fried impeller housing merc I/O any ideas why?

[steve n carol]

Did the search's on this topic. <br />Read what I could find. The situation is this;<br />I am re-sealing the 1/R outdrive behind a mercruiser 225s, impeller and it's components were fried. The impeller housing was blackened and warped, lower driveshaft seal was only medium rare, going back down, the 2 impeller housing seals, located at the bottom of the pump were well done. Remarkably the impeller itself was just a bit warped!?<br />This unit is new to me. I have never put power to it, yet. It appears that it was run w/o the muffs or any H20. Upon removal there was gear lube mixed w/a little water.<br />Q)any experiences with the exhaust entering this system? possibly through the outdrive cases, blocked passages?? If so where would this might happen??..sl

 

[rodbolt]

Re: fried impeller housing merc I/O any ideas why?

about the only way to melt a housing is someone started it while demonstrating "how good she run" on the trailer with no water to cool the pump. many people are of the mistaken impression that its ok to start it on the trailer if its only for a minute. my guess is the water came in after the seals got toasted.<br /> good luck and keep posting

 

[steve n carol]

Re: fried impeller housing merc I/O any ideas why?

Thank you Mr. bolt. I am putting this back together, assuming that it was possibly damaged in this manner....sl

 

[Blk-n-Blu]

Re: fried impeller housing merc I/O any ideas why?

steve and carol, you may want to look at the water pocket cover and be sure its not warped and allowing exhaust gas into the lower unit. Look here:<br /> http://www.marinemechanic.com/site/page150.html <br />Good Luck.

 

[steve n carol]

Re: fried impeller housing merc I/O any ideas why?

I checked this as well, achris posted a method to pressurize the h20 cavity, spray wd-40 around the perimeter and check for leaks. I did this 3 different times. (I am a belt and suspenders type, ha!), no leaks detected. Thought for sure it would have been shot. <br />Supposing that this would have been warped, does this only disrupt the water flow, or does this allow some exhaust gasses to enter the cooling system? Besides changing the bellows, I have never worked w/the exhaust comming through the transom/gimble. (The 'Y' connection and the other related parts), don't think I'd enjoy it..sl<br />tell me what you think.

 

[Blk-n-Blu]

Re: fried impeller housing merc I/O any ideas why?

well then, since you covered that base I'll say rodbolt covered the other What caused it question.