spark plug cap keeps falling off minarelli a/c engine

This morning on the way to work, disaster struck (once again)...

Within the last 4 weeks I have already replaced my spark plug cap, as it kept falling off the end of the spark plug all the time. Now the new plug cap has started to do the same. It's only been on the ped for approx 3-4 weeks & has never been removed since being fitted.

My question is... is there an alternative spark plug cap that can be used that will allow the screw part of the spark plug to be retained, rather than the current LB05F cap which uses the screw threads of the spark plug?

 

Think I could have found an alternative.

http://www.sparkplugs.co.uk/graphics/images/caps/LB05F.gif

What do you think about substituting the LB05F cap with an LB05E cap?

 

i used to put abit of silicon on the outer part of the cap just before the rubber cap on the end then it grips the plug but best thing to do which wont fall off is get a soft rubber/sillicon spark plug cap and put a zip tie around it once its on the plug then tighten it enough that it holds

 

Some spark plug caps clip onto a little nut or what ever its called on top of the spark plug so if that has fallen off could be causing your spark plug cap to fall off

 

The LB05F cap cover is designed to be used without the little nut, but the LB05E is designed to be used with the little nut.