OS 91 DF Engine
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OS 91 DF Engine
I'm having a problem with my OS 91. I am using it with a Ramtec fan and almost everytime I start the engine, it will run backwards. Can someone tell me why this is happening. The engine has never done this until now so whats wrong.
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RE: OS 91 DF Engine
Could be a little rich on the low end. Are you hand starting or using a starter? BITD, I would flip mine by hand and occasionally it would start up backwards. If it's a little fat, it will kick back alittle harder and run backwards. Try leaning the low end in very small increments.
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RE: OS 91 DF Engine
the low end is way to rich...try leaning it out a little at a time. my bvm 91 would pop backwards if i let it idle for to long and got back on the throttle.
good luck
good luck
#5
RE: OS 91 DF Engine
Hi,
If you're not sure whether or not your low-end is rich, let it idle and pinch the fuel line. If it's too rich, it'll cycle way up before it quits. I wouldn't lean it out until I tried that.
If you're not sure whether or not your low-end is rich, let it idle and pinch the fuel line. If it's too rich, it'll cycle way up before it quits. I wouldn't lean it out until I tried that.
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RE: OS 91 DF Engine
thanks to all who replied....I too think the engine is too rich on the low end. the engine is in a Starfire II and is completely enclosed when its ready for flight. On my last attempt to start, I was having trouble removing the starting probe when the engine started and I was thinking that trying to pull the starting probe out was causing the engine to kick and run backwards. I will start leaning out the low in until the response is quick and positive after I make the test recommended by yellowaircraft
donniercjet.......I tried to reverse the starter motor wires but after two starter motors smoked, I guess thats not working....LOL
donniercjet.......I tried to reverse the starter motor wires but after two starter motors smoked, I guess thats not working....LOL
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RE: OS 91 DF Engine
You can actually set the low side needle on a .91VRDF with a feeler gauge (.060) or a number drill (#53). Open the throttle barrel all the way (full throttle). Check the gap between the spray bar and the low needle with the feeler gauge or number drill. Set it so you can just slide the gauge in and out of the gap. I have never had to re-adjust a low side needle set this way. I believe this method came from Tom Cook (Jet Model Products).
When flip starting a .91, it will frequently start in the wrong direction. Sometimes a quick blip of the throttle will correct the rotation. I have never had one start in reverse when using an electric starter
When flip starting a .91, it will frequently start in the wrong direction. Sometimes a quick blip of the throttle will correct the rotation. I have never had one start in reverse when using an electric starter
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RE: OS 91 DF Engine
grbaker, That sounds like some good advise and I'll give it a try. I am using an electric starter with a long starter wand and yet the engine will start backwards. I do the quick throttle hit but no help. I also pinch the line until the engine almost dies then let go and sometimes that will work. I will definetly try to set the low end as you recommend.