Yep. I've clamped CH ground leads to plug thread faces for a long time. Very effective. I found I had to use a properly-narrow hose clamp; if too wide, it would interfere with the head, and not tighten properly. Yes, you *may* ask how I found that out......

ORIGINAL: dirtybird
ORIGINAL: closetguy
THANKS
To all,to make it a little clearer i mounted the ground strap to clyinder base bolt,but from what has been said it won't be good enough,i will call CH electronics to get a Bosch cap,don't know how to get a hold of TKG like RCIGN1 said to,and for the time being i want to try moving the ground lead to top cooling fin,did't know it was that sensetive,i want to fly this plane for the first time (snow is gone). i was un easy about clamping the ground to plug (to easy to come off).
THANKS for all of you guy's help,this is my first CH ignition didn't know the first thing about them.this at lease gives me more things to try,i was at the end of my rope,didn't know what else to try!
ENJOY GUY'S!!
Don't try to install the Bosche cap yourself. It might require changes in the module to make it work. Send the ignition to C&H and have them do it.
Clamping the pigtail to the spark plug base may look crude, but from an RFI standpoint its the best way to do it. You want to get to the ground the shortest way possible. It won't come off if you clamp it down hard.