YZ426 for the trails

Dont know how many of you saw my first post regarding my '01 YZ426, but I will again mention that this is my first bike of any kind and I have basically no experience whatsoever.

I have done quite a bit of reading on this forum regarding mods to make the bike more trail friendly since its proabbly never ever going to see a track.

What I want to do is get the bike happier going a bit slower until my confidence builds up and I am able to safely get through the trees going a bit faster. As you all know the bike is really unhappy going slow, and to me the throttle seems extremely twitchy as the engine gets up to speed really, really fast. I have spent most of my 3 rides trying to get comfortable standing up all the time, and trying my best to keep my weight over the front forks, but I am having a hell of a time keeping the front wheel on the ground.

I would really like to change the final drive from a 14/47 to a 13/50, but I am worried that although I can keep the engine rpm up a little higher while going slower, I am going to have even more trouble keeping the front wheel down.

How much will a 10oz flywheel weight help smooth out the twitchy throttle. Will a flywheel weight make much difference at all? Would you guys reccomend more or less weight?

I havent pulled anything major apart on the bike, but I am thinking I will just turn the weight myself as most of the kits I have seen on the internet retail for $160 to $200 USD and they consist of a $5.00 piece of steel and about 30 minutes setup and machine time.

Does anyone out there have a weight kicking around thats not installed that could grab a caliper and give me some basic dimensions?

Your guys advice and reccomendations would be greatly appreciated.

I absolutely love my YZ426 on the trail and occasionally still on the track. You'll find that a FW weight will tone down that wicked off idle punch to a more usable, trail-friendly pull (12oz. works great). Next mod should be your suspension...go ahead, bite the bullet and fork out (pun intented) the cash for having them reshimed and sprung, it'll be a different bike. Then I'd get a steering damper so you can relax your arms. Some extra protection like radiator guards and skid plate along with bark-busters and you've got an awesome woods machine. :bonk:

I would recommend buying a complete new flywheel so you can always swap back to stock if you wish. (or sell it to someone like... Goosedog):bonk: I had a 12oz on my 426 and it worked better for the trails and the MX track ever now and then. I tried chaining my gears as well, but that will only the bike have more power down low. It will only make things worse. If you are only trail riding, I would consider maybe even getting 14oz. It will smooth out the power and stop you from stalling. It is worth the $200. Just get one, you will like it.

Here is were I purchased my flywheel. Steahlyoffroad.com and here is a flywheel size chart.

When I first called Steahly they recommended the 12 or 14oz, I chose 12 knowing I'd still mx it a bit. Also 13/51 is my current gearing and along with the FW weight I hardly ever stall it anymore.

Yeah and like Dano says definitely get a seperate aftermarket FW, that's the way to go not only because you can swap it back out but also you never have to worry about an add-on weight coming apart.

I tried chaining my gears as well, but that will only the bike have more power down low. It will only make things worse. If you are only trail riding, I would consider maybe even getting 14oz. It will smooth out the power and stop you from stalling. It is worth the $200. Just get one, you will like it.

So thats a negatory regarding changing the final drive? It seems to be pretty much the first thing that people sugest to me. I hadnt really considered going for a complete flywheel though. I think you guys are right. It would allow me to go back to stock when I want to sell the bike, which will probably be at the end of this season, or next season.

how difficult is it to install a flywheel, and what tools do you need?

It's not hard.

You must have a flywheel puller.

A flywheel holder is handy, but not mandatory, and a torque wrench is a good idea.

Also don't forget to do the 450 autocomp cam switcheroo.....that's right up there with doing your suspension for the 426.

Good thing it's only money, right? :bonk:

how difficult is it to install a flywheel, and what tools do you need?

I have used the clutch holding tool for a few years, I recently purchased a air impact ($40) to remove the flywheel nut from home depot and would have to say that it is worth every penny.

(or sell it to someone like... Goosedog)

Dude, I'm such a goober. I forgot it was yours I bought. :bonk:

Dude, I'm such a goober. I forgot it was yours I bought. :bonk:

Just a little jab there... glad you are still enjoying it.

No plans to do the Autodecomp mod as I have absolutely no trouble starting it at all, any time. Side hills, or after its been dropped while its hot. It fires up first or second kick, no problem. The starting ritual is cake.

I will as again though.... you guys dont reccomend changing the final drive as that will make it even twitchier?

No plans to do the Autodecomp mod as I have absolutely no trouble starting it at all, any time. Side hills, or after its been dropped while its hot. It fires up first or second kick, no problem. The starting ritual is cake.
Yeah. That's what they all say. The story changes abruptly once they do the mod, though. :bonk:
I will (ask) again though.... you guys dont reccomend changing the final drive as that will make it even twitchier?
Lowering the gearing will obviously make it easier to lift the front wheel or overpower the rear tire in low gear, but if your interest is in low speed trail riding, it still may actually make the bike easier to deal with. You'll have to watch the throttle, of course but the engine will be somewhat more content to tool along through the tight spots without all the clutching and raising the revs, etc. I drop the gearing on my '03 when I ride the tighter trail areas.

Thanks very much for your reply Gray. I think I will get a set of sprockets and give lowering the final drive a try. Hopefully a new heavier flywheel will help take a bit of the initial hit away from the bike and make a lower gearing a bit easier to deal with.

Right now I am only interested in going fairly slow, and i still have two gears on the bike I havent even touched yet, so if I get better and faster I still have some room to improve. If I one day find that I am running out of gears, the sprockets I am taking off are basically new so i can just put them back on.

Thanks for everyones answers and suggestions. :bonk:

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now