I have been looking at getting into club 40 racing. The local clubs that are racing (novice class) require plain bearing 40 class engines with a stock muffler and stock mute (baffle) if supplied from factory. I have a few good OS 40 FP's and an old Tower 40 which I think is just an FP clone. I have had these for several years and do not have a mute in any. I can't rember if they came from the factory with one or not. I don't want to violate the rules and can't find any information or part numbers for the mute. The mute is not listed in the parts list that came with the engines that I can find. Does anyone have information on the mute? Part number, size, existance? Thanks in advance for any help.