1977 85HP Head Gasket Replacement Question

[fdmsiv]

Can the gasket for the 115 HP of similar vintage be used on this motor? The reason I ask is the part numbers from Evinrude are different 85HP = 0318662 115HP = 0318358 but Sierra list the same part number for both engines 18-2959.

Thanks

 

[wilde1j]

Re: 1977 85HP Head Gasket Replacement Question

Same basic block. I would use the BRP gasket.

 

[iwombat]

Re: 1977 85HP Head Gasket Replacement Question

Just make sure you don't get the part for the XL shaft. The '77 XL shafts used the '78 and later powerheads.

 

[WizardIII]

Re: 1977 85HP Head Gasket Replacement Question

Boats.net (BRP dealer?) lists all these models:
http://www.boats.net/parts/detail/brp/B-0318662.html
The 85hp (318662) appears to be more than twice the price of the 115hp (318358).
Wonder why?

 

[emdsapmgr]

Re: 1977 85HP Head Gasket Replacement Question

The 85 hp model that year uses a small bore (different) piston than the 115/140's. That engine is 92.6 cubic inches, the others are 99 cube. The bore size difference is probably why the part number of the head gasket is different on the Bombardier parts lists. I would not rely on Sierra knowing the precise part. Opt for the Bombardier part. The fact that Bombardier probably sells very few of these head gaskets each year may be why they are so pricy.

 

[194269]

Re: 1977 85HP Head Gasket Replacement Question

I believe the last 92.6 cu/in block was used in 1973, the 1974 and later here 99.9 cu/in.

 

[WizardIII]

Re: 1977 85HP Head Gasket Replacement Question

My trusty 1977 Evinrude service manual (85793/115793) has the 85hp @ 92.6 cu. in. & the 115hp @ 99.6.
Good thought on the price difference but it sure seems like there are a whole lot of 85's around being worked on that would keep the cost in line.
Oh well....

 

[emdsapmgr]

Re: 1977 85HP Head Gasket Replacement Question

OMC standardized the block size for all hp models at 99.6 cube in 1979.

 

[194269]

Re: 1977 85HP Head Gasket Replacement Question

I can't argue with a trusty Evinrude service manual, I left OMC in '73 and don't have any manuals beyond that. Always thought they standardizes engines in '74 when they went to the larger rods.