Rebuildind My 400ex

[FLSTF]

I had to rebuild my 400ex. I went with the 440 kit with a wiseco 12.5.1 piston. Hotcam stage 3. Kibblewhite +1mm intake and exhaust. port and polish. and a 450r carb. I can wait to get it back together!!! I'm waiting on my cam to get here and I'll start putting everything back together.
What kinda H.P. do you thing I'll get? Can I bet 450's?
Thanks!!
FLSTF

[PaRedneckRiders]

not sure on the hp but u should b able to beat stock or mayb lightly modded 450s
u should keep us updated with some pics

[FLSTF]

add some pics of the tare down

[FLSTF]

more pics of tare down

[FLSTF]

more pics of tare down

[FLSTF]

Anyone know if the heavy duty head studs will fix my problem with blowing head gaskets?

[sheldo]

yes hd studs will help

[TRX01]

yes the HD studs will deffinatly help with that...the HD studs are stronger and the stock studs are weak and stretch out......obviously when you compare the HD studs to the stock studs the HD studs are way thicker

[Pipeless416]

the stock studs do not stretch any significant amount. the threads in the cylinder pull out.

[slightlybent47]

I’d say you’ll end up with somewhere in the 40- 43 hp range. With stock being 26-27, that’s a nice gain and you will love it. Those mods should give it a lot more power and throttle response.

[FLSTF]

Originally posted by slightlybent47
I’d say you’ll end up with somewhere in the 40- 43 hp range. With stock being 26-27, that’s a nice gain and you will love it. Those mods should give it a lot more power and throttle response.
Thanks!!! I'm really looking forward to getting everything back together.

[FLSTF]

Cam will be here today!!!! I'm going to start assembling everything back together. Is it ok to use a synthetic oil in these engines with a wet clutch?

[tedescom]

I would make sure that the oil you use is for wet clutch applications. I would check with the dealer to see if they recommend a certain type.

[gtt416ex]

use conventional motorcycle oil (Honda GN4) for the break in period and the first oil change. Synthetic oil provides too much lubrication and won't let the rings seat properly.

[jcs003]

probably 32-35 HP. i had a JE 435 high-comp kit with all the porting and cam. every bell and whistle and it dynoed at 35 HP and 33 lb/ft or torque. was great for XC. i did good til i had to quit to go to college.