ORIGINAL: beepee
Crismedicatrix,
I converted my US41 some years back. Bought a CH Ignition and installed it myself. No problem. I estimate 10-12 ozs. saved with the ignition battery pack. You HAVE TO remove the spring starter as it cannot be used with electronic ignition, but as stated above, you don't need it. Easy hand starts.
I disagree with above statement. There is no noticable performance improvement at the top end. There is a smoother, more reliable idle.
You won't get much weight shift by moving the ignition battery pack back, 'cause you will start getting too close (stay at least 11" away) to radio gear. Can't move the ignition module back. It has a short spark lead and doesn't weigh anything anyway.
Have fun!
Bedford
If you didn't get any performance improvement, then you don't have full timing advance. Did you create your own hub to replace the flywheel? Where was the magnet position (degrees before top-dead center)? Is your CH iginition the "syncro-spark" type? If not, then all you did was convert from static magneto ignition to static electronic ignition. Your only benefit in that case would be the weight savings as you pointed out.
As for weight and balance, typically the iginition box is behind the engine on the firewall somewhere. Yes, it doesn't weight much, but what weight is there is probably 4 to 5 inches further back than the front of the engine where the flywheel and coil was. The battery pack can be even further back inside the front end of the fuselage for even more balance improvement. 11 inches is overkill unless you have some kind of defect or a poor performing receiver. You can definately get closer than that. However, I do agree that the futher from the radio gear, the better. Just make sure to range check thoroughly.
I could have used my spring starter just fine on my engine after the conversion. However, it wasn't needed since the engine started so easily by hand. I chose to lose the weight instead. Removing it was purely an option, not required. Maybe the CH conversion kit you bought installs on the rear end of the crank shaft. If that's the case, then yes, the spring starter will have to go.
Cris, If you go with the conversion kit that Bedford is describing, see if you can get one with the timing advance feature. The CH product is called "syncro-spark". If you're going to do the conversion, you might as well get the power benefit as well as the weight savings. There would be virtually no difference in weight between the CH static unit and the CH syncro-spark unit. There will be a cost difference though.