Very strange loss of compression while cranking???

[Okie]

My neighbor has a China made 2 cycle jack hammer that would not start after storing with ethanol gas mix for several months.

He came by with the carb, knowing I work on 2 cycles,, inquiring if it might be a bad carb. He does not know anything about 2 cycles or engines UNTIL NOW. We looked on computer and carb and tune up kit was $18 from amazon with free shipping and free returns. I told him to order the carb but check the spark plug for spark first and let me know when he gets the new carb in and we will install and adjust.
Yesterday he called and said he got the new carb installed and it ran really good for one day, but now no start next morning. I went over and found no compression and the piston not going up and down. He said it almost started for few pulls and then went to easy pull on the rope??????????????

I suspect carb was leaned out, but a rod coming unhooked while pulling the rope?????????
He said he did not think the carb needed adjusted because it was running so great, but seemed like it was getting hot.

China Plastic rod or crankshaft melted????

He said the whole rig was around $300 and warranty just expired.

Strange one from China?????????????????

 

[Homer6679]

Straight gassed?

 

[chipper1]

China made

 

[Okie]

Straight gassed?

Maybe,

I suspect his new carb was operating very lean, but ?????????????

He also did know the difference in mixed gas and straight gas because I warned him if he ever needed to prime his chainsaw or the jack hammer to prime with MIXED gas.

He did not know the difference in ethanol and Non ethanol gas when at the fuel pumps, because he said he would start buying premium gas for his 2 cycles. I had to tell him where to find non ethanol gas in our neck of the woods.

He is gaining some woods and 2 cycle knowledge/experience the hard way where it's $$$'s coming out of his pocket book.

 

[Old2stroke]

It's unusual to get a broken rod or crank failure, make sure it's not just a problem with the recoil starter, remove it and turn the flywheel by hand to confirm.

 

[Okie]

It's unusual to get a broken rod or crank failure, make sure it's not just a problem with the recoil starter, remove it and turn the flywheel by hand to confirm.

I did that. I can actually push the piston down somewhat through the spark plug hole and the crank don't move when the piston is being pushed down but the crank will sometimes raise up the piston but not pull it back down. (appears rod cap is off. I did not pull the muffler to take a peek since I knew it was trashed and the muffler is not easily removed without moving some heat guards, etc. (since I already knew was whipping on a dead horse. If it were mine I would have investigated further just to see what the innards looked like. I also have a bore scope