Motor surging and water in cylinder

[Gjgrant]

The motor is a johnson 235. It started to surge and when I took the spark plugs off there was water one of the bottom cylinders. The spark plug was coated with white oil and water. I am not sure if the surging is caused by the water in the cylinder or a carb running lean. I am guessing that the head gasket is bad and is lettting water into the cylinder. I checked the compression and it was good so I am wondering if there is a way to test the head gasket. I don't want of just throw money at it and hope that I get lucky.

 

[geoffwga1]

Re: Motor surging and water in cylinder

Sure sounds like the head gasket to me,though that size of motor is a bit outside my purview so I'll sit back and see what the more experienced members have to say.
Geoffwga1

 

[sutor623]

Re: Motor surging and water in cylinder

Sure sounds like the head gasket to me,though that size of motor is a bit outside my purview so I'll sit back and see what the more experienced members have to say.
Geoffwga1

Yea me too, for both of those comments.....

 

[itsaboattime]

Re: Motor surging and water in cylinder

You say you checked the compression and it was good. How good? The reason I ask is because if the head gasket is bad then you will not get good compression numbers. Those big motors have funny compression tests. Not like a 50 horse.
I'd pull the head. Regardless of compression you have to figure out where the water is coming from. It doesn't belong there. Fix that problem and then see if you still have a surging problem.

 

[emdsapmgr]

Re: Motor surging and water in cylinder

If the cylinder with water in it has good compression, it may not be a head gasket. Probably an exhaust system leak. Exhaust manifold leaks tend to affect the lower cylinders first. (the engine will pump any exhaust water back into the lower cyls.) You can get into a number of exhaust leaks on that engine. The inner and outer gaskets may have loosened with age, permitting water to leak into the exhaust chest when running. Retorquing the exhaust bolts may not help, since there are 6 inner manifold bolts that are hidden under the outer cover. Any of them can lose torque over the years. I've also seen casting porosity on the inner manifold, which will also leak water into the exhaust chest. (You can easily weld up the casting problem.) Probably the easiest is to just replace the head gasket first and go from there-probably worth trying first. If that does not fix the problem: Pulling the exhaust system on that engine is a bear-specifically when you try to line it back up during reassembly.

 

[Faztbullet]

Re: Motor surging and water in cylinder

Pull the head and inspect gasket and cylinder. If its the flat back 235 the inner exhaust plate could be rotten or if its the "bubble back" the inner gasket is likely bad or it has a cracked sleeve as these models have extremely thin cylinder sleeves/walls..