Cylinder is .004 Out of Round......too much?

edzeb

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Feb 2, 2017
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I am rebuilding a HM100 159022L (B) 3320D.
The bore measures .004 out of round. Too much? Need to go .010 over?
The bore otherwise looks fine. No scores, no marks.
Thoughts from those of you who have rebuilt these before?
Also, the valve guides are sloppy. I do see that you can purchase oversized valves. Has anyone here ever reamed the guides on one of these engines?
Finally, any suggestions on any specific parts suppliers you like more than others?

Thanks!
Ed.
 

Rivets

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Yes, this engine can be rebored and rebuilt, but is it worth the cost. Here are some questions you need to have answered before proceeding.

1. What and how are you getting your reading. Cylinders should be measured at three positions, (top, middle and bottom) plus you should take two readings, 90 degrees apart, at each location.

2. Valve guides can be reamed oversized, but make sure valves with oversized valve stems are available yet.

3. Have you measured the crankpin and connecting rod journals and bearings, making sure they don't need replacement.

4. Have you priced out the cost of your repairs, is it cost effective?

5. This manual might help you out.

I've rebuilt these engines many times in the past, when prices were down, and didn't need reboring or resizing. Used to do my own reboring if needed if customer wanted it done. You need to ask yourself, is this engine worth the cost of a complete rebuilt. Also, ask yourself, if I leave something's out and the repair doesn't last, was it cost effective? You have a tough decision to make.


http://www.mymowerparts.com/pdf/Tec...P-4-CYCLE-L-HEAD-FLAT-HEAD-ENGINES-692509.pdf
 

edzeb

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Feb 2, 2017
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Rivets,

Thank you for manual and info. I have no problem boring the cylinder and reaming to larger valve stem. The lower end looks fine, but I will mic and plastiguage them tonight. Is there one parts vendor here that everyone likes more than any other?

Thank you again,

Ed.
 
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