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did not mean to stop a question I had just erased a suggestion after I read your note a second time but my bottom signature remained no offense meant
We all learn from questions and answers that solve problems
anyhow…. have you pulled the head gasket yet ?? but it is odd that compression #s are still so high if it is a leaky gasket
Joining AOMCI has priviledges 🙂
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Unfortunately, the 75hps are more susceptible to powerhead damage than the regular 70 models, so I’m guessing there is internal bearing/journal damage. For now, I would recommend reinstalled the head/gasket (if it looks OK), then removing the gearcase. Once the gearcase is off, you can start the engine to expel the water and clean off the bearings without worrying about additional water entry or impeller damage. Once the powerhead has been somewhat preserved, you can take your time pulling it apart.
And yes, it is best to pull the powerhead off when trying to remove that exhaust cover mess, you will probably encounter a few seized bolts.
Sure hope I am wrong about the bearing/journal damage, but I fear not…1 user thanked author for this post.
The 75hp powerhead is ported differently, and may have higher compression, the carbs and WOT timing specs may be different also. These are high performance engines that really don’t do well on conventional non performance hulls…They don’t have a lot of mid range torque, and are meant to be wound up….The engines usually suffer slow detonation damage when bogged down on conventional hulls, often over propped.
The exhaust covers on this engine are a complicated arrangement of water passages and exhaust passages meant to help “scavenge” more power out of the engines through “exhaust tuning”…These covers often get loose, allowing the cooling water to mix with the exhaust, usually ending up with water in the powerhead. Sometimes, piston skirts will break and crack/poke a hole in the crankcase into one of the exhaust cover water passages. In any event, seems doubtful you will find too many salvageable parts when you pull the powerhead apart, journals are most likely damaged. But, you never know….Once the powerhead is pulled/stripped, it is certainly worth the hour it will take to pull the powerhead apart and inspect it, you never know….
You don’t need any controls to run the engine on your stand, provided your stand is strong enough and won’t tip/break when you start the engine. I would remove the gearcase, and attempt to start it anyway. Simply connect a large battery cable to the engine ground, and a positive cable to the hot side of the solenoid. A little jumper lead from the hot side of the solenoid to the yellow/red lead on the solenoid terminal will engage the starter. Run the engine for a few minutes with no gearcase or water until it heats up enough to expel any left over water inside. Let the engine cool down then run it again….
Again, only attempt this if the engine is securely bolted to a sturdy stand that won’t tip over when the engine starts. Make sure there are no fuel leaks that might spark up a fire as well….
I guess I really should have started my reply with this question: Are you sure the water isn’t coming from a bad fuel supply that has water in it??1 user thanked author for this post.
If you decide to start it on a stand, make sure the control box with the key is plugged in or you have a way to shut it off if the harness is unplugged. Contrary to popular belief, it will start with the wiring harness unplugged!
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