Mercruiser 3.7 Starting/Starter Question

[salty3rd]

Re: Mercruiser 3.7 Starting/Starter Question

My 3.7's have studs; I know this because every time I change one of the starters one of the studs comes out with the nut. Yours could be different, but I would try and back them out to see if they loosen up. I know it is tough because you can only get one flat at a time with the wrench; but thats a 3.7 for ya..Good Luck

 

[dccordell]

Re: Mercruiser 3.7 Starting/Starter Question

Rinker... can you not put your finger into the small space between the flywheel and the rear part of the starter to feel if there are bolt heads in there? I just went out and checked mine (470, motor in the boat) and I can put my fingers into the opening in the flywheel cover where you can see the rear of the starter, and I can slide my fingers under the edge to feel those "humps" that you are talking about. Mine don't have bolts, just bolts threaded into the block from the starter side (but mine is the older style).

I'm thinking it should either be the studs threaded into the block with nuts on starter side (with no head on the back side), in which if the hole thing is spinning with the nut on the starter side, it should eventually back out.... OR it is a bolt inserted from the flywheel side and then a nut on the starter side. You should be able to feel back there to see if there is a bolt head back there or not. That will pretty much tell you what you have...

Keep in mind, since it is such a tight spot with the wrench, as you are turning that nut and it seems as though it isn't backing out, are you SURE that it isn't backing out?? Since it is such a slow process, it can appear to not be coming out at all until a few turns. Just something to keep in mind...

 

[stonyloam]

Re: Mercruiser 3.7 Starting/Starter Question

As near as I can tell, if you have a 83 or newer motor this is what you should have: (nut and bolt) http://www.mercruiserparts.com/Show...nbr=10&bdesc=STARTER+MOTOR+AND+WIRING+HARNESS If you have a 82 or older, this is it: http://www.mercruiserparts.com/Show...bnbr=1&bdesc=STARTER+MOTOR+AND+WIRING+HARNESS bolt only, but it is certainly possible that on some of the engines the bolt has been replaced by a stud and nut, either by po or dealer. I am going to go take a look at mine tomorrow LOL.

 

[86Rinker19ft]

Re: Mercruiser 3.7 Starting/Starter Question

well its DEF. not the style with a bolt that holds the starter on. I tried backing it out for at least 20 turns and it seemingly went no where. I guess I will try a little longer (this is a TRULY MONOTONOUS task as you all have pointed out because of clearance and the 1/16th turn you get each time) but I will keep trying and most likely have to pull the engine again (not to bad a task, maybe 50mins-ish). Thanks though for all the thoughts/suggestions here! TRULY APPRECIATED.

 

[stonyloam]

Re: Mercruiser 3.7 Starting/Starter Question

Are you sure you are looking in the right place for a bolt head? If you turned it 20 (the nut) times, you must have a bolt, a stud would have unscrewed. Here is a drawing of the flywheel housing. The starter "hump" is in the upper right, and the bolts go through those two holes, and the heads should be exposed behind the housing, gottta be there, and you shouod be able to get a socket on them. http://www.mercruiserparts.com/Show....png&inbr=908&bnbr=190&bdesc=FLYWHEEL+HOUSING should be able to feel several other bolt heads back there, those have to be there LOL.

 

[Don S]

Re: Mercruiser 3.7 Starting/Starter Question

Here is a picture from the parts diagram for your SN.
The bolt is 4 1/2" Long, so just put you hand back behind there and find it.
No one said that everything on boats is easy to get to. as a matter of fact, just the opposite is true in most cases.

 

[86Rinker19ft]

Re: Mercruiser 3.7 Starting/Starter Question

Well, that clears it up! I feel like QUITE the DUMB-*****. Yep, I have 15 years of automotive mechanical experience and yet something as simple as a bolt head on the back of the bell housing throws me for a loop. I went out this morning and put a wrench on the nut side, then put my hand behind the bell housing and felt for any movement........sure enough there is a bolt head behind there! I will say its a bit of a contortionist act to get one hand with wrench on one side and the socket on the other, but I'll manage Thanks again everyone!