H1 Slow past 110mph tops out at 120 ?!???

[Cjamster]

Having an annoying problem my zxr 400 h1 is great apart from she feels slightly less powerful than my h2
H1 very slow past 110 and the highest I got on a very looong straight was 120
And the h2 flew past 120 no problem any ideas guys thanks

Note:
Both have aftermarket end cans and stock downpipes no other power modifications

[CaNsA]

Running lean.

Tape up 1/3 of the air intake snorkel and try again.

[banner001]

or fit bigger mains to compensate at WOT