Mercury XR 150 - Piston Overheated

[Terry421]

I have a year 2000 Mercury XR 150 outboard that ran fine for two years and with no warning the motor locked up. I pulled the head and the lower left hand piston melted at the top but seems to still be connected at the crank. Any suggestions on how extensive the repairs will be and estimated costs. Any help is appreciated.

 

[hondon]

Re: Mercury XR 150 - Piston Overheated

Explain to us in a little more detail how the top of that piston looked.Was it all washed out and substantially more clean than the other cylinders?Any carbon build uneveness? Were you turning the recommended RPMs for this engine?Bottom line is you should expect to get more than two years out of your investment,UNLESS ,there is something more too the story.

 

[Terry421]

Re: Mercury XR 150 - Piston Overheated

The piston has melted around the edges and you can see the top ring. I was able to free the piston today and it is still connected to the crank. I was just starting to get on plane when the motor seized so I was maybe pushing 3500 RPMS. The piston is no longer flat it has some deformity and I can see the aluminum slag on the cylinder wall and in the ports.