Evinrude Head Damage

[hawkman222]

I have a 1975 75HP Evinrude I'm rebuilding, model# 75543B. I'm in pretty good shape, reboreable cylinders, I found some good used rods & a crank, but the head has some speckling on it from the #2 big end rod bearing that went bad. I can't find a good used head for this motor to save my life! I took it to my local machine shop and he didn't think it was too bad. He thought .020" planed off would clean it up. If I get it planed down and use a low compression gasket with it, will I be OK? Are there other options?

 

[Dhadley]

Re: Evinrude Head Damage

Don't cut that head more than .010" and only that much if you can confirm that it hasn't been cut before. There are several places to look for heads. Try Jack at Superior Marine at 800-338-9281. Tell him I said hello. And for him to get back to work!!

 

[hawkman222]

Re: Evinrude Head Damage

Don't cut that head more than .010" and only that much if you can confirm that it hasn't been cut before. There are several places to look for heads. Try Jack at Superior Marine at 800-338-9281. Tell him I said hello. And for him to get back to work!!

 

[hawkman222]

Re: Evinrude Head Damage

It's going to take more than .010" to fix it. I guess that means it's not fixable! I've found a couple of heads that will fit it, but they are from later models that have the coil mounting posts cast into the head. Mine just has the seperate coil mounting bracket that holds the coils and powerpack. I'm afraid I'll end up having to buy a bunch of new electrical items if a get one of these newer heads. Will I need different coils and powerpack if I go this route?

 

[emdsapmgr]

Re: Evinrude Head Damage

Two suggestions for locating a replacement head: Boat Recyclers of Wilminton (North Carolina) advertises a lot on Ebay-they tear down tons of older outboards and may have a used head. You can find them on the web. Sea-Way marine in the Seattle area buys up new NOS parts from other dealers and has a huge inventory of obsolete OMC parts. They have an 800 phone number-call information for the #.

 

[hawkman222]

Re: Evinrude Head Damage

Thanks for the leads. I'm still not sure why taking a little more off and using a thicker gasket won't work. I know the manual says no more than .010", which is a pretty good reason, but you'd think a thicker gasket would compensate. Are the low compression gaskets not much thicker? Would I be compromising the integrity of the head?

 

[Dhadley]

Re: Evinrude Head Damage

Can you still get the thick gasket? If so, you're set.

You can use the newer head and cut off the coil mounts that you don't need. You'll have to fabricate something for the two rear bolts of your electrical plate. But it can be done.

 

[hawkman222]

Re: Evinrude Head Damage

Sierra shows a low compression gasket for this motor in their catalog, but the OMC (BRP) literature doesn't show a low compression gasket. It shows a 'High Preformance Kit" and a 'Low Compression Kit' all using the same gasket. It looks to me like they sold different heads instead of different gaskets.