mercruiser 3.0 inboard

[dazid1]

Can anyone help
I have only ever played with outboards before and I am making what I first thought was a simple job into a marathon.
I have a 1972 winner wildcat with a 3.0 litre inboard, the engine needed a rebuild and the parts were quoted as 600 plus. So I picked up an 1984 mercruised 3.0 with 840 hours on it, I had to change the bellhousing from the origonal and tried to fit it.
Looking through the gimble housing from the back of the boat with the engine in place the engine is about half an inch too low and maybe a quarter to the offside, I have packed it with steel washers (4) and it is about right height wise but still too far to starboard, how can this be as the casting sets the side to side up or have I missed something. Also the workshop manual says the lining up of the drive shaft is very important and mentions a fibre washer inbetween the engine and transum plates, with a spring washer inside it??? how important is this, any help would be apreaciated.

Thanks
Darren

 

[WillyBWright]

Re: mercruiser 3.0 inboard

Welcome to iboats.

There will be a heavy spring on each side of the transom bracket where the bell housing rests. There is a thick fiber washer that goes around them. The rear bolts go through these assemblies. Without them appropriately placed, alignment can't be done. If you're using big washers in place of these, the rubber mounts won't cushion the motor. There's also spacers above and a nut that slides into a recess on the transom bracket.

If that's an original motor, it's probably a 2.5L. Same thing as a 3L with a smaller bore. Carb jetting may need to be addressed if you're putting a 2.5's carb on the 3.

 

[Haut Medoc]

Re: mercruiser 3.0 inboard

Welcome to iboats....
The answer is: yes!
You need to put the proper spacers there or you will have trouble......
There are kits available for that.......
Failing to get the alignment right will cost you a new engine coupler & you will need to pull the engine again to replace it & the washers.....
Take the time to get the correct parts & do it right.....
It will pay off in the long run.......
PS, you will need to come up with an alignment tool some how as well......
You cannot eyeball it.......

 

[dazid1]

Re: mercruiser 3.0 inboard

Thanks guys, the book doesn't mention any spacers, Iwill have to source them over here somehow,
Do you know if the bolts are specials as well? I have put 100mm long 12 mm bolts in at the moment going in from the top but there isn't room for a nut underneath as the bolts go right next to the casting on the transum.??:

 

[Don S]

Re: mercruiser 3.0 inboard

ALL of the bolts, nuts, washers, spacers, mounts, and everything else is special. And if it isn't right, you will be burning packs of $100 bills.in damaged parts.
You need the proper OEM manual for your particular engine and outdrive. The aftermarkets usually only hint at what actually needs to be done or how to do it.
Here is what the rear motor mounts should look like.

 

[dazid1]

Re: mercruiser 3.0 inboard

Thats pretty much what i have got, inside the "C" casting is a metalastic bush, one each side. Not sure what the spacer on top of the unit is "G" is that refering to what I am calling the bush that presses into the rear engine mounting casting? Is it the spring washer that gives the engine the height or is it the fibre washer, if its the fibre washer I will need 5 or six of them to get the height.

D

 

[WillyBWright]

Re: mercruiser 3.0 inboard

The fiber washer is only there to keep the bell housing from chattering against the transom bracket. The spring crushes flat and becomes a spacer. The spacer above keeps the big flatwasher on top from locking the bellhousing rigid against the rubber motor mount. The alignment is adjusted by raising or lowering the fromt motor mount. There is no side-to-side adjustment on an inline motor.

 

[Bondo]

Re: mercruiser 3.0 inboard

I will need 5 or six of them to get the height.
inside the "C" casting is a metalastic bush,

If you're That Far Out,......

The "metalastic bush" sometimes Fails,+ slips down.......

I believe I've seen Don post about a Kit to renew them to the proper Height..........

 

[dazid1]

Re: mercruiser 3.0 inboard

Yes I do seem to be that far out, the metalastic bushes are ok, I have changed one of them and it had a thin aly spacer that went in first, I wonder if I could put two of them in to raise it? I cant think without looking if it fits that way round, ie goes in from the bottom, it thats the case a thicker washer will make more height wont it? Any idea where I can get the bits I need.

D