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Mercury outboard 125hp won't stay running

R

Reanski21

New member
Hi Guys,
I've got into a pro lem after I past a river full off weeds and algae and the motor got overheated and stopped running. I let it cool down and it attempts to start and sometimes starts but shakes for a minute and dies. When I put it to throttle it stays running otherwise it does dyes or don't start. I also tried to drive it when it starts but dyes as well. Any thoughts greatly appreciated.
 
The water flow is perfectly fine during the minute running, and I sprayed carburater cleaner into all 4 cylinder and still run first time for a minute and then give up until I wait the next try which about 10 minutes
 
Having overheated an engine one time at WOT and locked it up due to piston to cylinder friction, you might wind up having to remove the exhaust manifold plate and having a look at the piston skirts. If you decide to do that and find lines running the length of the skirt, and with the piston moved out of the way, the cylinder wall, those are friction marks from the piston and cylinder scoring each other. Result could/would be friction between the rings and the cylinder walls rather than a slick interface making for high resistance competing with the fuel air charge your engine receives, especially noticeable at idle and low rpms. My guess.
 
No one here was there to evaluate what happened when motor stopped.----We do not know how hot it got.----There are stickers available to indicate how hot a motor got.-------But by doing a compression test and posting your numbers , you can get help.
 
racerone said:
No one here was there to evaluate what happened when motor stopped.----We do not know how hot it got.----There are stickers available to indicate how hot a motor got.-------But by doing a compression test and posting your numbers , you can get help.
Click to expand...

Good point. Too much friction would/could keep the cranking rpms too low to develop adequate compression and that's an answer without removing anything but spark plugs.
 
Ok, I did a compression test yesterday and I got 120 each and the motor was running for about 40 minutes until I stepped it my self. Today I did another compression test and it was about 100 and the it won't last 2 minutes running. Not sure what is this. Also when its in throttle it run no stop but when actual driving it it dies faster.
 
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