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1993 390 CPMY 7.4 Mercruiser Engine issue
Posted: September 5th, 2018, 1:30 pm
by tkreager
Hi all,
Looks like my port engine is locked up tight, 550 hours, minimal use within past 5 years due to bad fuel related issues.
Any feedback is welcome.
Thanks
Re: 1993 390 CPMY 7.4 Mercruiser Engine issue
Posted: September 5th, 2018, 3:02 pm
by tomschauer
Its unusual for an engine to lock up at those hours unless....
Ran low or out of oil, oil not changed regularly and motor full of sludge, water in cylinders due to failed manifolds etc. Bad fuel will cause many issues but usually not a bottom end failure on a big block chevy. Do you know what caused it? Are you sure its locked up? (did you remove the plugs and try to turn it via wrench on the fly wheel)
Re: 1993 390 CPMY 7.4 Mercruiser Engine issue
Posted: September 5th, 2018, 3:46 pm
by Midnightsun
My guess is hydro locked. Pull the plugs and crank her over. You will see right away if it is hydro locked. May want to wear a rain coat.
Re: 1993 390 CPMY 7.4 Mercruiser Engine issue
Posted: September 5th, 2018, 7:20 pm
by km1125
When was the last time it ran?
Re: 1993 390 CPMY 7.4 Mercruiser Engine issue
Posted: September 5th, 2018, 10:16 pm
by Viper
Welcome aboard.
I agree with the guys. Unless you've done some diagnosis, don't jump to conclusions. Could be anything from dead battery, starter, slave solenoid, to hydro lock or worse. What have you done to assess the issue?