225 Johnson with 1 dead cylinder

[Dexloy]

225 hp johnson 2001 very clean motor.

I ran a compression check and came up with 110 in all the holes but one it was at 10 so I pulled the head and inspected the cylinder and found the following:

Head gasket was clean and no apparent leaks
No cracks or scaring in block, head or piston
The hole with low comp was discolored brown around 1/3 of the cylinder looks kind of like rust, like the ring is not touching the wall in that area. It also had less carbon build up than the others so I would guess it has been down for a while.

My thoughts are that I have a piston with a broken/collapsed ring and just got lucky that there is no wall damage. This motor was given to me so I have not ran this motor and know little about how/what happened.

What next? Pull the power head and remove that piston? Should I replace the rings in all cylinders? The motor has very low hours on it so the bearings have lots of life left. I don’t care so much about cost or time but no need to be wasteful and I am going to do it my self so if there are things that are hard to do at home and don’t need done, Id rather not.

Also what do I need to order, is there a rebuild gasket kit? Any advice would be great. Thanks.

 

[WillyBWright]

Re: 225 Johnson with 1 dead cylinder

If it were mine, I'd put the head back on with the old gasket (with sealer) and do a thorough decarbonizing. Steps are in the FAQs. Don't run it in the water, just on a hose til it's warm. Then treat, maybe a few times if necessary. Go from there, but put a new head gasket on before venturing out onto the water. Hopefully the decarb will loosen the rings. If not, at least you didn't waste money on a new head gasket.

 

[Dexloy]

Re: 225 Johnson with 1 dead cylinder

I ran a .002 feeler gauge around the bad piston and I could feel the ring gap. The discolored area starts at the ring gap. I can push the gauge past the ring in that area but not anywhere else and not in any of the other pistons. I sprayed decarb stuff directly there and shortly after that it was harder to get the gauge past the ring, lets hope it will pop loose.

 

[tashasdaddy]

Re: 225 Johnson with 1 dead cylinder

prop the engine up and soak it.

 

[Dexloy]

Re: 225 Johnson with 1 dead cylinder

Thanks a ton!! started right up and the ring came free. 110psi just like the rest now.

 

[Dexloy]

Re: 225 Johnson with 1 dead cylinder

Do I need any thing besides a head gasket? like sealant or o-rings, it looks like there is a small red one at the bottom of the head.