ORIGINAL: ALANXP
hi
this is my quote from an os forum
'MY os 140 quits(hunts and quits) at 1/4 throttle in flight it seems that the engine has fuel starvation at this piont,because when I prime the engine it take a couple of flicks to prime it .I did test the engine on ground (pointing the model vertical at full throttle and back to idle then full throttle . idle reliability-left the engine running at idle for one min and to full throttle (didn’t miss a beat)).My set up apc 17x10N home brew fuel semsynt 18%oil 15% nitro glow type F os carbon pipe. I have also read that after 30 flights the engine needs to be cleaned. Can I inject methanol in to the pump by a hand pump with out removing the engine and pipe but leaving the pipe attached to the main needle (also removed) and disconnect the 2nd pipe ?'
Well I did clean the pump and found a lot of gum,althoug I think it did help becasue the flight duration was longer but still the engine is hunting even when my funtana 140 is flying stright and level at 1/4 thottelThe engine quits at TDC.Should i install a hopper tank ?I did flly with the glow on.Should i adjust the slow end needle ?
Alan
Alan, are you sure that you don't have a bad throttle servo (hunting)?
You should not leave your onboard ignition on when the engine is running peaked out. It is hard on the glow plug and it doesn't do the engine any favors.
Why are you accumulating goo in the carb at thirty flights? I'd investigate that issue (dirty fuel) before I changed anything on the engine. The OS 1.40RX is intended to be used at a competition engine. I can't imagine any pattern flyer putting up with an engine that needed to be disassembled every thirty flights. Many pros put more flights than that on their model in a week. That would consume a lot of their time. I suspect there were certain qualifications to that 30 flight period that we have missed.
Good luck. You have a great engine.
Ed Cregger