Originally posted by PatternFlyer
Flyinrazrback is corrent.
How is your rear bearing so far? How many flights do you have on the engine?
OS 140RX has two versions.
One is standard pumped version. The other is an EFI that does not have pump and electronically controlled fuel injection.
Many people flying pattern with 2-stroke engines use OS 140RX.
There are other 2-stroke engines such as Webra 145 Aero, Webra Bully, 3M Mintor etc.
All the above engines work very well in pattern applications.
For the OS140RX, people discussed bearing life a lot.
Many of them didn't last very long. Not really sure why.
I heard most of them complaining about the bearing life had rear bearing failure within 300 flights.
I am also considering one of the afore mentioned engine.
Real problem with the rear bearing is it's too small. Much too small, IMO, for the amount of power the motor puts out. It's the same rear bearing used in the OS 1.08. In that motor, it's about the right size, but in the 1.40rx, it's way too little bearing to support that huge crank.....
Mine lasted about 3 or 4 gallons before it went rough and started putting out black residue in the exhaust.
When finally I took the motor apart, my jaw simply dropped when I pulled the crankshaft. Here was this enourmous, stout crankshaft riding in this eensy little tiny main bearing.
No wonder they go bad so fast.
Motor sure runs good, though. But it really needs a redesign with a much stronger main bearing.....
LS