1979 Johnson 6hp low compression Part 1

1979 Johnson 6hp low compression Part 1
Facebook purchase, did I make a bad buy?

[@fleetwin1]

These are some of the best engines produced by any manufacturer. A head gasket failure is not uncommon, because there is no metal sealing ring around each cylinder. Doesn't look like it was every overheated, am guessing the pistons and cylinders look OK. I'm confident a new head gasket is all it will take to bring this engine back to life for another 50 years.

[@woodysgarage469]

Yep, it has been running good on the new head gasket.

[@fleetwin1]

@@woodysgarage469 Cool, you got a real bargain at $50 for sure. Take good care of it, will last your lifetime for sure

[@trevor4pleasure569]

Low compression new rings hone maybe reborn plus size positions and rings

[@TheArrow1100]

The coils fire at the same time . called waste spark timing . one piston is BDC waste spark . the other a TDC dose the work. Compression you felt was two stroke crank case compression. With the bad head gasket it just bled off between the two.

[@woodysgarage469]

Do you think I'm on the right track? Should have the gasket in a couple of days.

[@TheArrow1100]

@@woodysgarage469 If all else is good you are on your way

[@trevor4pleasure569]

Wabble socket remove the lower bolts

[@tmapaman7080]

I have this same motor. worked great for awhile then stopped starting with pull. I cleaned out the carb and then tried what you did at 7:53 with the drill start, it ran fine at high rpm, with a little lag in the throttle, but when I try to go to a low power setting at all she just won't go. I am confident everything in the carburetor is clear. any ideas?

[@woodysgarage469]

How's the compression? Plugs good?

[@tmapaman7080]

@@woodysgarage469 checked the compression, I had about 30. I took off the head and whaddya know I had a breach that looked pretty much identical to the one that you had. Gonna pick me up a new gasket, what's the one that you got?

[@woodysgarage469]

@@tmapaman7080 I'd look for an OEM Gasket, or Sierra brand. Should be good.

[@woodysgarage469]

@@tmapaman7080 One other thing. Maybe get a new impeller kit, head gaskets sometimes go when over heated.

[@tmapaman7080]

@@woodysgarage469 I know what happened when it went out, which makes sense. I ran over a plastic shopping bag at full speed so the prop cavitated and revved way higher than it should've. I guess it won't hurt to check. The gasket comes in monday

[@trevor4pleasure569]

Rings

[@nitroneal489]

Those are marine plugs

[@woodysgarage469]

Thanks Neal. What year did they start using them?