I use the WYL's also on my Briggs and Stratton 4 stroke conversion, we have done four now. Just remove the spring, cut all but two windings off and reinstall, works very well, very little resistance and still keeps the tension. We had to drill out the barrel to get to the mixture adjustment (high end only) but that was no big deal. ours are idleing at 1450 dependably and peaking at 6200 with an 18-6. This doesnt sound all that great but it sure flies our WWI planes great and the sound is super.