1989 Force 50 Head Gasket Blown Again ???

[geoholt3]

I just got my 1989 Force 50 O/B and when I got it the head gasket was blown right where the two cylinders meet in the middle. I replaced the gasket and it ran great. I spent the day at the lake yesterday, and it ran like a bat all day. On the way back to the dock, I powered down the boat to an idle and it sputtered and died. The head gasket had blown in the same place again. Why is it doing that? I only used it once, and now I have to get another head gasket. Water seems to be circulating through it fine. Am I not supposed to run it wide open for long periods?

 

[Walker]

Re: 1989 Force 50 Head Gasket Blown Again ???

Maybe your head or your block is warped.

 

[geoholt3]

Re: 1989 Force 50 Head Gasket Blown Again ???

I had the head checked at the boat shop where I bought the gasket and they said it was perfect. The block also looks great. Does a warped head or block usually cause the gasket to heat up and burn through between the two cylinders?

 

[geoholt3]

Re: 1989 Force 50 Head Gasket Blown Again ???

Hi Walker,<br /><br />I just put a sraight edge across the head and you were right, it's warped. The block is perfect...but there is a gap around were the two clynders meet in the middle...right where the gasket burned in two. I could slip a postcard under it. I will have a little talk with my boat repair guy Monday. Can that head be machined?

 

[FlyBoyMark]

Re: 1989 Force 50 Head Gasket Blown Again ???

Put a straight edge on the block too and make sure your using the proper torq on the head bolts. I would make sure your using a good quality head gasket too and not some home made contraption. And as a last terrible thought, examine the head AND block for hairline cracks. Proper torq sequence is important too.(use some sort of marine head gasket sealer if possible.

 

[geoholt3]

Re: 1989 Force 50 Head Gasket Blown Again ???

Sealer??? They told me not to put a sealer on the head gasket. The gasket was a factory original. The block looks flush and perfect with no cracks, and I used the proper bolt pattern torque sequence. Are you sure about a sealer???

 

[FlyBoyMark]

Re: 1989 Force 50 Head Gasket Blown Again ???

There are special head gasket sealers and they are non adhesive. You said it "looks" good but did you check with a precision straight edge? Check your torq specs closely. I have found some manuels erronius in this area. As another thought, has the head been milled for higher performance? Did you by any chance "flood" start he engine?(hydraulic lock) While the head is off check the water passages for blockage(calcium or salt deposits), this will cause hot spots in the engine. I would again carefully check the area that "blows out" for uniformity. it only takes a few thausandths of an inch to make the gasket fail under any stress.

 

[FlyBoyMark]

Re: 1989 Force 50 Head Gasket Blown Again ???

I forgot to ask is burned through or blown through?

 

[geoholt3]

Re: 1989 Force 50 Head Gasket Blown Again ???

I have a great manual made by SELOC. The torque sequence from the manual makes sense too, as you would expect if you were torquing down any head. I had been cruising all day and was heading into port when it blew and quit. I was at full throttle and had just powered down for the slow cruise into dock. I'll get a better straight edge right now from the store and check the block a little closer.<br /><br />Thanks...

 

[geoholt3]

Re: 1989 Force 50 Head Gasket Blown Again ???

Burned and blown.

 

[geoholt3]

Re: 1989 Force 50 Head Gasket Blown Again ???

I could take a picture and show you if you have an E-mail address.

 

[moose211]

Re: 1989 Force 50 Head Gasket Blown Again ???

I THINK YOU MAYBE OVER HEATING CHECK YOUR THURM, AND IMPELL ER

 

[geoholt3]

Re: 1989 Force 50 Head Gasket Blown Again ???

My new heat sensor and alarm never went off. I tested them and they both work...but that's what I thought too..

 

[FlyBoyMark]

Re: 1989 Force 50 Head Gasket Blown Again ???

Moose is rite, your combustion chambers could be running high too.<br />You might be lugging or running the engine at too low of RPM's, this will give you the problems your having too...what is your RPM @ WOT and what is the redline and lower rpm envelope for your particular motor?<br /><br />Since the head is booggered up a bit I would get a quote on welding it(build up) and jus buying a new one. milling it could give you more problems with high compression and running two head gaskets is not a good option for your engine.<br /><br />ARE YOU USING THE PROPER SPARK PLUGS?

 

[geoholt3]

Re: 1989 Force 50 Head Gasket Blown Again ???

I don't have a Tach on the boat. Or a temp gauge. But it's on my list. I don't know the redline rating either.

 

[geoholt3]

Re: 1989 Force 50 Head Gasket Blown Again ???

The dealer said the plugs were correct.

 

[FlyBoyMark]

Re: 1989 Force 50 Head Gasket Blown Again ???

Get a tiny tach if ya can, cheap and simple to hook up

 

[geoholt3]

Re: 1989 Force 50 Head Gasket Blown Again ???

I will.

 

[geoholt3]

Re: 1989 Force 50 Head Gasket Blown Again ???

Milled the head, replaced the head gasket, got a tach, had a great weekend...thanks guys!

 

[FlyBoyMark]

Re: 1989 Force 50 Head Gasket Blown Again ???

Let us know what you spin'in up...