for .21 Nova engine they are come stock shimmed for 25% only their .12 engine come stock shimmed for 16%
So do u mean others .21 engine are come shimmed for 16% only?
Thanks!
Novarossi .21 on road engines come shimmed for 25%. That = .70mm of total shims. You can use 16% at this clearance with no problems, only adjusting the tune. It is also possible to remove a .1mm shim to use 16%.
Novarossi .12 engines come shimmed for 16%. That = .3mm of total shims. You can safely use up to 20% with this clearance. To use 25% you should have around .5mm of total shims.
This will get you in the ballpark.