1994 150 Magnuim 2,5L EFI-damage on one piston.

mxzer29

Cadet
Joined
Jul 15, 2008
Messages
27
Hello here is the scoop...
Motor shut down twice..think the oil pump quit-started missing....Did compression test 5 out of 6 cylinders all at 120 strong...middle cyl on right hand side 0...took head off, peice missing out of piston..looks like might be a peice of cylender sleeve where the port is...
weird thng is that the cylinder walls are not marked up??? there was debree on spaark plug..head has some marks....
Can I just do the one cylinder put a new piston and rings aand sleeve it if needed...
I fyou know of any old post to help me dissasemble the powerhead to get at [pistons...
On a limited budget!!
Tks
 

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: 1994 150 Magnuim 2,5L EFI-damage on one piston.

You replace one piston, sleeve if needed, and new rings on the rest.

You really need to determine what caused the problem, pictures would be helpful.

Make SURE all ring lands are CLEAN, long idle times can crud up ringlands causing a ring to stick when the hammer is put down on a cool motor.
 

mxzer29

Cadet
Joined
Jul 15, 2008
Messages
27
Re: 1994 150 Magnuim 2,5L EFI-damage on one piston.

You replace one piston, sleeve if needed, and new rings on the rest.

You really need to determine what caused the problem, pictures would be helpful.

Make SURE all ring lands are CLEAN, long idle times can crud up ringlands causing a ring to stick when the hammer is put down on a cool motor.

Thanks..I will get some pics tonight... can I do this with the motor still on boat....can I just get at the crank insted of taking the powerhead off??
hopefully some pics may help you help me determin whaat happened>
 

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: 1994 150 Magnuim 2,5L EFI-damage on one piston.

Sorry, powerhead has to come off the mid-section, upper and lower caps have to come off and intake half of the case comes off.

Some have managed to just pull the carbs and reed valve, reach in and pull rod cap, but it is tough dealing with rod bearings. Not impossible, but it really adds to the difficulty level.

I would want to see the ringlands on the rest of the cyls to be SURE this isn't about to happen to another cyl.
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,589
Re: 1994 150 Magnuim 2,5L EFI-damage on one piston.

This is more likey a injector or ECU problem, have them sent off and cleaned/tested before running again...
 
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