Snake River Rat

my question is; will an fm radio system work with a weedeater motor ? I have one installed in an alluminum Jet boat with an Echo motor. With the motor idling, and power is turned on the throttle servo goes nuts! I had the same problem with an AM system. Please give me some advice

krayzc-RCU

My Feedback: (31)

the motor to receiver do not know that it was in a weed eater 1st. def check that spark plug i bet it just a a-2 vise an RA-2 the R = resistor

jschuring

another thing to check..... metal to matal contacts that are not tight will definitely cause the symptom you describe....AM or FM..... be sure that your linkages use nylon clevises on metal arms or vice versa... this can be a major source of servo jitters if metal clevises are used with metal servo arms.... any thing that allows metal parts to work against each other due to vibration.....and no.... the metal internal parts of a running engine have not caused this as far as i know.....also make sure the spark plug boot and lead is shielded

Good luck...
Jim

nigel1

vauxall in the UK used to fit supressors to the spark plugs of their engines by using a special adapter where the spark plug lead could be plugged onto it.

I wonder if the plug firing is causing the interference? Vibration applied to the reciever can also cause servo jitter in FM systems here in the UK if you don't wrap the reciever up tight in some padding it will vibrate and this may be your answer.

A.T.

Agree with earlier post, most similar problems resolved by eliminating any possibility of two pieces of metal rubbing together, double check all bolts are tight and cannot vibrate, especially mufflers and fittings. Use metal ball joint with nylon cup, or swivel joint as used on Heli linkages, on the throttle lever and "R" type spark plugs.
Refer to Guide to receivers - and solving apparent RX & "Interference" problems as well as other information on my web page under "Radio Systems, Accessories, Alterations and FAQ" sub section "Receiver - FAQ, guides and aids to best reception.." and "Petrol engines, carburettors and ignition systems"
Regards
Alan T.
Alan's Hobby, Model & RC FAQ Web Links

supertiger2004

You might consider changing your radio from 72mhz to the new 2.4ghz. I have a gas powered airplane that i could never fully enjoy flying because of spark plug interferance at low RPMs every time i came in for landing the plane would get hit hard with a glitch but now with my new XPS system the glitching gone and i didnt have to waist anymore time tryiing to find out what is causing the interferance, i just set it in the wind and fly.

Rodney

I fly many weed eater motors with the PPM radio system, both AM and FM with no problems. Just make sure you use a resistor plug and do not have any metal to metal contacts that can vibrate or rub together. Any metal to metal connections must be very tight and not move relative to each other. I try to keep at least 6 inch spacing between any of the ignition parts and the radio system and use a non conductive throttle pushrod with no metal to metal clevisis or ball joints. Keep the kill switch in front of the firewall and, if using electronic ignition, keep the battery for the electonic ignition away from the radio electonics as well.