Force 120 - had a lot of water in gas, now low compression. What would you do?

[mattsmall1972]

My buddy has a 1995 Force 120 Hp on his boat. Unknowingly, we went out to the water with a *ton* of water in the gas. Had a very hard time starting it and keeping it going. When we finally realized all of the water in the gas, we switched to a portable fuel tank and got it out on the water. The thing would not idle very well though.

On getting back in, buddy took it to a mechanic who says that it has low compression in two cylinders. I haven't see it personally. My question is, what would you do? Let's assume that the diagnosis is correct. Is it likely that the cylinders are badly scored, or something else? I saw a posting on this site about swapping out pistons without removing the powerhead. Might this be a good way to go to keep repair cost down?

I'm jus trying to think of the possibilities here.

 

[foodfisher]

Re: Force 120 - had a lot of water in gas, now low compression. What would you do?

Mechanic, buddy,you. too many peeps . I would test compressions myself and if 2 adjoining cyls are truly low , pull the head and look for bad gasket. Also would install a water seperating fuel filter.

 

[jerryjerry05]

Re: Force 120 - had a lot of water in gas, now low compression. What would you do?

Your still gonna have some water in the system.Drain the carbs.
Do like Food suggests and do a comp test.
Post the results.Did the mechanic give you the comp results?

 

[Jiggz]

Re: Force 120 - had a lot of water in gas, now low compression. What would you do?

Assuming the mechanic is truthful Personally this will be my course of actions:
1. Verify compression again and if the difference is more than 20 PSI time to open and inspect (if difference is less than 20 psi try spraying fuel-oil mix into the said cylinder and then try the comp test again. If the difference persists, open and inspect.
2. Remove head and check head gasket, pistons and cylinders

Post pics and then we'll discuss the nest step

 

[mattsmall1972]

Re: Force 120 - had a lot of water in gas, now low compression. What would you do?

Will get to that as soon as I can.

 

[General Quarters 74]

Re: Force 120 - had a lot of water in gas, now low compression. What would you do?

Will get to that as soon as I can.

The compression was 115-120 lbs in three cylinders and 40 lbs in one.

 

[jerryjerry05]

Re: Force 120 - had a lot of water in gas, now low compression. What would you do?

40's BAD.
General, you Matt in disguise?
Pull the head and look?

 

[mattsmall1972]

Re: Force 120 - had a lot of water in gas, now low compression. What would you do?

General is the buddy who owns the boat.