Can I re-use this Piston?
 

Taking a little break from the PoJo project to build up some build funds. I am going to fix up the Yerf and throw it up for sale. I figure that now is a good time because people may be looking for Christmas presents. Just my way of thinking, but when I sell something, I don't want to sell them junk. When I first got my HH, it smoked like a banshee, so I knew that it would need a new piston at least. So I picked up a piston and gasket set to do the top end, but then the bug bit and I ended up going a little further (see sig). So I had the parts to freshen up the stock top end and figured on throwing it on the Yerf.

I was a little shocked to se the damage when I pulled the head and cylinder. When I pulled the valves out of the head, I discovered that it was just a paper weight. The valves and seat were shot. So I pulled out the old HH head and pulled it apart. It looked pretty good, so I lapped the valves, put new seals on and it was ready to go. Next I pulled the cylinder and found this (see pic below). It reminds me of a 2 stroke that someone ran way to lean. Also to get the wrist pin out I has to heat up the piston and use a small air hammer to drive out the pin. Of course the cylinder was shot as well, so I grabbed the old HH cylinder, honed it and ring gap and piston clearance are still in spec. Luckily the rod and rod bearings still feel good, so who ever gets it should have a nice little buggy when I am done. You just never know what kind of abuse our toys have subjected to by the POs. That's why I always do a minimum of a top end rebuild, when ever I buy something. Enjoy.

That looks overheated, either from lack of oil changes, or just heat. I would toss that one in the scrap pile.

I would toss that in the. Garbage. Don't re-use that on ur buggy. Pistons ain't much $. :)

I do believe the title question was facetious ... when i got and tore down my SD, its slugs didn't look much better.

That depends on what you want to use it for.

Yeah, I was having a little fun with the title. The Piston will go on my "Shelf of Shame", where I keep some of the more interesting fails that I run into.

Now I know why I got the Yerf so cheap. From the amount of aluminum that had been transferred onto the cylinder, this engine should have been seized, but the top end had never been taken off. In fact when I removed the cylinder, I just bumped it with my hand and it slid up. However, the fan shroud had been taken loose and not been put back just right. So I suspect that the PO seized the motor, pulled the fan shroud and broke it loose with a wrench.

I'm not complaining though, with just a little bit of sweat equity, someone will get a nice buggy and I will be able to get my purchase price back many times over.

Just remember, never throw away your old parts, you never know when they may come in handy.

Put that piston on the buffer and buff it. It will be all right.:biggthumpup::biggthumpup: For a gear shifter knob.
I agree either lack of oil or too lean.