Quick Guide to H2 Performance Gain
Outlined below are steps to significantly improve H2 performance with minimal effort:
-Obtain 2mm copper lift plate for cylinder base
-Buy VM38 carbs
-Use Q2 Needle Jet
-Use 35 pilots
-Use 6DH4 needles (same as VM 34)
-Use 220-300 mains, dependent of pipes and tune
-Buy FKS 004 spigots. Mikuni brand, easily found on Nichecycles or Ebay
-Make the holes a bit oval for proper carb lift (to clear the cases). Not necessary if a 2mm lift plate is used.
-Use the ex port shape as described here. ROUND ALL PORTS AFTER PORTWORK. The edge cannot be sharp, more like touching a plastic comb so to speak.
-For a real torquey, not so Wild set-up, do not raise more than the 2mm copper plate provides.
-For a bit more lively tune, compensate the cyl lift by raising inlet duration by cutting and the make the profiled piston skirt. I would say max 3mm (1,5mm in total).
-Make sure you get as smooth tapered exhaust duct as possible......there is A LOT of material (castings inside duct) to be removed after the window itself has been widened.
-Remove head gasket and use a high temp silicone sealing, for compression after the lift. The best way is squished-band heads and decked cylinders.