I have an OS .46 FX engine that i bought from a gentleman at the flying club i visited last week. He said it was a spare that he had and didn't use. I cannot get the engine to run at idle or full throttle without the glow driver on. Is the glow plug toast? Also being a newbie to this engine was wondering is the idle mixture adjustment in the hole where the throttle cable is attached?

Thanxs

sorry one more thing do i have to loosen anything to adjust the idle mixture or should that screw just turn without having to loosen anything else?

thanks

How is the compression? A couple years ago, OS-46FX engines were plagued with the liner peeling. On mine, the compression was low and although it would run, the power was low and it wouldn't stay running for long.

DaveB

After you check the compression, as Dave suggested, replace the plug. An OS #8 should work well. Do not do anything with the low speed needle until you've got the high speed needle set. You should be able to find an engine manual at the OS Engine site.

It is likely that the plug needs replacing. Yes, the idle screw is the one that you can see the slot of inside the throttle linkage. Nothing needs to be loosened to allow turning this screw, but wait until you get it running before touching that adjustment. In all likelihood, once the plug is changed to a good one, the idle adjustment will be good while the high speed may need to be adjusted for peak speed depending on the differences in the atmospheric conditions from when it was last run and now.

Another thing... At least on my FX and LA 46's... If you do need adjustment
be it hi or low settings... The range is very small once your close... So a
click or two can be plenty... I make 1/16-1/8 movements on mine when I
need to, which is not very often... But as said above, change the plug and
try it before adjusting.... And as chuck said D/L the manual that way you
can see where all the adjusting/stop screws are at, plus suggested settings.

http://www.osengines.com/manuals/50s...1fx-manual.pdf

Re: "I cannot get the engine to run at idle or full throttle without the glow driver on."< sounds like the high speed setting is very rich. This means that the glow plug is probably getting wet with fuel which will douse out the glow when you remove the power. Slowly turn the needle valve in until it is complety closed. Then open 2 1/2 turns. Now the engine should start and keep running. Slowly go to full throtle and sloly turn the needle closed by turning clockwise unitl you get max rpms. Then open counter clockwise by 3 clicks. Lift the plane and point it up at the sky. After about 10 seconds the rpms should still stay steady or slightly increase in speed. If the engine starts to slow down or quit, open the needle valve 2 more clicks and try again. When you have a setting that the engine will run steady the high speed valve is set. Now adjust the throttle trim for around 3000 rpm at idle. If the low speed valve is set ok, you should be ready to go![8D]

thanks for all the info. i will replace the plug and see how that goes

flyboy76