Need weedwacker electronic ignition circuit!

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tsnyman
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Need weedwacker electronic ignition circuit!

Post by tsnyman » Tue Sep 02, 2003 8:55 am

I converted a RYOBI
weedwacker 31cc Engine to rc airplane engine.<p> Because the flywheel and coil is quite front heavy I would like to replace it with a variable electronic ignition system with advance and retard to make for easier to handstart.
Remember there is no rope to pull!<p>Can Someone please help with a cicuit!
PS
(I am not an electronic buff so
please SIMPLE TERMS)

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haklesup
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Re: Need weedwacker electronic ignition circuit!

Post by haklesup » Tue Sep 02, 2003 12:42 pm

I searched on "2 stroke engine controller" and "two-stroke Ignition" and found this tutorial that might help
http://www.imm.dtu.dk/courses/02224/E2.pdf

Bernius1
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Re: Need weedwacker electronic ignition circuit!

Post by Bernius1 » Wed Sep 03, 2003 4:43 am

* Does the engine NEED the flywheel? Maybe the prop isn't heavy enuff.
* The flywheel magnet activates the transistor drive coil, so it acts as a tachometer sense, which you'd have to replace.
* The magneto coil will need to be replaced, maybe with a larger or heavier auto-type coil.
The only other firing source I can think of is a Xenon strobe circuit. Use a larger capacitor & coil, & 10,000 volts is possible. But it'll draw from the battery, while the magneto's energy comes from the flywheel. Are stun guns legal in your state?
Can't we end all posts with a comical quip?

cjc1103
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Re: Need weedwacker electronic ignition circuit!

Post by cjc1103 » Wed Sep 24, 2003 10:18 am

There are several solutions to this problem that are commercially available. C&H Electronics sells a electronic ignition conversion for R/C aircraft use. Search the internet for model airplane engine information, repost this question on a R/C airplane news group.
Chris

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dacflyer
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Re: Need weedwacker electronic ignition circuit!

Post by dacflyer » Thu Sep 25, 2003 9:53 am

YOU DO NEED THE FLYWHEEL..2 reasons... harmonic balance and also the flywheel houses the magnets to generate electricity for the magneeto coil..inside this coil houses the electronic ignition..so ita a self contained unit.. cannot modifi this..<p>r/c buff here and also small engine wizz.<p>why not use a hand held electric started like the r/c guys use on med. to large aircraft?
i have one here i use... look at
www.towerhobbies.com they have electric starters and gear reduction starters also...cheaper than the engine mod your looking for...
good luck !

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