As Jody and bill says,probably the plug cap make sure the cap is going all the way down. When any of the RCEXL caps are on properly the wire snap ring must be all the way past the hex of the spark plug.They do not go easy and come off even harder. We seem to get more RFI complaints on 2.4 then we got on 72.I think the reason for this is back then a lot of fliers were using just the rubber boot and a resistor spark plug this was nearly always OK. Now many of the fliers are using the RCEXL cap or somthing about like it.We find nearly all RFI compliants now are caused by cap not being on all the way or wrong cap on wrong spark plug. You could not believe some of the things we see of fliers trying to use the wrong combination of spark plug and cap.Like 5/8 cap on 3/4 plug 3/4 cap on 5/8 plug.5/8 hex on CM6-10MM plug just trim the cap down a little.Will not work they have to be right.The small hose clamp is a good Idea.We always used a hose on the Bosch plug covers,kinda ugly but works. Use a fuel line clamp only 5/16 wide not 1/2 inch.We have instruction on our web site on how to get the RCEXL cap off with out using pry bars,vice grips or dinamite. O yes they do.
BCCHI