Old OS .40FX will not fire
 

I just took my old trainer out of the garage today. I'm planning on building a new one. The radio and receiver/servos work fine. But the OS .40FX will not start.

In order to get the motor to turn over with my electric starter, i took the head off, and poured a little bit of fuel into the cylinder and carb to lube it. Then i cranked it over with the starter. Now i have it back in one piece, but i still can't get it to start.

I downloaded the user manual, and set the screw to 1 -3/4 and 1/4 throttle, and changed the glow plug. Still will not fire, keep in mind it has been sitting about 8 years.

Also, the fuel i am using is 15% and it's just as old as the motor (this may be the problem). It was kept dark and cool during the time it was stored.

Any thoughts?
Thanks guys (and gals)

RE: Old OS .40FX will not fire
 

yep get rid of that fuel....pour any excess out from the glow plug hole.....make sure your glow stick has a charge..
Good Luck

RE: Old OS .40FX will not fire
 

Bob,

Its the fuel, its gone bad over time. If the engine has compression, the glow plug is good, and it has good fuel the engine should run.

RE: Old OS .40FX will not fire
 

Thanks guys, i'll stop by the local hobby shop and grab some new. It's kind of a shame to toss 3/4 of a gallon of it away though.

I'll let you know how it turns out :D

RE: Old OS .40FX will not fire
 

Don't feel bad about tossing it out - it's useless or worse.

RE: Old OS .40FX will not fire
 

Use the old stuff for cleaning engine parts.

RE: Old OS .40FX will not fire
 

Indeed do not throw that fuel out. A good long soak in old fuel can be even more effective than the much advised crook pot and antifreeze. Especialy so for an engine stiff or frozen with castor deposits and varnish.

John

RE: Old OS .40FX will not fire
 

I had one of those motors and had to wind the needle out at least 3 turns, now I know what the manual says but there is a real possibility that the fuel is not getting through because the needle is in to far. Keep winding it out and if that doesn't work check the low speed idle screw, if that has become gummed up there may be a blockage there as well. If the glo plug is ok and fuel lines are ok that would be my next step.

Good luck with it

RE: Old OS .40FX will not fire
 

What is the standard break in time for an engine such as this? The fuel that i have is the only fuel i have ever gotten for it. is 1/4 of a gallon enough? Also, if after this long time of sitting, is there anything i should do to extend the life of the motor?

If the 1/4 gallon is not enough, what would be the recomended procedure to finish off the break in?

*Side note for those interested* I built this trainer when i was younger, and never flew it. Now i'm going back through, took everything apart, the fuselage(sp?) is broken. And i am considering building another trainer. I'm just looking to make sure the motor and radio/receiver/servo systems are up and running before i start.

RE: Old OS .40FX will not fire
 

Go ahead and build another. That OS engine will run, even if you have to get some help at the field to start it the first time. Your radio is most likely still good too, but I'd replace the transmitter and receiver batteries.

RE: Old OS .40FX will not fire
 

And a quarter gallon is probably close enough, but run I'd run it on the ritch side the first new tank through, just to be sure. You may have built up a little corrosion in places (I'll bet my hat your bearings are brown) and it'll be good for it to run for a minute and clean itself out.

RE: Old OS .40FX will not fire
 

Take the HSN valve completely out. Put your finger over the muffler outlet and turn it over with the electric starter. It should spit fuel out where you took the needle valve out. IF not, then it is gummed up in that area. Side note make sure you don't have the glow plug connected to make it hot when you put the electric starter on. You are not trying to start it, just cleaning out the needle valve assembly.
Good luck