Troubleshooting guide for water in cylinders

[Chased2]

I recently purchased 18 cris craft cavalier with 3.0 omc. I am going thru and testing the reliability of the motor. Reason I ask is because the water pump housing in outboard was melted and in research it says may have overheated due to leaks in water jacket in exhaust. I hope that is not the case and I just want to make sure my cooling system and exhaust manifold and risers are okay. Thc

 

[Lou C]

That housing can distort if there is a lack of water flow up to the upper gear housing. You remove the housing & impeller. Then get a set of good fitting muffs and hook them up to a water source. Have someone turn on the water while you hold the muffs tight to the lower unit. You should see water spurt out of one of the openings in the impeller mount. If so then good if not you need to find out why. It can be melted and distorted water tube gaskets inside the outdrive. If so the upper & lower gear housings have to be split and the repairs made. Make sure you use good fitting flexible muffs. DO NOT try running it in a barrel that does not work on stern drives the water can’t get high enough for the impeller to prime. Impellers can only move water not air!
for the manifold & elbows you need to dis assemble and check water passages; if clogged with rust replace. The impeller is a very easy job on the Cobra

 

[Chased2]

Not sure what you are refuring to. Would that be in the housing where the rubber impeller is located? Or watch for water sperting out from somewhere else? I appreciate these forums so much . such knowledgeable people.

 

[Chased2]

Also need clarification with this. remove the housing & impeller. Thats the small plastic housing in the upper that is currently distorted it has a metal screen in there as well just to help me identify things.

 

[Lou C]

best advice I can give is to get a factory shop manual it will answer all your questions. Yes remove the small plastic housing, (3 bolts) behind that you will see 2 water ports, and a shaft that drives the impeller, water should come out of one of them when you hook up the muffs.

 

[Chased2]

Thank you so much Lou c for the time you took to explain . I replaced it and did the test and got column of water out pickup tube. I have water going thru the engine. I did buy the online manual it's been great. Its guys like you that spread the joy of boating and working on them as well.