lower the cylinder and ports?

[2T5]

Many thanks for the detailed information, teazer. Appreciated!

Would this have a marked effect on fuel and air requirements?

[teazer]

Typically, on something like a GT750, carbs and pipes are changed as well, but it really depends on how well the motor worked before the changes. Raising ports will favor top end power and with more time-area, at lower revs that might reduce intake velocity so adding fuel may be required.  At the top end, if the pipes match the new ports, the extra revs could mean higher intake air velocity requiring less fuel.  But could also need more fuel is required if it was close to being lean before or if the extra heat from running harder requires a richer mixture to compensate.

No hard and fast easy answer.  Always start rich and on the safe side and work down to the best jetting.

[2T5]

More great info. Thanks, teazer!