Problem with Gimbal Housing Fit

[seven_magnum]

My restore thread is here
http://forums.iboats.com/forum/boat...t-islander-221-rebuild/page13?_=1440814246091

I'm up against a wall- I am trying to get the gimbal assembly in the boat but its not happening- the steering arm at the top interferes with the top of the key hole? I can't get it in for the life of me. I am trying to use the "new" gimbal assembly and wondering if there is a difference? The boat had a '76 Mercruiser 165 with MC-1, I am installing another Mercruiser 165 with MC-1, at least I thought? I took the gasket, and it matches the gimbal ok, but needed trimmed- the local boat shop I bought it from just said make it fit at the bottom, that's why she's cut down there. Anyhow, the bottom holes match up fine, but then the top two studs are in the wrong place? I would like to use this housing because it's in much better shape than the old one, but to do that I need to drill new holes in the transom at a minimum. Any help would be great!

 

[jbcurt00]

Looks like G64 had to re-drill his upper mounting holes:

I cut out a new keyhole shape and drilled a couple of new holes for my new-to-me MR-1 drive. FYI, the bottom 4 holes lined up, the top two needed to be raised. '64 IA drive to an '84 MR-1.

Any chance you have the opposite problem? Needing to drill the holes lower?

 

[jbcurt00]

BTTT

 

[achris]

The MC1 had 2 (sightly) different cutouts. The earlier one with the trim limit switch above the top of the bell housing can be altered to make a later housing (trim senders on the gimbal ring) by filling the upper pair of the 4 'middle' bolts and drilling slightly (about an inch) higher. The centre of the cutout then needs to be widened slightly...

If you are trying to go the other way (fitting an earlier housing into a later hole), not so easy....

Chris.........
(EDIT: Looking at the photos again. You are trying to put an earlier housing into a later hole).....

 

[Watermann]

The older MC has the top holes 1 inch lower than MR and A1. Most of us upgrading from the old MCs have had to drill out new upper holes. Looks like you're trying to go the other way with this assembly. I wouldn't try getting the older transom assembly to work, go with the newer that your transom is already set up for. I'm thinking the outer gasket on those should be a foam seal rather than cork?

Going to check out your Islander thread.

 

[seven_magnum]

Thanks for the replys! I just moved this weekend, and this is the first I had internet access. (Installed a few minutes ago.)

So It appears I have an older MC-1? I never would have thought. I must have been right at the change in model years. The boat this came from was a 75 Crestliner, going into a 76 Starcraft.

The Main problem with the original was the steering arm inside the transom.The last I can recall it moved 3/8" back and forth without moving the drive, and I think I recall reading that this was way out of spec and hard to service. Can I rebuild it with a new steering arm? Or should I look for an Alpha 1 and bolt the I6 up to that?

Many thanks!

 

[achris]

Can't rebuild. No parts available. I would look for an Alpha 1, but be aware, it will come with the later model (than the later MC-1 :facepalm inner transom plate, which there is no flywheel housing for the in-line 6 to match, and the longer drive yoke, which also doesn't fit the in-line..... But you may be in luck.

I have measured but not physically tried, the newer inner transom plate for a late model MC-1, and it should fit. That means it should also go the other way. You *should* be able to find an R, MR or Alpha One Gimbal housing and put the later MC-1 inner plate on it. Then your 165 will drop onto it. Then check the insertion depth of the new drive yoke. If it's too deep (check against the old yoke insertion depth), just pull the shorter yoke off your existing MC-1 drive and fit it to the newer drive.

But wait, there's more.... As the flywheel housing on the 165 was the same as the one for the 120 and 140 (of the same era), and they DID continue (the in-line 4s) past the 165 and put them with Alpha Ones, then a flywheel housing off a later 120 or 140 *should* fit your 165.... But you would need to check to see if you would need to change the coupler...

Chris.......

 

[seven_magnum]

Thanks achris. Just to be sure, the steering parts from the old MC1 won?t fit the newer one?

It seems like an alpha 1 setup is the way to go. If I bought a doner with the 120/140, I could use everything except the outdrive. I remember on here somewhere that the MC1 outdrive was narrower where it fits the gimbal than the Alpha 1? An SEI would probably be the ticket to get this to work like it should.

I am kicking myself, I should have just got a 4.3 when I was donor shopping in the first place:facepalm:

 

[Watermann]

Sell off the 165 stuff and start looking for a nice 4.3 donor! You won't be sorry, they're a great motor.

 

[achris]

Thanks achris. Just to be sure, the steering parts from the old MC1 won’t fit the newer one?

Correct.

It seems like an alpha 1 setup is the way to go. If I bought a doner with the 120/140, I could use everything except the outdrive.

Only because the ratios are different. The drive would physically fit. And even then, all you'd need to swap is the top box...

I remember on here somewhere that the MC1 outdrive was narrower where it fits the gimbal than the Alpha 1?

Incorrect. Bolt up replacement.

An SEI would probably be the ticket to get this to work like it should.

I am kicking myself, I should have just got a 4.3 when I was donor shopping in the first place:facepalm:

Good choice. That's what I did.... Never looked back.

 

[seven_magnum]

Ok, I am officially looking now, we will see what I find.

How wide is the 4.3? The aluminum stringers in my hull next the the engine are much higher than most of the islanders I have seen, I am concerned I am going to have to cut these and rig up some new ones. I know this isn't the end of the world, just trying to prepare for it.

Also, I see some deals on other MC-1 boats with 140's, this would seem like a fast easy swap with no holes to drill or anything. Is it worth the extra work to get away from the MC-1 gimbal assembly?

I would like to keep my 165 just because I have so many parts and it's wearing a new manifold and riser. (I have 3 engines sitting in the shop, 1 complete and the others just need manifolds, carb ect.) but the idea of those extra ponies is hard to pass up.

 

[Bondo]

Ayuh,.... Another MC-1, 140 is a drop in horsepower, 'n a different gear ratio,....
Definitely the quickest way back onto the water though,....
A later gimbel housin' oughta swap in for yer current motor, 'n drive,...

Goin' to the 4.3l is a substantial jump in horsepower,......

I don't remember the motor mount widths, but the overall motor is 'bout 32" or maybe it's 34",...
Same as All the V-motor Chevys,...

The motor mounts for mine were a piece of cake,...
Bent 'em outa .090 aluminum sheet,(aka:street sign sheet aluminum) 'n pop-riveted 'em to the stringers, 'n ribs,....
Don't go crazy thinkin' bigger is better, hada cut mine down so's I could change the starter,...
Hada trim the port-side to make changin' the oil filter easier,...
'n of course, ya gotta be able to reach the drain plugs,......

 

[Watermann]

Ok, I am officially looking now, we will see what I find.

How wide is the 4.3? The aluminum stringers in my hull next the the engine are much higher than most of the islanders I have seen, I am concerned I am going to have to cut these and rig up some new ones. I know this isn't the end of the world, just trying to prepare for it.

Also, I see some deals on other MC-1 boats with 140's, this would seem like a fast easy swap with no holes to drill or anything. Is it worth the extra work to get away from the MC-1 gimbal assembly?

I would like to keep my 165 just because I have so many parts and it's wearing a new manifold and riser. (I have 3 engines sitting in the shop, 1 complete and the others just need manifolds, carb ect.) but the idea of those extra ponies is hard to pass up.

You can take a look at my full restore Chief thread and get an idea of what your looking at doing. I also have a PDF spec sheet for the 4.3 that shows every single measurement you could possibly imagine. If you want the file PM me with an email addy.

 

[achris]

...How wide is the 4.3? .....

770mm

 

[seven_magnum]

Alright, I have a date to go look at a 4.3 and wondering if there is anything I should look to avoid? The particular rig is a 1991 with power steering and looks to be in nice shape. It is coming from a 19' boat that was "Properly Winterized" but doesn't want to start this year. I figure I will give it a good look over and see if there is anything wrong I can see, I would like to hook it up to a hose and crank the motor to see what it sounds like and note if the crank case grows any oil.

 

[Bondo]

Ayuh,..... Sorta a pig in a poke,.... a compression test would be nice,....

maybe pressure test the coolin' system,.....

 

[Watermann]

Not sure I would pop for a donor boat that I want the motor from if I can't start it and hear it run. One thing to look for is if there's nice pristine oil in it. Be suspicious of that because most people who have nothing to hide don't want to spend money changing fluids on a motor they're selling. But if 20 bucks can fool people into thinking there's nothing wrong with the motor and give the impression they take care of their stuff then they will do that.