I have an 03 z400. My plan is to get an Athena 434 big bore kit, hot cams, and upgrade my clutch. I just have a few questions before i buy and install these mods. 1.) Can I get away with just jetting my stock carb with these mods or will i have to buy a bigger carb. If so what kind and size of carb should i go with??? 2.) Will the bike still be reliable with this mods or am I going to have to worry about having problems with it??? 3.) Is there anything else that im going to have to upgrade with these mods. Reliability is my main concern. Any and all advice will be helpful. Thanks.

P.S. Will I be able to beat a piped Banshee with these mods?????

 

Heres my advice: Do a wiseco 440 kit and save your money. Skip the hot cams and go with webs cams. Hot cams do not make as much power as web in my experience. Also there is quite a few other things you will need to do to take advantage of those mods. If you use the stock carb, you will be cheating yourself out of extra hp you could have. My next move on mine will be a bigger carb and then a four stroke tech 460cc big bore kit. hope this helps

 

So dont go with the Athena 434 and go with the Wiseco 440? Im going to get a bigger carb eventually but im on a budget. I already have jets to rejet it. I figure i wasnt going to all the horsepower out of it by going the "cheap route". I just want to make sure its going to run for now.

 

one thing you need to think about between the 2 kits, the wiseco 440 requires the jug to be bored and have the sleeve put in, and the athena is a bolt on system so the wiseco might cost a little less but you have to pay somebody to do the machine work for the wiseco sleeve . the 03 came with a 36mm carb on it. you can rejet it but if you want the power you need to go to a fcr 39mm
and as for the banshee question you wont beat one with those mods. IMO

 

You should easily be able to find someone to do the work for you. Yes you can use your stock carb for now. I also heard that the athena kit you may have to do some grinding for it to work. Me personally, I don't want to pay 600+ dollars for a bolt on kit that you have to grind to make fit. Kinda takes the bolt on part out. I'm either gonna do the 453cc or 460cc kit and have a stock cylinder sleeved. I'll buy an extra cylinder off ebay to make down time less.

 

when I had my 440 kit the guy who did it took the jug and had it bored and then nikasealed, it was a true 440 and not sleeved, it costs a little more but I think its worth the time and money to have it done. gives you something else to think about

 

look on e-bay for a yfz 450 carb--39mm... got mine for $150

 

how much difference did the yfz carb make?

 

i could tell it ran better, yfz carb is so easy to rejet. you dont have to take the bowl off ,just a little cap.

 

YFZ 450 carb? Not a bad price. I should be able to afford that. I guess the Athena 434 is out of the question if im gong to have to grind it down. Oh yeah... I was searching for big bore kits and i ran across a 450 kit for the z400 from lukesracing.com. Has anyone ever heard anything about this kit.. is it good or bad???