426 external stator, how does it work

I was reading the post on making the 426 street legal.How does an external stator work.What is involved in installing one.

One of the replies mentions an external stator verses a E line stator. How bright of a light can you install with the external type. I am in the process of making my 426 street legal and need all the help I can get. To get better top speed I was thinking of installing a taller 5th gear. Does anyone have any advice on that subject.


I purchased an external stator form Baja Designs. I think they said it would produce 120 watts. This is more than enough to run all your lighting.

The external stator uses a seperate flywheel that is bolted to the original. You will still use you original stator to run power to your coil. Another coil is located inside the stator cover. To install simply lay you bike on its right side. Remove shifter. Remove the flywheel cover. Remove flywheel nut. Install the flywheel weight. Torque bolt. Install new cover. Install new shifter. This assembly sticks out farther than stock, but it very easy to get used to.

About the 5th gear. Depending on how fast you want to go and what other riding you do you could always just change front sprockets. With 14 50 gearing on my yz I can cruise at ~50. I just purchased 15 49 sprockets. I tell you how they work out.

I think the Eline deal will only produce ~45 watts (not sure). This is not enough if you want to run high powered lights. For Acerbis headlights you can get a bulb w/ 60 watts low beam and 100 high.


[This message has been edited by npuza (edited 09-15-2000).]

I think going to a WR 5th gear is a good idea. Using gear ratios kindly provided by someone on this forum:

WR 5th is almost a 12% increase over YZ, so with stock sprockets (14/49) you will be pulling 8,200 rpm at 75 mph (give or take a worn knobby). But with the YZ 5th gear you will need an additional 1,100 rpm to go 75 mph. Yikes. Taller gearing on sprockets and 120/90/19 tire may help a bit but the biggest help will be the WR 5th. I don’t imagine any amount of gearing will get you below 7k rpm going 75mph. So I don’t guess you’ll be spending much time on the freeway.

Both are overdrive or less than 1.0, YZ is .952 WR a taller .840

Gaps between gears, YZ, YZ w/ WR 5th, WR

1st to 2nd| 18.7%| same| 28.3%

2nd to 3rd| 14.8%| same| 24.2%

3rd to 4th| 14.6%| same| 20.0%

4th to 5th| 12.7%| 23.0%| 20.0%

(sorry about my table, didn't translate to good did it?)

The upshot of all this is that w/ WR 5th the gap will be just a little bigger than the normal WR gap.

I don’t know how difficult it would be to swap the gear yourself but obviously you need to open up the motor. I have read some other posts on this subject so hopefully someone who has swapped his top gear out will enlighten us.

I have considered doing this myself but I am a bit leery of that 23% gap, I do use 5th gear quite a bit on trails and in races.

I hope this is accurate (I didn’t split my cases and count teeth to verify, plus my math sucks) and hope it is helpful.

[This message has been edited by Hick (edited 09-15-2000).]

Thanks for the replies. Im not shure I want to go to all the trouble to make the modifications I was asking about. What I would really like to have is a wr426 instead of the yz426 that I currently own. I love the yz but what I really have in mind is more of a dual sports bike. I live in a rural area where there is lots of riding near my house. There is a bit of a problem in that a sheriff lives in my subdivision. One ticket would probably pay for the mods I previously have mentioned. Thanks again and I will keep you posted on what I do.

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