1988 150HP Head Gasket Leaking after being replacd

[Power_Dr]

I had bad compression on a couple cylinders so I pulled the heads. There was a hole in the head gasket between two cylinders. I pulled the other side off as well and the gasket was really thin in a few spots. I put two new gaskets on and torqued them to 20 ft.lbs in three stages. When I started it up there was water leaking out around the head gaskets on both sides. The old gasket said right on the top "No Sealant" and they were black. The new gaskets were blue (got them at the dealer) and didn't say anything on them. Are you supposed to use any sealant on these is they don't say anything?

 

[oldboat1]

Did you resurface the heads? Sounds like some warping.

 

[Power_Dr]

I did not have the heads resurfaced. I think I am going to have to do that. Do you know if I should use any kind of sealant with this head gasket?

 

[oldboat1]

Might check with the dealer to see what they do in the shop with those gaskets. I routinely use OMC/BRP gasket sealer on all gaskets (light coat, spread evenly).

 

[emdsapmgr]

The ones marked "no selant required" are to be installed w/o any gasket sealer. If you've installed them correctly, then you'll need to check the flatness of the block and the face of each head. This flatness issue can come into play if the powerhead was ever severely overheated.

 

[racerone]

The heads are warped , all outboard cylinder heads warp,----Just the nature if an aluminum casting and warming and cooling cycles.

 

[SparkieBoat]

Get your heads smoothed, also ask the machine shop to record how much they had to take off and to shave each head the same. If they have to take off too much or you have had this done several times, you may have to use thicker head gaskets. No sealant.

 

[SparkieBoat]

also , go back ant retorque the head bolts after you run it good one time.

 

[emdsapmgr]

Agree with post #8!

 

[Power_Dr]

Thanks for the replies. I will check with the dealer to see if they use any sealant. I am going to have them resurfaced as well.

 

[Power_Dr]

I am going to take the heads to get them resurfaced. Do you think if I take the heads off and get them resurfaced I can reuse the gaskets that I just put on? or once they were torqued do I have to get new ones? These were just installed last weekend and torqued down and stated the motor for two minutes.

 

[emdsapmgr]

Head gaskets are a one-time use gasket. Get some new ones to be sure the job is done correctly.

 

[oldboat1]

Could save some bucks by resurfacing yourself -- sandpaper and a hard surface. Should be a bunch of threads on that. I use 400 grit wet/dry on the table top of my saw, moving the work around in figure 8 fashion. Takes a while, but know you're there when the mating surface is uniformly shiny.