Fuel flow question
#1
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From: Beasley, TX
I've been running an os 46 (nexstar) for about 6months and today I had some dead sticks on throttle up doing touch n go's. I noticed that dropping the throttle from high rpm to low there is fuel flowing back toward the pressure fitting on the muffler. Is this normal? I have not really paid attention to the flow other than thru the high speed needle up to this point. TIA for any advice.
#2

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From: Warialda NSW, AUSTRALIA
G'day Mate,
Sounds like your low speed mixture has gone a bit rich, this is normal, as the motor runs in, & needs to be leaned a bit, so you get good throttle responce, you may need help, don't be afraid to ask.
Sounds like your low speed mixture has gone a bit rich, this is normal, as the motor runs in, & needs to be leaned a bit, so you get good throttle responce, you may need help, don't be afraid to ask.
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From: Beasley, TX
Thanks for the reply. The plane was bought used so the engine is broken in (if that is what you mean by run in?)
Also this happened after the engine was already warmed up. Do you think it is a too rich mixture? Thanks again.
A little more background: Engine tuned after warm up (1/2 throttle for about 30 or 45 secs), high speed adjusted from 4 to 2 cycle, lean until smoke almost disappears and richen by 2 to 3 clicks. Fuel is new.
Also this happened after the engine was already warmed up. Do you think it is a too rich mixture? Thanks again.

A little more background: Engine tuned after warm up (1/2 throttle for about 30 or 45 secs), high speed adjusted from 4 to 2 cycle, lean until smoke almost disappears and richen by 2 to 3 clicks. Fuel is new.
#4

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From: Warialda NSW, AUSTRALIA
G'day Mate,
Yeah idle mixture sounds rich, run it up to full power, then back to low idle, & pinch off the fuel line to the carby, with your fingers or a pointy pliers, if it picks up lots of revs, before it starts to die, then the idle mixture is too rich, lean it 1/8 of a turn or a small amount & test again.
It should gain only a small amount of revs, as you pinch, when it does it is set, & you will get a good progression from idle to full power.
Yeah idle mixture sounds rich, run it up to full power, then back to low idle, & pinch off the fuel line to the carby, with your fingers or a pointy pliers, if it picks up lots of revs, before it starts to die, then the idle mixture is too rich, lean it 1/8 of a turn or a small amount & test again.
It should gain only a small amount of revs, as you pinch, when it does it is set, & you will get a good progression from idle to full power.



