If you buy a 440 kit and have it installed in your cylinder, you'll have almost as much money into it as an Athena kit by the time you have the old sleeve bored out and the new one stuck in. When you buy an Athena kit, you still have your stock cylinder and piston to sell and offset part of the cost.

I put Stage 1 hotcams in our Z and was pleased with the power increase, but I have no experience with Webcams. With the Athena kit and better cams you will still be very reliable as long as you don't get real wild cam profiles.

Been around some Athena big bore Z400's that would take my YFZ, but they did spend quite a bit--carb, head porting, etc.

 

i know a couple of people that use a yfz carb.you'll need a throttle (yam.) to.

there is 4 of them on e-bay right now

 

does this yfz carb just slip in to place ?or are there other mods to do to make it work?

 

How is throttle response/torque COMPARED to stock carb? Or should I go with a slightly larger 450r carb? I'm about to do a 460cc big bore......