Merc 120 engine replacement to newer.

[Fordiesel69]

Well my quest in finding a 6 bolt rochester type manifold is drawing NOTHING!!! So I have found several 120 and 140 that are newer for $300-400 which is what a manifold costs. So my question is how hard it is to use a newer style engine.

I have a 1974 Merc 120 w/ MC-1 drive, and most engines I have found are from late 80's with MR drives or alpha 1's. How hard is it going to be? Do I just need to swap the coupler?

 

[Bondo]

Re: Merc 120 engine replacement to newer.

Ayuh,... Neither the flywheel cover, nor the riser will line up between the MC-1, vs. Alphas...

 

[Fordiesel69]

Re: Merc 120 engine replacement to newer.

So bottom line it won't work, or I need to swap some stuff over? Please confirm. Thanks.

I assume maybe I would need to swap over the flywheel cover, flywheel, coupler, and exhaust elbow?

 

[8595transam]

Re: Merc 120 engine replacement to newer.

I just replaced my 84 merc 140 with a 76 merc 140. The 84 block was cracked from the previous owner not winterizing properly. All I had to do was reuse my original bell housing,swap the harness over, re-install my exhaust riser from the 84 to the 76 motor. Hope this helps some.

 

[Fordiesel69]

Re: Merc 120 engine replacement to newer.

I was concerned about the flywheel weight, flywheel housing, starter and coupler. The rest I think I can make work. I can get an engine for the price of a manifold.

 

[cedarjunki]

Re: Merc 120 engine replacement to newer.

I was concerned about the flywheel weight, flywheel housing, starter and coupler. The rest I think I can make work. I can get an engine for the price of a manifold.

the exhaust elbow is different. you would then need to find the exhaust pipe and rubber boot off of the newer style, and change everything from where it bolts to the gimble.

where do you live???


also i believe the throttle controls are different.

 

[Fordiesel69]

Re: Merc 120 engine replacement to newer.

Erie, PA

Sounds like a real disaster then.......

I can understand why finding a replacement manifold was so hard. It must be a very special year and design. Why Merc found it necessary to change the designs and screw everyone over is beyond me.

 

[cedarjunki]

Re: Merc 120 engine replacement to newer.

Erie, PA

Sounds like a real disaster then.......

I can understand why finding a replacement manifold was so hard. It must be a very special year and design. Why Merc found it necessary to change the designs and screw everyone over is beyond me.

actually.... i cant undersand why its so hard to find one.....

you need the manifold that uses the studs in the head rather than the bolt through right?? there a dime a dozen used around here....


new here..http://www.marinepowerservice.com/BoatingStore/browse_detail3.cfm/productID/41547.cfm

http://www.oscomotors.com/catalog/catalog4.asp#

but another option would be to upgrade a little bit and use a manifold from a 140..very easy if you have a boat yard near by, would need the manifold, the riser (the riser is common on 4/6/8 cylinders up too mid 80's) and the boot since its a little larger in diameter. the price of a new one is hella scary but can be done fairly cheap off of ebay.

are you looking for new or used?? a yard very close to me gets 100....uch :/ looks around 30 bucks to ship ups