i always ride my father inlaws 400ex but it is very slow, and i was wondering how much extra power/speed i can get with a 440 big bore kit

 

40 HP is the norm for a 440. I estimate that I am about 43-45 horsepower with my EX. My goal is to be around 52 by the summer.

 

will it be a night and day differance or just very mild differance also what is the stock hp on a 400ex

 

like 28 or so

so 45 and 28? one HELLUVA difference [img]i/expressions/face-icon-small-happy.gif[/img]

 

and buying that kit i should need no other parts just the sleeve piston cam, and i have to resleeve the jug is this all i have to do to get the 45 hp or around there

 

I went with a cam at the same time being that you have it apart. Also, put the oversized studs in at the same time. If you don't you will blow head gaskets. You will like the end results. I went with a larger front sproket because of the extra power, 16T. and if you realy want to wake it up get a different carb.

 

Gone,

This is what you need to make a successfull 440 with around 45 HP...


1 ) 440 Big Bore Kit (Piston, Rings Sleeve)
2 ) Edelbrock 38MM "Doug Eichner" Carburetor
3 ) Web camshaft
4 ) Web Valve Springs
5 ) Web Hardweld Rocker Arms
6 ) Web Shortened Valve Guides
7 ) LTE Dual Exhaust
8 ) Web 1mm oversize intake and exhaust valves
9 ) Heat Porting
10 ) Labor to Install

This is what I have on my EX. You can get similar parts from different manufacturers. Those parts and labor should be about $3000 depending on the shop and where you buy your parts.