pitted cylinder head

[aqueduct]

Hello everyone new to iboats here. Recently I acquired a decent lil 1996 Johnson 48 spl.I did a compression check and the top cyl measured 135 and the bottom 132 I was happyBut thought I would give it some tlc since it is 17 years old. I rebuilt the carbs the fuel pump and the primer and replaced all fuel lines. I decided to remove the cylinder head for inspection just for **** and giggles and I found the head to be pitted pretty good especially below the bottom cylinder . The gasket had not failed but appeared it would have soon. I cleaned the surface and filled some of the major pitting with devcon. Then I sanded down on a flat surface and did the straight edge with feelers and found the surface to be flat. My questions #1) Is the head suitable for reuse based on pictures and description.
# 2) If not can I machine it down to remove the pitting? if so how far is max.
# 3) The third option I found is sum used heads on E-Bay But they are from earlier models ie 1992
and look exactly alike with the exception of the thermostat housing.

thanks for any advise.

 

[F_R]

Re: pitted cylinder head

It appears that most of the pitting is in the water jacket areas, which is not a big deal, but I do see a little bit where the gasket must seal the combustion chambers. Personally, from what I can see in the pictures, I wouldn't be afraid to re-use it. As long as the pit is real small and surrounded by good metal, it should not be a problem.

 

[Bosunsmate]

Re: pitted cylinder head

I as above would use the current one you have.
The 92 and 96 use the same headgasket but i wouldnt know about the recess though in terms of the piston travel and smacking the sparkplug

 

[aqueduct]

Re: pitted cylinder head

Wow thanks for the quick response . I was thinking the same thing regarding the pitting but do you know what model year head's would be interchangeable because the one I found is near perfect without pitting and at a great price. The pic with the square shaped thermo housing is mine the one im interested in is round and notice the deck on that head smooth as a babies bottom

 

[Bosunsmate]

Re: pitted cylinder head

Interchangable are only the ones with the same part number but thats not saying others wont work.
That one has a completely different internal thermostat, its likely nothing else would be different and it may work just fine. The problem would be if they had changed some other set up in the water cooling between 92-96 which would render the 92 thermostat system useless.
But if you tried it and checked it didnt overheat then you would have a nice head at the great price.

 

[aqueduct]

Re: pitted cylinder head

Hey thanks again for the advise . I think for forty bucks I'm gonna just give it a try

 

[racerone]

Re: pitted cylinder head

There were issues with the fit of the cowling in the area of the thermostat housing.--The square thermo housing is wider at the slot for the air intake.----In this case you are going to an older head and it is NOT a problem.-Should work.