bar between the bolt heads on the water pump pulley to use as leverage to turn the engine.

 

[mlkweedp]

Re: 1985 Mercruiser 140 hp 3.0 locked up

Does it have to be trans oil or can it be any oil?

 

[Fishermark]

Re: 1985 Mercruiser 140 hp 3.0 locked up

Transmission fluid has more of a penetrant quality to it than regular motor oil.

 

[mlkweedp]

Re: 1985 Mercruiser 140 hp 3.0 locked up

ok, i used Marvel Mystery Oil and its sitting right now, i'll try to turn the flywheel in a few minutes, then what?

 

[Fishermark]

Re: 1985 Mercruiser 140 hp 3.0 locked up

Once you get it to turn freely (and it might take a day or two as opposed to a few minutes) - then you can put the plugs back in and try to start it. I would change the oil before hand - and make sure you supply water to the engine.

 

[mlkweedp]

Re: 1985 Mercruiser 140 hp 3.0 locked up

I might have to wait till tomorrow because as of now it is only turning the water belt pulley and forceing the belt to turn as well but the fly wheel is not turning yet.