1978 Johnson 140hp running rough. Need advice

[Bman2895]

Ive had people say you just beed to smooth out the high spots and run it? And they are abundant, but if i can reuse this set of heads id rather.

 

[jimmbo]

Those pits will also likely fill with Carbon, creating Hot Spots leading to Detonation, which I suspect had something to do with the last Ring Failing. I suspect that this engine has had this Dance before

 

[Bman2895]

So no saving that head?

 

[saltchuckmatt]

In my opinion, not enough picture to really tell but others may disagree...but if it is savable, besides saving some "clams" a figure 8 pattern on a dead flat surface with some very large 120 grit sandpaper will make it pretty damn flat.

Mix that with new gaskets, and torquing them correctly gradually 2 or three times and you may be in business.

Are you retired or young and out of control....possible broke or rich...

Question goes down the rabbit hole.

 

[jimmbo]

I would Not reuse that Head. However, it is your Motor and your Money, so you can do whatever you want.

 

[Bman2895]

Definitely doing things on a bit of a budget. I can try and find another head, but it seems a bit hard to get a starboard head

 

[Mc Tool]

Id give it a go , pien down as much of the high bits so to push them down ....not fold them over , bit of a wizz with a wire wheel ( to remove any loose bits ) and Bobs yer auntie .
Tell ya what .....most of the peeps telling you not to use it .....would if it was theirs and another replacement was proving hard to find .
I have seen worse

 

[jimmbo]

There Tens of Thousands of those 99 inch 135s and140s out there. Shouldn't be too hard to find a Head

 

[saltchuckmatt]

Definitely doing things on a bit of a budget. I can try and find another head, but it seems a bit hard to get a starboard head

Send us a better picture from farther away perhaps.