76 6HP Johnson

[stator1]

I have a 6 that has been giving me a hard time. It died on my son last weekend and I found water getting into the cylinders. I changed the head gasket and exhaust manifold gaskets. The thermostat was stuck open so I changed that too. It took many tries at re-torquing the head bolts but I'm sure that I don't have any water in the cylinders now. I kept checking the plugs and they appear dry, no water. But now the lower cylinder plug looks really dry ,not much gas but tan looking plug, the top plug is always soaked with gas. I pulled both plugs and layed them on the block I have a very nice blue spark on both plugs. Is it possible that the carb could be dirty and causing all the or most of the gas to go to one piston and not the other? It has no power but idles great. Thanks for any pointers guys.

 

[tashasdaddy]

Re: 76 6HP Johnson

it only has single carb, so not to carb. check your compression. report back, pull the motor around six times and get reading.

 

[stator1]

Re: 76 6HP Johnson

I should have checked that. Your right..It was running great until the head gasket let go. I'll get back to you as soon as I can borrow a compression tester. Thanks a lot.

 

[stator1]

Re: 76 6HP Johnson

3 pulls 65lbs.
6 pulls 85lbs.
Both cylinders read the same. I think I need new rings. What do you think guys. Thanks for any replies.

 

[iwombat]

Re: 76 6HP Johnson

85lbs is decent enough. My guess is its not firing on the one soaked with gas.

 

[stator1]

Re: 76 6HP Johnson

I get a nice spark out of each plug. Well I think it's good, maybe it's too weak. Funny thing it idles great but no power. I'll check my points next. Not sure what else it could be. Thanks a lot guys. This is a great site. Hats off to the moderators!

 

[iwombat]

Re: 76 6HP Johnson

Firing across the plug gap isn't much of a spark test. You can build a simple spark tester for that thing with three nails, a piece of wire and a board.

Pound three nails through a board about an inch apart.
On the side with the points, bend the outer two nails inward so that the gap is 7/16".
On the head of the middle one, wrap it with a piece of wire. Ground wire from romex works great. You'll attach the end of this wire someplace on the block.
Attach your spark plug wires to the heads of the outer nails.

Now, you should see spark jump across the nail gaps to the center nail bright and blue when you pull.

 

[stator1]

Re: 76 6HP Johnson

iwombat I went out to the garage and made one with some large finishing nails and a piece of small plywood. You were right the top cylinder was not firing. That was a great idea to make a spark tester. Swapped coils, still no spark, checked spark plug wire it is ok, Condenser is about .22uF on my cap meter so there ok, Darn point on top cylinder are done..... Thanks again iwombat