Hi there gents, can anyone help, I have a brand new homelite 25cc which I have converted and installed on an 81" span model it has a 16x8 prop fitted but just doesn't seem to be giving enough power, I haven't been able to check the RPM, do I need to put a pipe on the breather, are there any things I can check or change to get more power, I have a home made silencer fited which seems to work well (is there a set size I should work to ?) any info would be greatly appreciated. Thanks, Joe