Replacing head gasket? 67' 9.5

[thx997303]

The previous owner of this engine had the head off of this motor at one time, and didn't put a new one on.

So, I am going to replace the head gasket.

Can I do this without removing the entire power head?

Seems like I could easily just remove the head, replace the gasket, inspect and retorque.

 

[F_R]

Re: Replacing head gasket? 67' 9.5

You are correct, no need to make a hard job out of it. And powerhead removal is a hard job that will have you inventing new words.

 

[thx997303]

Re: Replacing head gasket? 67' 9.5

That's good.

I have a bit of a pop/sneeze issue going on.

It runs well, then starts to do the pop/sneeze, and when I disconnected the plug to the bottom cylinder, it ran worse, but when I disconnected the top cylinders spark plug, it died completely.

That and the previous owner had disassembled the engine and reused the head gasket, makes me wonder if I am having the problem because of the head gasket.

Carb was just rebuilt, points and condensers changed, need to adjust the carb, replace the head gasket, and time it.

See how it runs then.

I might add that I have not actually had this out in the water yet. Only had it in a storage container full of water.

I have heard that these motors like to idle rough while in tanks.

 

[Rick.]

Re: Replacing head gasket? 67' 9.5

Not a bad idea to change it but that isn't going to help your problem. If you disconnect one wire and she dies that means that's the only plug that has fire. You have an ignition problem. I would pull the flywheel and start checking points, plug wires, even plugs. That sneeze could just be your low speed needle adjustment but wouldn't worry about it till you have fire on both plugs. A simple compression check should tell you if the head gasket is in need of replacement but that is one gasket I would not re-use. Best of luck. Rick.

 

[thx997303]

Re: Replacing head gasket? 67' 9.5

Rick, when I disconnect the plug on the lower cylinder, it immediately begins running horribly. But it still runs.

When I disconnect the top cylinder, it dies.

To me, and I don't know, it just seems that the bottom cylinder IS firing, but not performing properly.

I replaced the breaker points and condensers, new plugs, and rebuilt the carb.

I need to replace the head gasket, and do a compression check first just so I know what is going on, then I want to put it in the water and adjust the carb properly, and go from there.

Seems like a coil might do it. Probably replace them, but dang it I went and returned the harmonic balancer puller and the torque wrench.

Guess I better go get em again.

 

[Rick.]

Re: Replacing head gasket? 67' 9.5

You should buy yourself a spark tester with an adjustable gap that will allow you to see the spark jump and view the quality of the spark as well. It does sound as though your getting some spark on the lower cyl. but not enough to keep it running. A comp. test is always the first thing I do so I can make an informed decision if the motor is worth buying parts for. If it's bad, a head gasket is cheap but if it has a new head gasket and poor compression I'm usually done with it right then and there. Best to Adjust your carb. at home in a barrel and then fine tune it on the water but your not ready for the water yet. Let me know how it goes. Rick.