So my wife and went out to the beach and raced it out. Hers is an 03 400ex and mine is an 04 400ex. Mine is faster by about 4 bike lengths. I also out weigh her by about 100lbs.......The only thing we have done to both is went one tooth down on the front sprocket. I had no troubles keeping the front end down, 2nd gear starts are easy. Hill climbing is much improved. Alot of hills it seemed 2nd was to low and 3rd was to high. Now I can climb almost anything in 3rd. All of this is in the sand with stock knobbie tires. Hope this info helps someone out sometime down the road.

 

Did you try racing her where you were riding her bike? I have 3 400exs and the fastest one is always the one I am riding no matter who is on the others. I weigh about 85 lbs more than my girlfriend and beat her every time. Just wondering if this is a case of a more skilled shifter who knows the best shift points.

/Jon

 

I thought I heard somewhere that the 04's were faster from the factory... something to do with the 450's being out Honda made them alittle faster.

 

one thing son...all bikes are diffrent same years even...what ur saying could be true but keep that thought in mind.it would be nice if it did crank a lil beter.IMO.

 

the 04s have a bigger carb

 

The 04's do have a bigger carb, 35.5mm vs 38mm carb, but there is no way with equal riders that the 04 would win by 4 lengths. With you weighing 100lbs more than your wife that would make the difference even greater. You either got a fast 04 or she has a slow 03 400EX. A bigger carb would not make the 400EX 4 lengths faster than a 03 and below 400EX.

 

I've heard that the 2004 has something like 30-32hp compared to 25-26hp of the previous years.

I've also heard that the 38mm carb according to Hondas website is a typo and that they still have the same 35.5mm. Is this so, or do they REALLY have a 38mm in them now?

 

The only thing I can add to this thread is I hear everyone (including 400EX owners) talk about how much faster the Z400 is but when I and a friend who also has an 04 EX race the Zs (all 3 of them), they are just as fast and equal so there's got to be something different with the 04s.
Also, I heard the 04 EXs have 29hp compared to the previous years 27hp.

 

We did alternate bikes and the 04 was always the winner, except for one time when she missed a gear. She actually got to ride my 04 before I did and when she brought it back she said it felt alot faster then hers. We run 92 pump in both, one tooth down on the front sprocket on both, 3lbs of air in the rear tires. I def. would not consider hers slow because I have ridden a friends pipped 400ex and his isnt alot faster then hers....I guess I'll have to race the pipped one, it's on 02 or an 03 and see how it does against my 04.

 

i am trying to get a 400ex and maybe i should just buy a 2004..lol