Ok I'm buying my motor interns for my 400ex......

I want a 440 kit...

I was also planning on a xr cam but somebody told me that it would make me lose some low end....... He told me that a xr camed 400ex cant take off on a wheelie like a stock 400ex.... It is harder to drive in woods cuz of the low end..... Is that right ??????


OK AND WHERE IS THE BEST PLACE TO BUY A 440 KIT ????? and IS THERE ANY DIFFERENCES IN 440 KITS OR THEY ALL ARE THE SAME ???????

 

White Bros. are the guys to call. They have fooled with that engine since the XR400 came out giving them a head start when the EX came along. The only source I use for customers and recommend is White Bros. for the Honda 400EX. Best service of any in the industry. Also been around longer than the other guys.

 

the place to buy the 440 kit (the basic kit, piston, sleeve, gaskets) is Rocky Mountain. ITs only 209 and its the IMS kit with JE piston.

I have the XR cam and it took some getting use to but I now that I am use to the cam, i wouldn't trade it. The bike hits really hard in the midrange and revs to the top quick. The motor wants to be revved much more with the cam then stock. Its true its a bit harder to wheelie, but still EASY. If you have the money to spend, sure buy a good aggressive cam and upgrade your valvetrain, but if your looking for a cheap, durable cam, go with the XR.

 

If I keep the stock cam.... My 400 is gona feel the same with more Torque and hp.....

Kinda like putting a B20 block on a gsr.... but keeping the stock cams.... right ?!?

 

Yeah, but putting the XR cam in would be like putting the ITR cams and valve train on top a gsr motor. Makes a bit more power up top but is still reliable.

 

but with the XR cam I'm gonna loose some bottom end right ????????

 

If you keep the stock cam and bore to 440, almost all your gains will be low end. If you put a cam in you will broaden your powerband. My 440 has unreal low end and it has a full race cam. It also pulls all the way through the powerband. I really cant think of anywhere that it lacks power, and that is pulling 15/36 gearing with 18" holeshots.

Adam Smith

99 400EX

 

I would say you lose some extreme bottom end,,,like below 1500 rpms. Not like you run below that very much, but the couple times i did while climbing, i noticed the bike didn't pull like it use to. But i would DEFINATELY recommend at least the XR cam for the 440 kit. The midrange and top end hit are a big difference from the stock cam.

 

I think I'm gonna get the 440 kit and if I still want more power get the cam later on. I know it dont make sense but I like the OEM powerband.......... So if I'm happy with just a 440 kit...

 

It would make no sense to just put in the 440. Your results would be minimal. Take the time while you have the motor apart and put in a good cam, maybe a HRC cam, or a GT THunder cam, at least put in some cam. If your worried about losing low end change pipes or gearing.