ORIGINAL: Flyin Beagle
I have one of these
http://www.osengines.com/history/osm...2-max-40rc.jpg
new in a box and have installed it on my old trainer. When I went to start it to begin the breakin, I found that the airbleed screw is missing. I have looked on the internet to see If I could find one, but have had no luck.
Will any scew work in this as long as it is threaded correctly, or does the tip have to be specially shaped?? I am new to air bleeds.
Is there supposed to be a spring over the screw to hold it in adjustment??
Anything else I should know about this motor??
Break-in can be accomplished without the airbleed screw in place. Break-in is accomplished at high throttle with the needle valve set very rich. Fuel should contained 20 to 25% castor oil for lubricant and 5 to 10% nitromethane. Forget throttling the engine during break-in. Just run it with the carb opened all the way opened. Castor oil fuel is important for this and other OS engines of the same era. a 10x6 or 10x5 propeller is perfect.
Depending upon the type of fuel being burned, we sometimes used to completely remove the low speed airbleed adjustment needle with this and other similar sized OS engines. They ran perfectly that way.
This type of engine requires the use of an idle bar equipped glow plug. Yes, there are a few non idle bar plugs that might work, but finding one that will could be expensive since you may have to go through quite a few before you "get lucky" and find the proper plug. No, it won't hurt anything if you run the wrong plug. It just won't throttle as well as it would with the proper plug. I used to use Fox R/C Long glow plugs (idle bar equipped) and received good performance from my OS Max .40 - H engines.
Good luck. I always did with my engines of this type.
Ed Cregger