I have the itch to get a Brown Junior or other antique gasser. I am not so interested in using a modelectric coil etc. Could I use a RCEXL for the little sparkplug? I am thinking I would eliminate the points and make a new hub with a magnet. Could I use the points with the signal and ground leads? I would use a modern opto kill switch, no throttle. It would be used to fly a vintage free flight design, maybe a giant Buccaneer, with RC assist.

Yup, I've done that many times. Use just the whit and black wires from the hall sensor plug. Make sure of your connections. The white wire goes to the moveable part of the points, and the black gets hooked up to the engine crankcase for ground. Either a CH or RCExl ignition without the auto advance will work fine. Notice I said WITHOUT Autoadvance.

John

If you are going to use a hall sensor and put a magnet in the hub, you can use Autoadvance feature, although without a throttle, there is no reason to use it. I have some units without Autoadvance. I could send you a diagram on a setup I used.


John

80" Powerhouse, 65 4c, FIXED timing. Putt Putt idle. 30 min of big lazy flying on 6oz of FAI fuel w 20% gas to keep a little heat in the engine during prolonged low speed operation

Why without autoadvance? If the timing is set right for high speed would't it just lessen any kickback?

If you feel the need for it, go right ahead and use the Autoadvance feature. It does make starting a lot easier, less kickback for sure.

John

Why not fixed timing? This is not a 300 cid V-8, its a .65 cid 1 cylinder. The actual idle between fixed and variable timing was about 100 rpm with the timing set at 30 deg BDTC. A small adjustment on the carb and the idle was the same. In flight the cruse rpm was in the 14-1500 range. Kick back was less than when it was operated on glow.
In reality I have found that variable timing is of only a small use when the engine is less than 30cc (1.8 cid). On bigger engines the idle improvements make it worth while. But starting kick back is a null point. After all what is the difference between hand starting a G-62 on a magneto or if its on fixed timing. You just need to have your sh*t together when hand starting a big fixed timing engine, if your scared or timid it WILL bite you.

I do not think autoadvance it is needed or even desirable. The RCEXL ignitions come with it. Is it being suggested that I open up the ignition to modify it? If it works as is why not use it as designed? The modelelectric coil and associated parts would cost more than the RCEXL. I see simple ignitions here:

http://www.modelflight.com/larrydavidson.html

The voltage is only up to 3.6 So I must use a second battery pack, adding unneeded weight. That also means I can't use the opto bec to switch the ignition on and off. It just seems much simpler and less chance of RFI to use the RCEXL.

I know all about kickback. My 65cc Stihl 4-stroke got me real good a while back. At first I thought I might have broken a finger. I made the attached glove. I glued heavy belt leather to the back of a work glove with shoe goo. It have saved me pain on several occasions since I made it.