G'day

ive had previous bad delemahs with building big bore yzf's

but this time id like to give a crack at a efi rmz 250

was thinking about 270cc

i will do all the main things pipe tuner etc etc
i want to have the head flowed to suit etc

but ive noticed hot cams make a crap load of cams these days
and not sure wich i would go about in my selection

i like bottom and top end, so bascially some where in the middle with the big bore

also how do u propose other things would hold up like bottom ends
clutches etc, im looking to make at least 40hp but really more would be better

and gearing
how much longer do you lads go for with the gearing and wacking a big bore

obviously ill need it dyno tuned

You need to get the gears undercut as well or you may well have 40hp going no where

<sup>Pro Circuirt Cam Shafts
Pro Circuit Valves and heavy springs
EBT Ported head
Vortex Adjustable Ignition
Hinson Clutch basket
Pro Circuit heavy clutch springs
Yoshimura RS-4 Slip-on exhaust

Braking oversized front brake rotor
Braided front brake line
CV4 Cool Fuel tank heat shroud
ASV Levers
Pro Taper Ball Bearing Throttle tube

this machine made 42hp as a 250cc
im hopeing with the addition of the 269cc big bore i can crack 44 ???</sup>

You probably wont gain more than 1hp peak,  it will show much more as torque upto the lower top end of the power where you would expect 2hp more