I am about to setup my first fuel plane after flying electric for a couple of years. With electric, the throttle is controled thru the ESC, and channel 3 on the receiver. With fuel, channel 3 controls the throttle servo. Does this eliminate my using a 4 channel receiver? I am using the normal air, elev, throttle, and rudder contrrols. Is a duplex connector used to combine one of the channels with the battery input?
Or is the normal fuel setup to use a least a 5 channel receiver?

usually a "normal" whatever that is ...is 7 channels.....but don't worry....just use a y harness on the throttle channel with the battery on one side and the servo on the other...or any other channel

I use
Channel one for ailerons if the plane has them other wise it is the rudder
Channel two is elevator
Channel three is throttle
Channel four is rudder unless there are no ailerons

If there are two aileron servos I use a "Y" harness on them

Make sure that the receiver isn't a park flyer receiver. They will not have the range need for a glow fuel plane. We routinely get them out 2000 ft or more and a lot of the mini recivers are only were good for around 600t.

Ifly with 7 to 9 channel receivers mostly,using 5 or6 chanels. I could just aeasilly flywith four though using aY harness on theaileron and a match box on thesplit elevator planes.

Don

Campgens is correct I didn't think of a park flyer receiver as I have never owned one