best mod?

[nicktrx400ex]

i have a lilttle bit done on my 400ex what would be the best mod to do to get more power and a little bit of speed im wanting more power like in the whole bottom - top end anybody know of one?

[zrpilot]

Do your 426kit and add a cam... big difference!!

[250X_project]

Well I See you have a bigger front sprocket and a rev box so unless you want to go more drastic in those 2 ways , tire size is your only other option for speed.....

For power I would definitely go for a good cam and HD springs. If you go the big bore route, I don't see why to do a 426...I'd do a 440EX, I don't think they need case machining. That would be the only reason I could think of to opt for the 426cc.;)

[zrpilot]

Originally posted by 250X_project
If you go the big bore route, I don't see why to do a 426...I'd do a 440EX, I don't think they need case machining. That would be the only reason I could think of to opt for the 426cc.;)

The 440EX needs a re-sleeve, whereas the 426 can be a simply re-bore/hone

Some would say that even the 426 should be re-sleeved, maybe.

With the Hot cams stage one or stage two, stock springs that are NOT worn out would be fine.

[250X_project]

I don't know if I'd trust that or not. It would be 3mm over stock. Yet I forget they offer an overbore that is .120 over which must be fine then. Just don't try to bore to a 440.... :eek2: