I fully expect to get flamed for this but here I go...

My 426 is too damn heavy! I never thought I would say it, but it is oh so true. Why would I say this after happily riding my bike for 3 years? I rode a cr125. My wife's bike, actually. It was a tough transition, and a real eye opener. The first thing I noticed was how much I rely on the 426's awesome power. I kept stalling the 125 because I was in 3rd when I should have been in 1st(for that bike.)

There is no way to argue it- Big Blue has the juice!

About 1 hour into the day, I figured out which gear to use and remembered how to use the clutch. From then on, I was riding just as fast as I can ride my 426. Not only that, but I was able to ride much longer with fewer breaks. Now I have to choose which bike I want to take whenever I ride. It is a tough choice!

The Point:

Someone needs to figure out how to get the power of a 426 into the weight of a 125. When they get that sorted out, I know what I will be riding.

That is a good idea.

Buy a new 450. There is tons more power, from what I hear, and there is a lot LESS weight. If you want to have a lighter bike you have to have a lighter pocket book too.

stick the 426 motor in the 125 frame

BBR can do it...:)

Well, I first came to this post cus I thought it was going to be about fat guys like me :)

Try riding a 450. I think you will notice the difference in weight.


Unfortunately we are at that point with the technology that we won't see any real weight loss until the higher-grade metals and composites can be introduced into mass production.

Yes, the 450 is lighter than the 426, but even still, it could and should be no more than 200lbs.

As for the 2000 426, I have one that checks in at 238lbs. However I have shaved everything off of the bike that I could. Things like rim locks, fork guides, covers and guards...etc, (okay, and there’s some ti stuff involved as well). It makes a difference, but it also makes maintenance a bit more demanding.

And if I remember correctly, the factory 426s were 226lbs. So if anything this shows some hope.


BTW - There's an article in last month's Racer-X about a 192lb. 500cc 4-stroke motocross bike that was built back in the 60's. I think it was BSA. Nearly pure titanium.

And Transparent aluminum is not invented yet. I cant wait until the dilithium Crystal engines with warp drive get here

You an go to the Yamaha site and get all the titanium you need to slim it down a few more pounds...

There is plenty to do to get oz's off. After all the best quote I heard on loosing weight on the YZF is

Its not in Pounds But In Grams and Oz's

Check this out

Money can loose weight

If you are a weekend warrior like myself, I don't think that a 450F will satisfy your desire for weight loss.

I've ridden a buddies 450F and I really could only feel the weight difference in the air. It was more "flickable."

Otherwise, it just felt like a well suspended, crisp, and more powerful 426.

For $6000 it is just too small of a difference for me. I'm going to train better instead and wait at least another year or two.

Just my 0.02.

damn....i thought this was a post that was gonna help me lose weight!

Alright buddy heres your flaming you knew was coming-

You can't come to the best manufacturing side and tell us the 426 is too heavy ( hit the gym girly-man :) ). Then tell us you give props to your wife's Honda 125 2smoke, come now? No offense but next you'll be coming to us saying you want a lighter PS2 controller for playing ricky carmichel MX. Alright enough being mean, buy some titanium parts and what not, hit the gym and the rest of us will keep quite about this :D Just kidding with yea I'm at work and quite bored-

Going with a two smoke is a losing plan ask 2007!!

I just heard that depressing new years song in my head :D

i see ego is a fellow treky. soon we will have bikes built out of tritanium with full impuse and shields so RC and travis can't hit each other anymore. but sooner or later the siearra club will assimilate all of us. "We are the Sierra Club. Existence as you know it is over. We will add your biological and technological distinctiveness to our own. Resistance is futile."


Someone needs to figure out how to get the power of a 426 into the weight of a 125. When they get that sorted out, I know what I will be riding.

They Did............ 2003 YZ450F, 231# NO JOKE, feels like my 02-YZ 250F, with a punchout Hemi..........

Hey DaveJ, if your not using rimlocks, how are you stopping the tire from spinning on the rim? Mine spins a little just about every ride.


It's an old trick that the factory guys did long ago.

The tire is now held to the rim by three 3/4" long taper head stainless steel screws on each side of the rim. 6 each wheel.

This lowers the weight, makes tire changing easier and makes for a wheel that is a little more balanced. Additionally, the tire never spins on the rims with these guys in place.

Some guys run four screws on each side, offset for left and right, but I think three does the job.

I'll post a photo if you want to see what it looks like up close.


Hey Dave, yeah I would like to see a photo of that. I was getting ready to add a second rim lock, but if theres other options out there, I'm all for them. thanks.

THAT is the coolest idea I've seen yet (barring the BK mod, of course). What do you ride? I mean, if you ride mainly trails and the occasional hare-scramble, my MX'ing may put a bit more strain on the screws than they are able to handle...however, if you've got a 2-digit SX nubmer, I'm sure they'll hold up to anything I can throw at them.

The 'hopper


I posted the following just a few days ago on the YZ250F side.


When I got the 426 I thought the bike was the best thing on two wheels,,, well in 00 maybe it was. Then along came my 250F and I stopped riding the 426 because of the bulk and brutal power so the things sits. Then came along the 03 E cam in the 250F and life got even sweeter. The 13th I sent off the barrel to have some work down on it so I'm forced to ride the 426,,, I HATE THE DAMN THING It's top heavy noooooo it's just plain heavy everywhere, it's clutch sucks (still some grabbyness) it doesn't turn as well as it's little brother and the starting !!!! OHHHH Man did I ever get spoiled quick with the 03 E cam, I just hate that stock YZF ritual now. Plain and simple I don't like the 426 one bit well, The big power is fun to play with but that's it. Soon as my lil F is back together the 426 gets new plastic & graphics and it's for sale I have no use for it anymore, I almost hate to ride the bike.

I need to ride a 450 and a 250F.

Who is up for a mini TT group ride in the Bay Area? We need someone to bring a 450, someone to bring a 250F and I will bring a 426 and a CR125. Nothing brings it home like back to back rides...

I am going to consider shaving some weight off of the 426. Mods that I would consider:

*rim lock removal(Very cool)

*wet sump

*drill some more holes in the skid plates(?)

*strip all the paint off(JK)

*Lighter fork guards

*smaller gas tank(available?)

*drill holes in seat base

*450 cam(gets rid of cable and lever)

Removing weight up high would make a bigger difference in feel(I think)

Short of Ti or Carbon Fiber parts, what are some other diet mods that don't take away from functionality?


I ride some trail stuff, but mostly the MX tracks. The bike gets some serious use.

Now there are a couple of things to keep in mind here.

First, I go through tires fairly quickly, replacing them often. Mainly because I run soft compounds and prefer the feel of a sharp new edge.

Additionally, on each tire change, all 12 screws are replaced with new ones. And I noticed that some of the screws will have a slight bend in them, which could be from distortion or slippage, although there are no other signs that the tire is moving on the rim.

Sometimes I will also break a screw when removing it, which most likely means it has been over fatigued while riding.

It's possible that you could run a stronger screw, a larger screw, or more of them. But more screws or larger screws means less rim integrity, and I didn't want to mess with that.

Additionally, I have yet to run pressures less than 10lbs as well.

So my point is that I don't think this is a wise mod for the casual trail rider that replaces tires once a year, or the person that doesn't want to be bothered with engineering style maintenance.

So as with all things, it's a compromise in time and energy to the particulars of how you want to bike to ride and feel.


ever go to deep and puncture a tire?

what about resale... how do you explain the holes in the rims?


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