1967 Johnson 9.5 Gasket leak?

[superflydudebike]

I was winterizing my motors and noticed water accumulating on top of engine directly behing flywheel (place where that coin-shaped serial number plate should be, happens to be missing on my motor). I wiped it away and it reappeared. I can only describe the gasket as the one that is at the very rear portion of this engine where plugs are located (head gasket?) and is somewhat shaped like an 8. The gasket is on a vertical plane. I realize that my lack of knowledge is showing here, but it seems like a very small trickle of water is seeping from this gasket and pooling on top of engine. How should I rectify this? Is this a huge task? This is a recent development. Could this be causing water to seep into cylinders as well? I was planning on selling this motor in the spring, so is it best just to sell it as is and inform buyer of problem rather than tackle this myself? Should I at least take out spark plugs in case there is water in cylinders? I have replaced a water pump on a car before, but outboards are a new game for me. Also, where does one obtain gaskets for lower unit gearcase drain plug? Are O rings used? Are they pretty universal, or do I need to drain oil and then match up gasket at hardware store. I suppose rubber as material is out.

 

[iwombat]

Re: 1967 Johnson 9.5 Gasket leak?

Head gasket is correct. It's a pretty easy job and the gasket itself isn't that pricey. You probably want to plane the head while it's off. Sandpaper and a piece of glass (or another flat surface) is all you need for that.

The lower unit washers are plastic. You can get them by the handful at your dealer. Some other stores sell them also.

 

[F_R]

Re: 1967 Johnson 9.5 Gasket leak?

It may or may not be leaking inside the cylinders a well. You should replace the gasket and run the motor again before putting it in storage, just in case.

There were 3 kinds of drain plug seals, gasket material stuff, soft plastic, and o-rings. Replace in like kind, except the plastic ones replace the old gasket material stuff.

 

[iwombat]

Re: 1967 Johnson 9.5 Gasket leak?

The '67 is the plastic - at least it is on mine.

 

[superflydudebike]

Re: 1967 Johnson 9.5 Gasket leak?

Can't I just make my own gasket out of gasket material left over from water pump installation (made own gasket at that time, but material is very old) or what about that form a gasket stuff that comes in tubes? Are these 9.5 engines good? I just upgraded to a 15 HP motor and the guy that I bought it from told me that the carb design on the 9.5 is poor compared to subsequent carbs. Thoughts? I now have three motors: 1972 Rude 6 HP, 1967 Johnny 9.5, and 1986 Rude 15 HP (Canadian). Want to sell off weakest in spring. Johnny has seen the most use, does not run as smooth as others, and it was my cheapest investment ($200). Perhaps I answered my own question.

 

[superflydudebike]

Re: 1967 Johnson 9.5 Gasket leak?

There were 3 kinds of drain plug seals, gasket material stuff, soft plastic, and o-rings. Replace in like kind, except the plastic ones replace the old gasket material stuff.[/QUOTE]

Are you saying that O rings should be replaced with O-rings and gasket material with same, but plastic should be replaced with something else?

 

[iwombat]

Re: 1967 Johnson 9.5 Gasket leak?

O-ring -> O-ring
Plastic -> Plastic
Gasket -> Plastic

There's nothing inherently wrong with the 9.5s, but parts are getting scarcer and scarcer. That mid '80s 15hp will have cheap parts available as far as you're going to want to keep it.

 

[F_R]

Re: 1967 Johnson 9.5 Gasket leak?

The reason we can't say for sure which kind is in any particular year is because somebody may have changed the entire plug & seal assembly. They do come that way, as well as just the seal.

 

[superflydudebike]

Re: 1967 Johnson 9.5 Gasket leak?

What about the head gasket? Can I fashion my own or will I have better success with preformed gasket from dealer?

 

[iwombat]

Re: 1967 Johnson 9.5 Gasket leak?

You can not make your own head gasket with any expectation of success.

 

[superflydudebike]

Re: 1967 Johnson 9.5 Gasket leak?

Thanks for all of the feedback. Sounds like I have a small project on my hands.

 

[superflydudebike]

Re: 1967 Johnson 9.5 Gasket leak?

I have a few concerns about replacing the head gasket. Is it worth trying to to tighten the bolts a bit to see if this will stop the leak? It is only leaking a small amount at very top of gasket. How can I tell if there is any water in the cylinders? I have been able to locate a head gasket (Sierra) via internet (about $15 with shipping) and have read about installation. Do I really need a torque wrench for this as suggested or just snug the bolts and avoid overtightening?

 

[iwombat]

Re: 1967 Johnson 9.5 Gasket leak?

You need a torque wrench, and you must tighten in the dictated sequence incrementally. Snug them up , then tighten to 1/2 torque, then 3/4, then full, always using the supplied sequence in the manual. Once the gasket blows it's all over. You need a new one.

 

[superflydudebike]

Re: 1967 Johnson 9.5 Gasket leak?

Middle bolts first and then tighten adjacent bolts essentially to upper and lower ends of cover, correct? I believe I counted eight bolts. Apply a penetrant before loosening bolts? How can I tell if I have water in cylinders?

 

[iwombat]

Re: 1967 Johnson 9.5 Gasket leak?

Your plugs are probably the best indicator of that. Does one look like it's been steam cleaned? Also, when you pull the head you can usually tell by looking at the gasket where it's blown.

 

[superflydudebike]

Re: 1967 Johnson 9.5 Gasket leak?

Pulled plugs last night. Both looked pretty normal to me. I pulled on rope a few times to see if any water came out of spark plug holes. No sign of water.

 

[superflydudebike]

Re: 1967 Johnson 9.5 Gasket leak?

I'm able to secure after market Sierra head gasket for just under $15 bucks. Do they make quality products? I searched all over the internet and called local part suppliers and the best price was from marine dealer close to me. Also, I'm getting shop manual from local library to read up on project beforehand.

 

[iwombat]

Re: 1967 Johnson 9.5 Gasket leak?

Sierra gaskets are just fine.

 

[superflydudebike]

Re: 1967 Johnson 9.5 Gasket leak?

I'm glad that I went back to check where the leak was conimg from before proceeding with a head gasket change. Previously, I had noticed the leak in the dark and I was unable to tell the exact origin. I decided to try to pinpoint the leak and found that the theromostat housing cover gasket was leaking. A much easier fix. I was able to fashion a gasket out of some gasket material that I had on hand. It did not hold w/o gasket sealant, but it held when sealant was used in conjunction with the gasket. I had called the marina for the gasket, but they were closing in a few minutes so I decided to use the stuff that I had. Plus, the parts guy told me that there was less pressure on this gasket than a head gasket.