any more power?

[foxr]

i got a 400ex with a 440 big bore kit, jetted, k&N, white brothers full exhaust, and possably have a cam in it as well.. is there anything else i can do to get some more power out of this engine? seems to have alot of power but i want more!

[firefighterjosh]

What do you mean by possibly? Did you buy this quad without knowing what is in it?

[foxr]

yup, it was a fresh rebuild when i got it and the dealer told me what he was told from the previous owner

[firefighterjosh]

:huh Sounds scary. Well depending on what is done to the engine. Sounds like it is a stock engine sleeved and bored to 440. Valves, springs, cam, stuff like that will help with power. If you want some easy power go get a 450.

[foxr]

bit scary yeah but ive riden it around atleast 50 hours this year with nothing done to it but basic maint, it has been super reliable considering when i ride alone i got the throttle pinned.

[firefighterjosh]

Sounds like you got a good deal. I have heard some scary things about 440s. My friend had one. I feel sorry for whoever bought it. It looked OK but the engine work was horrible. (He thought he was a master mechanic):eek2: The only thing I would watch out for is you compression higher compression on a 400 it will start blowing head gaskets.

[ride_red666]

you can rebuild it and put in a +4mm stroker crank bringing it up to a 460 or even get the fst 502 stroker kit but thats getting unrelaible. you could port and polish the head, bigger carb, or even a turbo.....

[firefighterjosh]

TURBO IT!!!

[foxr]

is there a kit to turbo it? i obviously need a lower comp to do this i think its ethier 11:1 or 12:1

[brapbrap13]

crf450 motor

[foxr]

motor swaps require cutting and welding on the Frame?

[firefighterjosh]

Yes there is a Turbo kit for them. I seen it in Dirt wheels a cople years ago. They make one for a Raptor too.

[ITSTOCK]

Out of curiosity, why not just buy a 450?

You will have right about the same power you have RIGHT NOW with more reliability, than you still get to do exhaust/jetting/carb/cam mod...and than possibly stroker kit or just up the compression. It doesn't make sense (monetarily AND reliability speaking) to push the 400 much farther.

[firefighterjosh]

Thats what I said earlier in the thread

[QuadJunkies]

with the proper set up a 440 can be as reliable as anything else.


I would get yourself a 450R carb ,you will be amazed how much more poop it adds.:D INSTNAT throddle response!Go ask anyone who has done this and they will tell you.

I run a 12:1 and have NEVER blown a gasket.
Do your homework and you will love your 440 ;)

Tina

[newrider4002001]

change the sprockets that will give ya a little more power

[krt400ex]

u will notice a diff if u put on a bettr exhaust. sparks, hmf, or yosh are all way better than white bros