how many RPMs rich?
08-21-2007, 05:52 AM
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how many RPMs rich?
Having used four strokes exclusively, Im not sure where to set my OSAX.46. On the Saito engines I usually fatten em up 300 rpms off peak. Im using a 10x6 prop. What would be the top end and safe running RPMs of this engine.
thanks,
Bill
thanks,
Bill
08-21-2007, 06:09 AM
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RE: how many RPMs rich?
I'd start with the same 300 rpm you use for your four stroke. Running rich never hurt anything.
If it transitions and operates fine at that setting there is no reason to go leaner.
If it transitions and operates fine at that setting there is no reason to go leaner.
08-21-2007, 06:41 AM
#3
RE: how many RPMs rich?
ORIGINAL: bldrums
Having used four strokes exclusively, Im not sure where to set my OSAX.46. On the Saito engines I usually fatten em up 300 rpms off peak. Im using a 10x6 prop. What would be the top end and safe running RPMs of this engine.
thanks,
Bill
Having used four strokes exclusively, Im not sure where to set my OSAX.46. On the Saito engines I usually fatten em up 300 rpms off peak. Im using a 10x6 prop. What would be the top end and safe running RPMs of this engine.
thanks,
Bill
G'day Bill,
First off, change the prop to an 11x6, 10x6 is too small for the 46AX, next thing is, run the engine up to full power, & lift the nose of the plane, if it is rich enough, it will pick up some speed, as the nose is lifted, if not richen a few clicks & try again.
Forget how many revs it is doing, or how many you slow it down after it is at peak, it MUST pick up some as the nose is lifted or it will be too lean, & probably stop as the fuel level goes down in the air, or worse still, just after take off.
08-21-2007, 09:00 AM
#4
RE: how many RPMs rich?
Ditto to most of what Allen said, but I don't think it MUST pick up RPM when held nose-up. However it MUST NOT DROP ANY RPM AT ALL
One other thing I will add to what he said is: Bring it to full power (Airplane level) and let it run for a few seconds before raising the nose. I see a lot of people hold the plane level, and raise the nose as soon as the pilot raises the throttle. Let it blow out any low-end load up that might have occurred first.
One other thing I will add to what he said is: Bring it to full power (Airplane level) and let it run for a few seconds before raising the nose. I see a lot of people hold the plane level, and raise the nose as soon as the pilot raises the throttle. Let it blow out any low-end load up that might have occurred first.
08-21-2007, 09:18 AM
#7
RE: how many RPMs rich?
Been doin' it this way for a couple years and I don't have ANY trouble.. I watch guy's come out and tinker, tinker, tinker, and take off into a dead stick all the time.. I read this in a thread on RC Groups a couple years back when I was learning how to tune engines. It has worked for me EVERY time. I've tuned my 4 TT 46's, my Mugnum 46, my os 120 ax and my ST 51 all this way with the same great results.. Just my $.02.
