OS 61 SF Assembly Problem
11-09-2022, 07:23 AM
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OS 61 SF Assembly Problem
I was given an OS .61 SF engine. I guess it was originally a heli engine because it has a rectangular head. But it was previously used on an airplane and I want to use it on my Great Planes Seawind 60. I took it apart and replaced the bearings with new generic bearings. I reassembled it, put a prop on it and realized it was tight and would no longer turn over. I figured out the problem. But I'm not sure what's causing the problem. When tightening the prop, the prop hub it being compressed against the front of the crank case. Initially I thought maybe I bought the wrong bearing. But I think now it's the right bearing. I'm wondering if there is supposed to be a washer between the prop hub and the bearing that I'm missing. I can't find an exploded view of it being that it's is so old. The other question I have has to do with the crankshaft key. It's the usual half moon shape, but one end is flat. I'm thinking that flat end goes towards the front. I think that's the way it was. But I'm not sure. Any input would be appreciated. Thanks
11-09-2022, 07:32 AM
#2
Just a guess, but it may be that your bearings aren't quite seated. Heat on the case, an old prop, and a big wrench to tighten the prop really tight may fix it all up.....
All precautions apply - don't melt/burn things, wear heavy gloves....
All precautions apply - don't melt/burn things, wear heavy gloves....
11-09-2022, 08:11 AM
#3
Originally Posted by tedsander
Just a guess, but it may be that your bearings aren't quite seated. Heat on the case, an old prop, and a big wrench to tighten the prop really tight may fix it all up.....
All precautions apply - don't melt/burn things, wear heavy gloves....
All precautions apply - don't melt/burn things, wear heavy gloves....
11-09-2022, 08:20 AM
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I figured out my problems. My friend got the engine from someone else and never actually ran it himself. I pulled the hub on another OS 61 I have and realized that there is a washer between the hub and the bearing. I now know the first owner had hub off and lost the washer because the key was backwards when I got the engine. It was protruding slightly out of the hub. By putting it flat side forward it sits flush. I think the hub is thicker on my other .61 because it's key doesn't have a flat end. I just have to find a washer the right size now.
