engine break in ? for newbie
 

hello all i just got my hobbico superstar it came with the o.s .40 la anyone have any tips for the break in ?

thanks in advance

RE: engine break in ? for newbie
 

This is what I do...everyone will have an opinion on this!

Just run a tank through it on the ground with it 4-stroking....cool...run a second tank through it intermittently from 4-stroke to 2-stroke...ending 2 stroke..cool. Fly the 3rd tank 1/4 rich as long as it idles and accelerates reproducibly.

RE: engine break in ? for newbie
 

well man i am a total newb to planes so what do you mean when you say intermeintely 2 strokin and 4 strokin how do i do that

thanks for the help

RE: engine break in ? for newbie
 

According to the OS manual, the engine needs very little break in. The manual will describe it better (http://www.osengines.com/manuals/40-46-65la-manual.pdf), but here is what it basically says.
I started the engine after screwing the mixture setting in until it stops, and then backing it out two full turns. They say to slowly work the engine up to full throttle (which will produce a four stroke sound) and then slowly screw the mixture setting back in. The engine will increase in RPM and make more of a two stroke sound. Keep screwing in until it reaches a max point, if you keep going the engine starts to die out again. This is the optimal setting when the engine is completely broken in. But for the first tank break in, unscrew until the engine sounds more like a four stroke (there should be quite a bit of un-burnt fuel coming out of the exhast). The book says to keep it at full throttle for the entire tank, but I cycled mine through all RPM's after talking with several people at the field.
After that first tank, they say you are ready to fly, just screw the setting back in a little making sure it is still running pretty rich. For the next six flights or so, gradually lean the engine out until you reach that optimum setting.
One suggestion, buy glow plugs with an idle bar. This will help prevent the engine from stalling at low RPM's when the engine is so rich (the raw fuel will foul the glow plug without the idle bar).