White Bros E series discs?

[seadub]

I got a YZ 400 with a 420 kit in it.

How many disk should I use? It currently has 12+ the end disk. I have called White Bros a couple of times to no avail. If anybody else has a similar set up, please let me know.

I had the timing set right after I bought it and the jetting is all stock.

Thanks for the help.

[DaveJ]

I have 12 in mine as well, (426). Tried a collection of less but nothing performed better. I also ran it without the disc (wide open) just to see what the performance was like. As mentioned in their literature, it produced the most horsepower but was not spark arrestor legal and was very loud. It would be interesting to see what 16 disc or so would do.