Good engine I’ve Ben running os65ax on my engine stand more I run it better it runs once low end is dialed in it’s sweet running and prop sounds good to when hit throttle,I’m putting mine on a sig 4 star 64 ,Happy flying.
Congrats Tim, those are generally brilliant engines! I’m too cheap to buy one, I generally go looking for old but still new in the box engines on the secondary market. Lots of people still dumping glow engines to switch to electric here in USA. The one thing to be aware of, the factory rear bearing is a bit undersized and low quality for the load. If you hear the bearings “grumbling”, don’t hesitate to pull the engine and replace the rear bearing with a premium quality Swiss or Japanese bearing. If the rear bearing fails, it likely would destroy the engine, and in flight, could well cause a crash that destroys the plane as well.
Thanks, are there any other issues/ things to do differently now you’ve had it for a while? Are you pleased with its flight performance? Thanks a lot for the info as I hate trying to change things once I’ve built a plane, I like right first time🤞👍
Hi, a friend gave me a brand new OS 91 FX a few years ago & I have been thinking about buying the same ultra stick as yours. My question is that the 91 seems to have the same crankcase dimensions as there 61 butt is 2-3 oz (65-85g) heavier because of the exhaust being bigger. Will I be able to get the C of G right WITHOUT needing to put weight in the tail somewhere with the slightly heavier motor??? Thanks
