HELP!!!!

I've finally successfully installed my 32 cc McCulloch saw engine on my 1.20 size stick, (took like 3 weeks), and can't get airplane to pass "range check". With the engine at idle, antenna collapsed, all servo's go crazy at about 6 feet, and about 12 feet with antenna extended on transmitter. I have a resistor plug installed from a G-26 (champion), plug wire shielded and grounded to motor, the closest component (servo's) are 11 inches aft of firewall, no help. I went as far as applying "aluminum tape" to the entire inside of the fuselage, all servo leads, receiver, and battery pack, all to no avail. I removed all the tape, and am ready for the next solution (if any). The engine runs great, and there's no "metal to metal" linkages anywhere. Servo's are rock steady with engine not running. I'm running a new hi-tec FM receiver pack, with a JR 642 transmitter. Some say PCM will eliminate problem, others say it will make it worse. Itching to fly the airplane, but don't want to crash!!! Any help from anywhere would be greatly appreciated, I have too much time in this project to give up now.......I am currently using a 1200 mah Nickel-metal receiver pack, and have tried the 600 mah Nicd, no help either...Will it be feasible to purchase a PCM receiver, or another entire engine? The airplane is'nt really worthy of a new G-26 (test bed only), so I don't want to sink a whole lot of money into it, as this would defeat the whole purpose of the project. Both receiver and transmitter are well aft of firewall (17 inches), and closest servo is 11.5 inches....Thanks again....