Grizzly Engine & Transmission 686 BBK with shims November 30, 2015 My 660 is bored to 686 and I’m running 25" big horns. The only way my 140 lbs can wheelie this thing is standing on the rack. I miss wheelies now that I have a storage box. Suggestions on shim size? 1,1.5? Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related