The engine has never been run because of the wobble, I'm afraid it would tear the airframe apart. You can turn it over by hand and see the prop bolt move up and down. I know that it is off-centered.

i wouldn't buy anything from HK..........maybe battries like zippy or turnigy..........thats it..........RON

I have purchased several items from them and this is the 1st time I had anything wrong where I needed customer service. They can't even spell customer service let alone provide it. What a shame that a company for a lousy 2 or 3 dollar part would treat a customer like this. Like I said, I opened a dispute with PayPal and I hope they make them squirm. If one person who was going to buy this engine after reading this post decides not to, then I will have won.

Ok goirish, I’m just trying to help.
If this engine was dropped at some point this also could have bent the crank.
The cranks bend very easy.
You might try “Zenoah” for a replacement part, many of these engine are just cheap knock offs of a more popular brand. I have no idea if any parts will interchange though.
BUT
I do have several 26cc engines, one of which is a Zenoah the other ones are of different brand names and most if not all of the parts are all interchangeable with each other.
I’m just trying to help get you in the air so you can enjoy this wonderful hobby.
You might also try tower hobbies, see if they offer an engine of the same size. If so there is a very good chance that it is the same engine.

One of the reasons I would question that the hole is drilled off center is because of how this part is machined, the part is chucked in a cnc machine and the part is turned. The drill bit does not turn, if the piece is not centered with the drill bit the hole would be board out to be wrong size. The part is machined and drilled without ever being removed from the machine.
It is just about impossible for the hole not to be in the center.

The people you are talking to at hk also know how is part is made, they probable think that you are crazy. That may be why you can’t get anywhere with them.

HK advertises that all of these engines have been run for 7 minutes. If that were true they would have seen that the prop wobbles. Don't tell me something if it isn't true. I don't know what the problem is, all I know is the prop has a wobble to it. I'm talking by turning it over by hand. Lords know what would happen if I started the engine and got it up to 6,000 rpms. but you know what, I am going to start the engine and see what happens. I will take it out of the plane because it is worth more than the engine.

I have been drilling and tapping hole's like this for more years than I want to remember and you can most certainly get it off center if done wrong. The hole may not be the culprit if the face is off is will cause the same effect. If you can't get any results give me a PM, i'm sure that we can come up with a quick easy fix and get you back on track.

That is what I have been thinking. maybe where the crank extension bolts to the crank shaft that may be where it is off if the hole is drilled in the center that could cause the same problem. Never really thought about that. My simple mind can only think in one dimension (hole drilled off center). Not sure how I would check that. Thanks for the heads up.