Hi everyone,

About six years ago i bought a profile plane, looks like a Sig Fazer. Had an TTR .46 pro on it and only till last year i tried to run it. Did run, but does not idle well. Took it to fly and somebody ruin the cyl head plug thread. bought a new cyl head and it still does the same good high rpm but no idle.

I tried to set it, but seems like i took it off setting. Does anyone know what the factory timing settings are. I am really interested. or how I could try and set it.

I would like to see this engine idle, otherwise I'll have to buy a new one.

Best regards,

pt6pilot.

Aruba

I never bother with factory settings. Use an OS #8 plug, Fox R/C, or Enya #4; all work well. An APC 11-4 or 11-5 prop, and 15% nitro fuel. Now when you start it up set it for peak and then about 3 clicks rich of peak, point plane up to be sure it doesn't go lean, if it does then open needle valve with plane pointed up till it peaks then one click rich of that. Now go to idle, set plane down and pinch the fuel line. It should speed up slightly and quit. If it doesn't speed up it was too lean, so open the idle mixture on the right, inside the barrel, 1/8 th of a turn and try again, do this till it it speeds up slightly when you pinch the fuel line. If it speeds up a lot and runs for more than a second or two then it was too rich. In that case close the idle mixture 1/8 th of a turn. After this you should be able to trim out the idle throttle for 2,200 to 2,500 RPM with good transition.

BTW next time you have a stripped out glow plug, have it helicoiled, it usually costs less than a new head.

Hi Sport_Pilot,

Thanks for the info.

I guess there was something i did not know yet. Correct me if I understood wrong. The needle valve sets the high rpm only and the "screw" on the throttle link sets the low "idle" rpm?? if this is so. i'll post later if i had any progress or luck.

thank you.

Have a good flying day.

pt6pilot.

When you say "screw" on the throttle link, its not clear which screw you are referring to. If you look at the throttle arm from the side of the engine, inside the arm you will see a small screw. This is the Low Speed Needle. Turning the needle clockwise will lean the low speed mixture, and turning counter-clockwise will richen the low speed mixture. Make very small adjustments (1/8 turn or less) and always recheck the high speed needle after adjusting the low speed. With an 11x5 prop, the Pro 46 should be turning around 13,000 rpm at full throttle, and should idle very reliably around 2750 rpm.

As for glow plugs, I prefer the OS A3 over the OS #8 for my Pro 46.
Brad

You set the idle RPM with your transmitter throttle trim. I think you might be looking at the barrel retainer screw, that screw holds throttle barrel in place, the idle mixture screw is inside the barrel on the right, in the middle of the throttle control arm. It does not set speed, but the mixture. Sounds like you need a manual, you can download one from here.

http://www.acehobby.com/ace/manual.htm

Thanks Brad and Sport_Pilot,

I will read the manual and if I am not wrong i already have a OS A3 plug on the engine. The screw i was referring to is the one in the middle of the barrel.

Thanks for the help.

pt6pilot

Way too hot! For 15% the Fox which is slightly colder actually gives the highest RPM and best fuel economy, with 10% the OS #8 and Enya #4 is best. Extra hot plugs such as the A3, Enya #3, make it easier to tune, but you will have a richer mixture during at peak RPM and thus less RPM and poor fuel economy.