Seized engine

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  #1  
Old 07-08-03, 05:07 AM
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Seized engine - brand new power washer

I have to open with: "I didn't do it".

A family member, who will remain unnamed, borrowed a power washer from a friend. It actually belongs to the friend's dad, who had never even taken it out of the box. The friend loaned it to this family member - without his dad knowing about it. This family member ASSumed that there was oil in it despite it being very obvious that the thing had never been used. There wasn't. It ran for about 30 seconds before seizing.

So, the family member bought a new $600 power washer for the friend's dad and now has the broken one. We took it apart and found that the cylinder is not scored and the head isn't warped. It appears as if the connecting rod seized to the crank. The "bearings" (cast into the cap and rod) are toast. The crank appears to be okay - the surface doesn't have any scratches other than what appears to be the machining (can't catch a fingernail in it).

The local power mower repair place wants $40 for a rod assembly (though it's $11 on line) and says the crank should be replaced or "it will throw a rod". It's a B&S 6.75 OHV engine.

Has anyone done something like this before and repaired it? Should I replace the crankshaft, too? What else could be suspect?

TIA,
Jim
 
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  #2  
Old 07-08-03, 05:58 AM
Joe_F
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Lol. Bring it back and get another one . (That's mean though).
 
  #3  
Old 07-08-03, 06:45 AM
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Originally posted by Joe_F
Lol. Bring it back and get another one . (That's mean though).
I would, but I suspect they've seen this before. My brother (the previously unnamed family member) already got a new one for the guy anyway. It's a nice machine - it would be nice to have in the family if we can get it running again.

Jim
 
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Old 07-08-03, 06:13 PM
mikejmerritt
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I think I would follow normal rebuild rules. Check the crank journal for wear and out of round, put a rod in it and cross your fingers. I doubt the rod has damaged the crank in any way. You could get a pressure washer out of the deal for 11.00 and a gasket set. I think a set of crank seals would be a good idea because they probably got very hot. Good luck with this project.....Mike
 
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Old 07-08-03, 09:42 PM
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I agree with Mike...Check the crank over...it is probably still good, but....you mentioned machining scratches....there should be NO visible scratches on the crank...it should be satiny smooth. If you see scratches, they are probably not actually scratches. It is most likely aluminum from the rod, smeared onto the crank. You can use fine sandpaper to remove them if they are very thin and small, or use an acid to dissolve the aluminum from the iron. If aluminum IS smeared onto the crank, it will probably sieze or throw a rod when built if it is not cleaned off first.
 
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Old 07-09-03, 04:03 AM
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One thing that works good to clean a crankshaft is 240 grit emery cloth. You can tear it into a strip about 3/8" or 1/2" wide and about 1 foot long and wrap it around the crankshaft so that you can pull each end of the emery cloth and it will sand all the way around the crank, then after a few light passes, wrap the emery cloth around the other way to it is angled in the other direction, then make a few more light passes. Doing this will not only clean the crank but it will put in those "machined scratches" which are called cross-hatch marks. This gives the oil a path to follow while the engine is running. Cross-hatching a crank is something that is pretty much done on any large engine overhaul, so it will not damage the crank in any way. Also, make sure to wipe the crank clean before installing it. As mike said, you will probably need some new seals for the crank. When seals get hot, they get soft, and when they get soft, they don't seal oil as good as they used to.
 
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Old 07-21-03, 09:08 AM
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Thanks for all the replies - I didn't get an e-mail notification so I'm a bit late in getting back.

After getting a second opinion on it, we decided to replace the crankshaft, too. I think it was all under $50 (crank, rod/piston assembly, and the gasket kit). We fired it up yesterday (after putting OIL in it). Works great.

Thanks again,
Jim
 
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Old 07-21-03, 10:10 PM
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Good Job!

Glad you got it fixed!
 
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