In my experience any time you replace the rings you should do a valve job as well. I've seen a couple cases that the valve job wasn't done and soon after the increased compression on an old engine soon caused valve problems.
They are a vary simple and basic engine. To just do the rings could be trouble as past experience is once you tighten up one end you find the next weakest link.
You might find the valve guides worn as well as the valve seats. While the piston is out you should check the rod as well for fit onthe crank.
We have found you can normally only rebuild about twice before the cam may make noise do to wear so also check the clearences there.
Hey Jet, i traded for it a short time ago. I like the old cubs. I do have a 1988 model 1811 that i use every week to mow 3 acres. I got rid of the ford 8N and bought the 1811. I want to make the 149 a good running usable tractor and let my son have it when he gets older.................He is 14 now and helps me with the yard an figure if we rebuild it together it would be a good experience for him................Don
Sounds like a great idea, I did that with an old Toyota truck I had. The engine didn't need rebuilding but I had a spare so my son and I rebuilt it and installed it in the truck. It got him interested in all things mechanical.
Hey toadhill, i didnt have anyone to do that stuff with me when i was a kid, but i think its important to teach them that kind of stuff. I started buying him some of his own tools when he was about 11. We mess around with our dirt bikes and lawn mowers, trying to teach him some stuff.............i have 2 decks for the 149 and all i need is to rebuild the engine and a few driveline parts and she should be good to go....