My 46FX has had about a gallon of fuel ran through it, it has alwasy ran perfect from the moment I got it untill just recently. Now it will run fine on the ground but when I take off the engine will quit with in 2 or 3 mintues of being in the air, no matter what throttle setting. I have checked both needles and they seem to be adjusted right and changed plugs. etc. When the engine does quit it is abrupt, with no apparent signs of being to rich or lean. Anyone have any advice, or a simular problem?

John:

That was one of the symptoms of a peeled liner. Pop the head and look.

If it has peeled get the piston and liner set from Hobby People for the Magnum XLS 46, it's a drop in, and it's genuine ABC instead of the cruddy original ABN.

Bill.

Also did you recently change your fuel lines around or replace them. I had the identical problem you had a couple years ago. The line coming from the firewall to the carb made a bit of a right angle. Did not look pinched but it was and enough. Ground runs were fine. Engine got lean, hot and quit after a couple minutes of flight. I smply lengthend the lines. Just another thought

First off....an engine quitting in flight does not show any sign of lean etc etc.....
Do your nose up test on the ground after starting the engine and gunning it. If it begins to die...it's too lean, nose down. Richen up. NOse up again....etc until it runs full throttle without dying.
Secondly....check your carb, engine head and back plate screws. Are they tight? If so.....then check the engine liner. OS has improved on the liner...so it may not be that....but the possibility exists.
Thirdly.....check your lines for cracks outside and inside the tank.......installing a new plug does not mean it works. Check it outside with an igniter to see if it lites up.
ONe guy at our club closed his HS needle....and was trying for a half hour to start...until I walked over and started going through the above list. The carb screw vibrated loose etc etc.

Cheers.

Is your fuel tank centered with the carb.? If it is too low after a minute or two it will be harder to draw fuel-


Also, make sure your tank is padded so no fuel foaming occurs--

Keep us posted!

maybe the fuel line inside the fuel tank is too short and the engine stops sucking up any fuel after a few minutes...try and check that out.

run a full tank on the ground and see if it sucks up all your gas out of the tank....see if it quits after a few minutes.

Hope this helps...

-Paul

Recently, our local engine guru had same problem. After realizing trouble was showing up in more than one engine, found to be bad fuel. Changed and tok.
good luck, red

You noted the engine will run fine on the ground, and performed fine in the air without any noted mixture change for 2 or 3 minutes.

Sounds familiar.....

First check.. Will it run for an entire tank on the ground ?

From your initial description, I would suggest checking your fuel tank.

If the engine simply shuts-off as if it ran out of fuel:

1) Make sure the clunk line is not doubled-back or stuck 2) check that the brass pipe has not cut through the silicone pickup line 3) make sure the clunk itself is attached to the pick up line 4) and that the pick-up line itself is attached to the brass pipe.

Any one of these would cause the engine to run fine......for a while only, through only a portion of the fuel. It the pick up line is cut, off, or floating, you would expect to only run a couple of minutes until the fuel level got down to the level of the 'air leak'.

I hope this is helpful.
Bob