Is there a problem with using the suprem 7 FM recivers with small gas engines and elec.ing. I cant seem to git rid of throttal glitches on a 120/4star with a evo 26 gasser.

An excellent usually bullet proof receiver. To verify problem is with Ch3 of RX, try swapping aileron & throttle servo leads, and see if same problem transfers to ailerons and throttle remains AOK. This whilst range checking at various throttle settings on the ground. it could be the servo, leads or intermittant fuel supply - little gassers are notorious for fluctuating fuel feed problems as they age or have been sitting unused for a period.
Refer also "Radio Systems, Accessories, Alterations and FAQ" sub section
"Receiver - FAQ, guides and aids to best reception.." on my web page.
If above does not assist, send RX in for a full service check.

Regards
Alan T.
Alan's Hobby, Model & RC FAQ Web Links

I have tryed 3 diffrent suprem7RXes (2new one from another plane) also tryed two diffrent servos, rerouted ant and servo wires. All the ing and everything but the bat. is mounted in front of of firewall, bat. is under fuel tank. All radio stuff is away from ing as fare as I can get it. There is nyrod for throttal with nylon cleves at servo. I tryed a Airtronics RX and it works fine but I want to Kknow why the Hitec RX wont work

There shouldent be a problem using the receiver (an FM receiver) with the gasser if things are set up properly. As what was noted above, gassers do typically create a harsh RF enviroment and special precautions need to be taken when setting up a plane with one. It sounds like you do have things set up properly with isolating the throttle pushrod with something non metal and spacing the receiver away from the ignition source. Heave duty twisted wires/extensions should also be used.

I got to fly the plane today with the Aitronics RX and although it range tested fine it was real twitchey in the air. So now it does look like I have a Transmiter problem. Any way its off to the Tech gods now.

Was the range check done with the engine running when it passed the ground check?

Yes it was running and tested at all diffrent RPMs. Most of the trouble with the Hitec recievers came at close range with ant up or down. Same check with the Airtronics RX was OK on the ground but in the air the plane just flat flew funny. I keep on eather over controling or under controling it and I could not get it to trim out right. I have used this Tx in a Sig something extra for some time and seldom flew it because it flew the same way and I allways thought it was the plane. I am now using Airtronics TXes in both planes and they are both fine. I sent the TX in to have it checked so Ill see what what happens or what they find out

The only thing I did not change and I should of tryed was the module. The one in the TX now is a 57 and I have a 48 but never thought to try changing them to see if the problem went away.