Outdoor Power Equipment and Small Engines - Subaru EX-30 rod replacement

I was able to tear down the engine today and the large end of the rod is .002-.0025 out of spec on the large side...hopefully this is where the knock is coming from. Max dia is .049, currently is .0515.

With everything out except the crank, I was able to mic the crank and it's within spec....thank goodness.

The pin is just at the limit with the OD, I figure I will replace the rod, piston, pin, rings, and clips. I will have the bore checked and was curious if it's within spec, can I just hone the cylinder and replace the above mentioned?

There was literally no ridge at the top of the cylinder, piston came right out easily. Not sure how many hours are on the engine but whatever caused the rod to wear is anybody's guess.

So will a hone job do the trick or are these motors real finicky?

Here's a few pics, thought it could be detonation also since there is a bit of carbon built up on the piston.


http://i11.photobucket.com/albums/a180/gtofan1/DSC_73080001.jpg

http://i11.photobucket.com/albums/a180/gtofan1/DSC_73070001.jpg

http://i11.photobucket.com/albums/a180/gtofan1/DSC_73090001.jpg

http://i11.photobucket.com/albums/a180/gtofan1/DSC_73050001.jpg

Looks like normal carbon buildup on the piston. Get the parts you listed, hone the cylinder with an oiled hone and obtain a proper cross-hatch pattern on the cylinder walls with it. Hone it until the glaze is pretty much gone, and wash the cylinder and engine out to remove particles of the hone rocks and metal dust. Reassemble and you should be fine. These are tough engines and if you have no ridge at all, the cylinder should be in spec. Expect it to run like a new one when done if all parts are in spec.