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Jason, Marine Mechanic
Category: Boat
Satisfied Customers: 16085
Experience:  Degree in Marine Technology. Gas and diesel marine mechanic.
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Thanks, Jason. I'll keep you abreast of what goes on. Get

Customer Question

Thanks, Jason. I'll keep you abreast of what goes on. Get some sleep! I'm packin' it in. You have a fascinating career... thx. Dave
Submitted: 2 years ago.
Category: Boat
Expert:  Jason replied 2 years ago.

Sounds good Dave. Just let me know if you have any further questions on the issue.

Good luck!


Customer: replied 2 years ago.

Hey Jason- it seems that the sellers tested the boat with 22" props and it reached 5200 rpm -- of course they didn't tell me the top speed of the boat with that set up... but anyway, I'm going to have 'an engine guy' take a look at this thing. How does one determine if the engine is putting out enough power.... I'd imagine a compression check of each cylinder; what else is typical that should be done? I'll probably have the phototachometer assessment, too. thx

Expert:  Jason replied 2 years ago.
Hi Dave. A compression test is the very first thing. A like new engine will come in at 180 psi. used but good 140 to 160 psi. worn but still life left 120 to 140 psi. Under 120 psi will still run and make good power, but is nearing the end of it's life. Anything under 100 psi indicates mechanical damage or a worn out engine. Checking timing advances would be the next step. Fuel pressure with the boat at top speed would be the next check after that. Hooking up a scan tool and reading live data looking for a bad sensor would come after that. If the engines are still down on power and all of the above looks okay. The inejctors would come off and get sent out to be flow tested, and to see if any of them were clogged up.