Tweet
I re-powered my Big Max with a 420cc engine so I needed to switch to a 4 cycle clutch setup. I'm running the comet 40 series because price was way lower than some other options. The driven pulley was available in 7/8 bore but comes with an internal key . I had to use an arbor press and broach but was able to make a keyway without removing the internal key and the setup works great so far. Now what to do with the rotax 503 hmmm