1989 Johnson GT150 - Mechanic?

[JonM]

This motor is on a project bass boat. I've been told the motor is blown, but don't have any other details.

I've drained the lower unit oil and didn't see any red flags. I've also sprayed some lubrication into the cylinders, and the flywheel rotated pretty easily. I think I had the plugs out when spinning the flywheel by hand if memory serves me correct.

If you know of a great OMC mechanic who has a passion for working on older OMC motors like this in Minnesota or the Dakotas, please let me know.


Thanks guys,
Jon

[perfmarine1]

Get a compression gauge and do a compression check cranking. You can rent or barrow one from autozone. That will tell you if it is blown. Just leave the key off and use a remote starter or jump the solenoid. So you don't fry the ignition system.

[MrG]

Make shure you have the throttles wide open to get maximum air into cylinder for 3 to 4 max hits of comp any more is just building press up many just run till max press is stabilized on gauge my quick check dosent matter of engine 2stroke or 4 cycle air dosent get ther if carbs / throttle body is closed under a vacuum is also using crankcase charge lambrith seal check hold hand over carb for hard vacuum as well ����

[FMP]

Fire it first to get that lub you sprayed burned out of the bores. It'll give you a false higher healthy value.

[MrG]

.060 inch =1.524 millimeter

[racervboat]

.060 inch =1.524 millimeter

? whats that about

[MrG]

Oops posted on wrong thread was about fuel starvation on loopers the seats have to be opened up to this spec for adequate fuel supply @ higher rpm ��

[racervboat]

Ok. So blown motor = 1.524 mills. HAHAHA