Pumper Carb for XR400

[Chugger]

Anyone tried the pumper carb upgrade for the XR400? They come highly recommended from XR's Only, but of course they sell them. Any thoughts?

 

[njw]

If you haven't already, this is an interesting article on XR400 mods with a discussion on the pumper carb.
http://www.justxr.com/info/xr4report.html

 

[Wolf]

Love it

I have a pumper carb on my XR and absolutely love it.
It makes the XR a totally different bike and it is almost unfair to compare it to a stocker. I bought mine from XR's only, they were great to deal with.
I put my XR next to any DRZHhhhhhh...;) If you do some suspension mods and upgrade your pipe, you have a raceable mount.
It simply gives it power and snap everywhere. I was reluctant to buy it at first, but now I think it was the best thing I could have done (except for the fork brace). I was going to sell it and get one of them orange things:scream: ,
but now she's a keeper.

 

[mtngoat]

good article njw, thanks for the post:)

I'm considering the Mikuni too

 

[Wolf]

Everything in that article about the pumper carb is right on. It is a huge improvement and well worth the money. I currently run a e-series pipe with it and it is too loud, however, I like the gains in the middle. I am trying to come up with a solution, i.e compromise as far as noise goes. I don't think it is any louder than any YZ, but they are too loud anyway.
That 430 kit described in that article sounds interresting too. :cool:

 

[michman]

Reading this guys article was like reliving what I have just finish doing to my XR4. I did purchase the Big Gun System first then the pumper carb. I could not believe the difference it would handle the whoops better and the thottle response was crisp. I just got my mototr back from XRS ONLY and had it gone though with the 430 kit and there mild cams and it is unbelieveable what this bike transformed into. In all I think you will be very happy with you purchase of the carb.

Mike

 

[Chugger]

Cool. I guess I'll order the Carb. I also want to get the SRC Steering Brace, Scott's Damper and a RaceTech job done on the suspension. $$$$

It should be pretty cool when I'm finished.

Thanks for the input!

 

[Handl-it]

Mikuni carbs work great! I havent seen a dyno report testing engine performance with it yet. My engine rev's much faster and easier now. Just for fun I also put in a 10 to 1 piston. My 98 came with a 9.3 to 1 stock, this gave it some more grunt. Overall with these cheap mods, less than $500 it runs much stronger where I want it.

 

[Rodzilla]

Man I want to do this, I aready have all the other goodies, Suspension, Damper, Pro-Tapers, SRC brace etc...

The carb is the obvious next step, but geeze I still owe 2k to the bank for my bike an I really want to know if Honda is gonna update the XR soon (and give us the bike were all TRYING to make, from the factory)

We still have a weight issue (after riding my buddies YZ250f I have to admit it)
Of course it makes us much tougher throwing that weight around!

 

[Wolf]

If you can deal with the weight (It's no heavier than a DRZ or WR400) you've got a winner for the woods. Right now I can't see myself trading the XR for any other WOODS 400.

 

[mtngoat]

I'm with XrWolf.

All us XRnuts have spend a lot of time and money to refine our "base-machines" into a bike uniquely suited to our personal and riding preferences.

As enamored as I am with several new bikes, I don't think any new "base-machine" will cut it for me; most would require a lot of mods, short of maybe the KTMs.

I also like the simplicity, relaibility and friendly maintenance design of the XR, which gets compromised in maker's quest to improve performance, especially with track bikes.

As an all-around woods, trails, & desert bike, with a lot of aftermarket goodies to tailor performance, they're hard to beat

I'll be the first to admit there's owner's bias.

 

[Rodzilla]

Wolf, don't get me wrong. I LOVE my '00 XR4 and have logged a ton of miles (pushing the 6k barrier) Baja, Moab you name it. and yes the XR is not really heavier (by much) than the bikes you metioned, but it's definatly down on power compared to both. Yes the XR is perfect for my type of riding. But I just started to ride Hare scrambles and Every other bike out there passes me in the straights, WR, DRZ it does not matter. 5 th gear pinned and it feels like I'm standing still.

My best friend/riding buddy and I are almost exactly at the same skill level. We both ride XR4's set up identically (actually they are 5 numbers apart on the VIN's) I'm faster in the tights, he's quicker in the whoops/Straights (he also weighs 30 lbs. less. When we ride we are always within a second or less of each other. And we're usually bumping tires.

He just swithced to a YZ250f, Same HP as our XR's but 30lbs less (call it 60lbs if you include his skinny butt) and now I have trouble just keeping his rear tire in sight. Yes it's the rider not the bike but.. when your riding equal suddenly gets substantially faster because he's substanially lighter you gotta start to wonder.

Guess I just gotta quit whining and get faster!:p :p

 

[Wolf]

I agree 100%. A stock engine and carb XR will in not keep up with a YZ.
My point really only applies to modified XR's. Get the pumper carb and you will see what I mean. No it still does not have top end like those blue things, but then again I don't attempt to rev it that high anyways. I think that some of the "XR Hybrids" out there will smoke other 400s with a smile. I bet mine would stand a fair chance against any DRZ or WR. And if it doesn't I'll have to check into a Big Bore Kit.:D
If I had to buy a new bike right now(...I'm dreaming...) I would probablyhave to buy a KTM or VOR unless I go back to a 2 stroke:o