Need Sum Info, ???????

Just bought a 99 400ex online for 1000,,seemed like a good deal,going to pick it up this weekend,it has a 440 kit custom milled cam,custom ecu,work shocks,hmf pipes,steering stabilizer,hoozier swing arm,nerfs, and it keeps up with the other 400s in its class and some of the 450s anyways he says it needs valves and new piston rings,then its good to go, people i talked to say the 400ex is a damn good bike but they dont like that it has the 440 kit on it and im going to have problems because of it. i had a blaster and i know that the 240 kit is not a good idea for that but i thought it was because it was a 2 stroke and the heat it would produce , i figured since this is a 4 stroke and it has a cooling system that it would not matter and i should have the power i needed to keep up with the 450s or at least beat the new z400s and the kfx 400.
IF ANYONE CAN HELP ME SHED SOME LIGHT ON THIS LET ME KNOW

I would like to know what barry is running in his 400ex :D

440 kits on 400ex's are a BAD IDEA. there hasnt been one single 400ex that I have ever seen hold together with a big bore kit. the first thing to go is usually the crank, then the pistons, valves...etc etc.
the cooling system isnt the issue really. its just that the engine wasnt designed with the extra stress of the 440 kit in mind. can you build a bulletproof 440ex...sure. but how much money do you want to dump into it.


good luck beatin the z400 with the 400ex
the 400ex is air cooled...so i'm not sure what "cooling system" your talking about

THANKS FOR GETTING BACK SO QUICK so i need to take it back down to stock and it would be more reliable,what can i get for it to add power without making a ticking time bomb,what about a stroker kit i heard if u buy the right kit thats the safest way to get an extra 5hp

I wouldnt mess with the crank. Heres what to do, keep your stock rev limiter. The honda crank is a VERY good unit, and it dosent have an issue throwing the 440 piston up and down. 400ex's seem to blow only when there being revved higher then there supposed to.

Keep the 440 kit, put a stock cdi in it, and maintain it very well. A bigger oil cooler and scoops wouldnt be a bad idea.


Jeremy gets a little more confident in his Z every day, i may have to step in and shut him down.

we could do a 300ft video drag.....just for funsies....that might be a good match. honor system on the official measurement of 300ft. i trust ya. let me know a date to have the vid posted. we'll just use the photobucket counter to see the times...if its that close...we could rematch with stopwatches.

were do i get a bigger oil cooler from,there is a guy on ebay that has a 400ex he put an extra oil cooler on his, will that work or would that not work,i have a set of scoops on it already
I WOULD LIKE TO SEE THAT RACE S:S
What kind of set up are u running on your bike Barry?

he was running 2 gerbils and a brass running wheel. he has since upgraded to 2 full grown sewer rats, titanium running wheel, and self lubricating muffler bearings :o S:S

WTF
:blink:

Other than the mods jeremy listed, im running a UNI filter, weisco 10:1 piston, hotcams stage 1 cam, white bros R4 slip on, and some cdi that isnt stock(which i hate). It also is 1 toth down on the front sprocket and im running 20 inch tires.

Jeremy, grass or asphault? Racing someone halfway across the country is gonna be sweet.

i have no asphalt anywhere near where my z is...so, i'll let you pick..grass or dirt. the field i can do it in is mostly hard pack dirt..(where the kids have the grass tore up from riding). so...i'll e on dirt/grass

suspension mods allowed? i.e. ratchet strapping shocks into their compressed state for the races?

I think it should be as is. Like you two just lined em up at riding spot. Then maybe ratcheded.

I dont care about the suspension, i wouldnt mind strapping mine either...

My issue is that I have a feild across the street from my house, but the grass is now almost 3 feet deep. Thats gonna bog me down like a mofo, and my tractor isnt going to cut that down either.

Run your time whenever you can, but dont post it. Ill run my time when my township decides that the grass is too deep and cuts it finally. Could be next week, or could be next month though....

alright...i'll try to do it sometime this week.

i will take winner lol

3rd dibs haha

-Brett-