Replace Head Gaskets 77 115 Johnson

[whitejamie99]

Just took the heads off. Starboard side head gasket blown at top. <br /> <br />Is there any other prep that needs to be done to either the head surface or the block before I put it back together? Also should I pull out the deflectors and check them while I have the heads off? Do I need to do anything special with head bolts other than proper torque?<br /> <br />Go Spurs Go<br />Jamie

 

[mikeyzx2]

Re: Replace Head Gaskets 77 115 Johnson

you should wet sand the heads there's a method with glass and figure-8 motion I read about but haven't ever done. look it up.

 

[Solittle]

Re: Replace Head Gaskets 77 115 Johnson

Don't just check the deflectors - replace them while you have the heads off. One less thing to think about.

 

[whitejamie99]

Re: Replace Head Gaskets 77 115 Johnson

Found the figure 8 wet sand post. What do you use to "wet" the sandpaper. <br /><br />Jamie

 

[whitejamie99]

Re: Replace Head Gaskets 77 115 Johnson

Got the deflectors and installed them except that about 1/4" is still sticking out. Cant get them to go in to save my life. What happens if I cut this last bit off flush with the metal? Will they still work or not?<br /><br />Jamie

 

[R.Johnson]

Re: Replace Head Gaskets 77 115 Johnson

Trim the deflectors, and forget about lapping the head.

 

[BoatBuoy]

Re: Replace Head Gaskets 77 115 Johnson

Agree w/R.Johnson. You might need to lap(mill) the head if it overheated. Otherwise, just clean any old gasket fragments from the mating surfaces.

 

[whitejamie99]

Re: Replace Head Gaskets 77 115 Johnson

Thanks guys. Did some light sanding on the heads with med grit sandpaper on a piece of glass. The starboard head had overheated and had a few high spots but after a bit of sanding it looks smooth and level. Torquing down head bolts tonight and running compression tests right afterward. Will update after job is finished.<br /><br />Jamie

 

[wilde1j]

Re: Replace Head Gaskets 77 115 Johnson

Retorque after about 10 hrs running time.