ORIGINAL: ZAGNUT
and the $120 you quote for the CH includes the synchro-spark auto 'tard module that you won't be getting with the TIM circuit.
if you're up to building the ignition yourself then ask CH for their tested circuit board and coil and do the rest on your own. should only be around $60. much better than saving $12 and doing the TIM-6.
dave
Hmmm...a quote from the CH web site
http://www.ch-ignitions.com/
WEED TRIMMER CONVERSIONS
Complete ignition conversion for some weed trimmer engines. Includes
ignition, prop hub nut, washer, timing clamp and pulse switch. Does not
include switch harness, battery pack, spark plug, engine mount, muffler
or the Syncro spark module.
Add $40.00 to any system for built in Syncro Spark timing control.
I will inquire of them how much a build it myself kit with the Syncro Spark would be. I'm very comfortable with electronics since that is my trade.
I'll reconsider the issue of longevity and review the forums about the TIMs systems. But from what I read here, everyone is saying the TIM6 is an issue. What about the TIM4 or TIM3?
JEH claims that TIM6s have run for years on the 6 volt system.
He says that the system will run on 4.8 - 7 V. Are our fourum reporters running at 4.8 or 6 or 7.2 V with their NiCads? The difference will have probably have an effect on the coil. Since the Coil, according to JEH is rated at 3 to 6 volts, I have to wonder if the current capability of the TIM6 isn't too high at 6 volts.
Thanks everyone, I'll sure put this info to good use.
BTW, I don't plan to just put it in a plane and go fly. I'll run her for a good many hours on the post in the yard first.
Tom