WR 450 crank position sensor

[Storbeck]

Hoping to get a bit of advice from the teams who have run a Yamaha WR450 engine. I'm scheming to put efi (microsquirt) on one in a bike, not fsae car that's why this is in "off topic"

What did you do for a crank position sensor? Use the stock one? It's only one "tooth" as far as I can see, not sure if that's enough, seems to work on the stock bike though.

Or maybe not, I see a wire on the wiring diagram going from the AC magneto directly to the stock ecu. Directly as in not going through the rectifier/regulator first, is it possible they're using the AC signal from the magneto as kind of a crank position sensor?

[Storbeck]

Hoping to get a bit of advice from the teams who have run a Yamaha WR450 engine. I'm scheming to put efi (microsquirt) on one in a bike, not fsae car that's why this is in "off topic"

What did you do for a crank position sensor? Use the stock one? It's only one "tooth" as far as I can see, not sure if that's enough, seems to work on the stock bike though.

Or maybe not, I see a wire on the wiring diagram going from the AC magneto directly to the stock ecu. Directly as in not going through the rectifier/regulator first, is it possible they're using the AC signal from the magneto as kind of a crank position sensor?

[Jetser]

What we did (Delft) is lathe the first 20 mm of the outside of the flywheel. Diameter becomes a little bit smaller and the original tooth is removed. Then lathe a new ring, press the ring on the flywheel. Then put the flywheel in a milling machine and machine 36 teeth (one missing teeth) or any other pattern your efi supports. The stock sensor can than still be used.

Hope this helps

[Storbeck]

Thanks for the response Jetser.

I figured it would be something like that, which is what I was afraid of since I have no mill or lathe.

Anybody else?

How do you know how many teeth are needed?

Guess I need to study up a bit (I was a chassis/suspension guy back in my FSAE days).