rickg, some of the older ones were made from brass and worked better but there hard to find and expensive, when i replace mine with new plastic ones i drilled a very small hole on the outer rim of the plastic and safety wired em so they cant unscrew. if you allow them to remain loose you might end up with a couple of dents in your hood in the event of a carb. backfire, and you could loose them alltogether, in addition all kinds o "schmeg" can find its way into the carbs if uncovered. also if you remove the thin washer it will allow you some more thread to enter into the cap. you might find the ones you own already have damaged threads. /ubbthreads/images/graemlins/savewave.gif