You need to get the stock mugen flywheel, and only use one thin shim between the nut and inside bearing, and no collet shims between the tapered collet and the engine bearing...
I would also gring a 2.5mm headed screw just a little bit to give it more clearance. The 2mm screws strip out too easily...and Use one of these to keep the bearing inside if one fails itwont go through the tank...
http://www.amainhobbies.com/product_...Head-Washers-4
the tank is too close to the screw head on the mugen, I have very light rub marks on my tank, never had any issues though...Mostly because I shim the bearings really perfect, with just a slight tick.....I can go three to four races on a set o clutch bearings. Some guys change them twice in one day....