3.7 merc cruiser wont start

[terrylittle]

i bought this boat with a 3.7 merc 4 cyl had problems leaking so i changed all the bellows and the gimble bearing. took it out then a hose was cracked behind where u put antifreez so i repaced that. started driving and then after 5 min it just stalled. when i go to start it nothing just a little click or sounds like the starter is grinding i took it out seems to work fine. i can turn the motor with a ratchet but it just wont turn over good it seems like something is jammed. i also took the drive off and tried same thing im about to give up i really need some help.

 

[ahendri]

Re: 3.7 merc cruiser wont start

I am having some of the exact problems If anyone has any advice please share...

 

[Vadimk]

Re: 3.7 merc cruiser wont start

I'm by no means an expert but hers my 2?.
Just as a test, try removing the plugs and spinning it over by hand, it should be smooth.

 

[stonyloam]

Re: 3.7 merc cruiser wont start

Pull the outdrive and see if it makes a difference, looks like you might have to pull it anyway. good luck.

 

[mdlee]

Re: 3.7 merc cruiser wont start

Check the magnets on the harmonic balancer.... Mine broke off and jamed the crank shaft... first it was hard to turn over,,, then the starter started draging,,, then the clicking..

 

[terrylittle]

Re: 3.7 merc cruiser wont start

ok so the magnets on the harmonic balancer if it is that what do u think the repair would cost. would i need to do a bunch of work to fix it.

 

[terrylittle]

Re: 3.7 merc cruiser wont start

also does anyone know if ther is a motor that i could pretty much just drop in like without haveing to change everything possibly a 6 or 8 cylender.

 

[stonyloam]

Re: 3.7 merc cruiser wont start

ok so the magnets on the harmonic balancer if it is that what do u think the repair would cost. would i need to do a bunch of work to fix it.

$300 for an alternator kit and $0 to pull the harmonic balancer (DIY) and remove the magnets. If you have room to get a puller on it, no big deal.

 

[ahendri]

Re: 3.7 merc cruiser wont start

Sorry guys new to boats in general where is the outdrive located on the back of the motor?? and where is a good place to try and turn it by hand from there?

 

[Eric 3.7LX Alpha 1]

Re: 3.7 merc cruiser wont start

also does anyone know if ther is a motor that i could pretty much just drop in like without haveing to change everything possibly a 6 or 8 cylender.

Yeah, another 3.7. They are 1 of a kind.

 

[Eric 3.7LX Alpha 1]

Re: 3.7 merc cruiser wont start

Sorry guys new to boats in general where is the outdrive located on the back of the motor?? and where is a good place to try and turn it by hand from there?

Welcome to iboats ahendri, ya gotta start a new post for a new question. It gets confusing as hell with 2-different questions from 2 different people. Your question will get lost in this one and won't get the same amount of responses because people didn't see it in the title.

The drive is outside the transom attached to the bellhousing.

 

[mdlee]

Re: 3.7 merc cruiser wont start

$300 for an alternator kit and $0 to pull the harmonic balancer (DIY) and remove the magnets. If you have room to get a puller on it, no big deal.

Yesir that is the best way 2 go! If u fix the magnets u will later have problams with the lackluster water cooled volt regulater

 

[terrylittle]

Re: 3.7 merc cruiser wont start

i checked the magnets they all seem fine. i am really stumped.

 

[Eric 3.7LX Alpha 1]

Re: 3.7 merc cruiser wont start

Did you try removing all the spark plugs and rotating the engine? It should turn over relatively easy by hand or starter.

 

[ahendri]

Re: 3.7 merc cruiser wont start

Where are the magnets located??

 

[terrylittle]

Re: 3.7 merc cruiser wont start

i removed all the plugs and it turns alot eaiser, i can here all the pistons going up and down. man this is tricky stuff. i just cant seem to find the problem, anything eles might make these sounds and stop the motor from cranking. please help me guys.

 

[natemoore]

Re: 3.7 merc cruiser wont start

i removed all the plugs and it turns alot eaiser, i can here all the pistons going up and down. man this is tricky stuff. i just cant seem to find the problem, anything eles might make these sounds and stop the motor from cranking. please help me guys.

Are you saying that it won't turn over with the starter, even with the plugs out? But you can turn it over with a ratchet?

 

[terrylittle]

Re: 3.7 merc cruiser wont start

yes with the starter just barely turns and stops,after just a click but with a ratchet it turns. i thought it was the starter,but i took it out and it seems to work fine, also i was driveing the boat and it just died so can the starter function normally under no load but not work with a load. could , i also noticed my bolts for my motor mounts were loose. can i just tieten them up or how do u know were its suppose to be. i could move it 3/4 of an inch or so.

 

[Eric 3.7LX Alpha 1]

Re: 3.7 merc cruiser wont start

How long have you owned this boat. Has it run well in the past and just started doing this or is it new to you and doing this from the start?

 

[1993 Mariah]

Re: 3.7 merc cruiser wont start

i have a 3.0 and it has gave me trouble since i bought it currently i am having trouble getting it started also. how did u figure out how to turn it by hand?