do you have to have a bigger carb? if so what do you recommend? how big is to big? will a port job make that big of a diff...?

 

stock carb is 36mm I think. I went to a 41mm fcr because I had it ported and motor work done
if you dont port. all you should have to do is rejet. if you want a bigger carb I
wouldnt go any bigger than a 39mm. and porting does help as long as its done correctly
a 41mm might be to big for the 434 kit but then again it all depends on jetting and how
much power you want. when you have yours done are you going to run a 12/1 or a 13.5/1 piston?
12/1= pump gas
13.5/1= race fuel
I have to run race fuel in mine, I get it from my boss we buy it in 55gal drums at $4.50gal
1 week at the dunes between my quad and his sandrail and his friends rail we'll go through 100 gals

 

i think my carb is a 37mm, i'd prob. want it ported , but i'm not sure who i trust to do it and is it worth the money.
i'm really not try to go all out. i'm not sure what comp.. i want. the fact is 12:3 to 1 , im not sure if i want to run race gas or not
what do you run? c12? or a high octane like 110. i use to mix u4 50/50. didn't like it, made it rev. to fast and har to jet.

 

Your '05 carb is a 37, they are 1mm larger than the 04 & earlier. Your cams are a hair bigger too.

DAB in Utah is the guy for porting on Z400 heads, he does a bunch of them and has the right equipment and knows his stuff. Very good to talk to on the phone. Around 500 bucks and he ports, flowbenched, sets up your cams, the whole shebang.

Best bet on big bore is to go ahead and buy a cylinder. If you spend 600 for the Athena, you have a new cylinder and can ebay your old one for a couple hundred. That way you're in it for around the same as sleeving, and you have the higher cooling capacity of the new cylinder.

With all that done you then actually will need more carb. They say the Honda 450R carb is a good one that's not expensive like going to an FCR. You can pick them up used.