Hi Steve,
I ended up getting my son to print me some nylon washers 2mm thick save me heaps of filing the washers out to fit over the shaft. One washer is fine as long as it is about 2mm. The washer goes under the3 leg lifter to compensate for the 3 lumps you cut off. The nut on the outside of the cap is a problem, I have tried several ways but the last batch I made up I used resin and once it had set I drilled and tapped it. This idea seems to be working the best. You still need the throttle cable so you can rev it up when you need to, the second screw is tapped through the original kill switch hole, once you have the cable fitted you put the screw in so the throttle can't be pulled back too far to prevent the cable popping out of the lifter. The kill switch did this job originally but they were just too hit and miss to work consistently