Would like to know if anyone has had engine failure with this engine before, I have about a 10 tanks of fuel in mine and I had a hard time getting it to start, it would only run at have throttle.
When at have throttle all it did was idle. I removed the plug and found that it had very low compression. i havent even moved the low or hover needle from the start up settings yet, i have turned in the high needle about 3 to 5 clicks. when i removed the engine and the exhaust there are scratches in the piston and ring.
I dont understand why this would happen. I sent the engien in to ys and waiting for reply from them.

Never had any problems with mine until I dented the piston trying to get the crank nut off. Now I am just going to get a new YS80, since it is only about 125.00 more than fixing the YS61 that I have right now. I ran many many gallons through it with no trouble. It was hard to start the first flight of the day, but after that it ticked right over. And having to switch back to the OS61 I can verify that the YS61 make much more power.

I left the fan on mime because I couldnt get the collar to release and didnt want to mess up the crank shaft. I dont think they are going to help me but have to wait and see.

Im gald to hear they were so helpful. I hope they do the same for me. Thanks for the reply ja1010.

What kind of price is the piston and cly. and ring?

I called them yesterday and told them about it. Im not dure the guys name I talked to but he didnt seem to interested in covering it for me. I have tried to put a liner and piston in a k&b 91 boat motor i hd and it was a waisted $125. I sent them my motor this mornin and they should get it on monday. I will wait and see. I have had really good service thru OS for many years i hope ys stands up the same way. I dont see how this could be my fault
For the motor was still running almost on the startup setting.

It has about 8 to 10 flights on it. so it should be covered.