:lol:

Got the YS 1.20 apart, sure enough the main (rear) bearing took a dump on itself. Lucky for me the hunch was right and I already have the replacement parts (front and rear bearings along with all engine gaskets). Should be flying again by the weekend if all goes well. :thumbup:

It's kind of a crappy picture, but just notice the part at the top where one of the balls is supposed to be but decided to move. The formerly retaining metal pieces are scattered about the crankcase a bit.

yep looks to be back running in no time

Ouch!!! Glad you found it before it ripped everything else up.....

same thing happened to my O.S. 46fx except it happened mid flight.....can we say new piston and sleeve

Mike,
Any luck with the bearing replacement?

I hope so! Engine is completely reassembled and put back on the Funtana. I'm planning to fire it up after work tonight. If all goes well I'll be flying tomorrow!

Hmm...well, I can't get it to fire. And now that I've got everything well oiled and turned over several times I'm starting to realize this thing really doesn't have much compression. I'm afraid it may need to be pulled back apart and have a new sleeve and ring installed as well. I'm going to bring it out tomorrow anyway for a few second opinions though.

Hmmm, it should have at least as much compression as before. Are you sure that the valves are opening and closing right?

Mike,
When that bearing went, some metal might have scored up piston/ring/sleeve enough to loose too much compression.

And/or if you disassembled the entire engine, might not have got the cam back in correct position relateing to timeing marks or whatever they use to align it so that valves will be working correct in relation to piston stroke position.

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Ooops, Jon beat me by few minutes. Got to get me a speed keyboard.
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I know the cam is (or at least should be) in the proper position. There is a punch mark on the side of the cam gear and with the piston at TDC the punch mark was at 12:00 when installed, as instructed by Dave Shadel, the YS rep on RCU. So I can only assume the valves are working properly. I'll take the cowl off of it tonight and maybe some more knowledgable folks can take a look at it with me tomorrow.

It's alive!! Big thanks to John Lafleur, Roger Hagler, and Jon Koppisch for helping out today, after a few pairs of knowledgable eyes got on it things got turned around right quick to where they needed to be (literally). Running great now. :thumbup:

What did you find out after I left?

Besides the rocker being off the pushrod which you saw, the regulator/pump assembly was 180º off. I knew it would bolt up either way, and I thought I had it right.....I didn't. The Doc found that and I put a new diaphragm in it just to be sure and it fired right up as if it never had problems.

That's what I was wondering. I had to leave before you took it off... I knew that the pump wasn't developing near the pressure that it should. Glad it's working great again!!!!

Jon