FZR 400 Carb Tuning setting etc....

[kirbster]

Been digging into my recently aquired Canadian model FZR400U. 1988.

Teh bike came with a supertrapp superlight

http://www.supertrapp.com/product_secti ... =425-20160

It had all 8 disks in it. It is a bit loud. It has the stock airbox and stock headers.

Carbs have benn looked through,

Pilot Jet: 20 This i sup two sizes- any pointers on mixture screw settings based on this increase? Stock is 3.5 turns out.
Main Jet: 87.5
Standard needle shape but upgraded to one with 5 clip positions and it is on #3.
Emulsion tubes look like brand new (i bought some Factory Pro to install but will leave teh stock in for now).
Needle valves look good.


Float height seemed way off compared to what i read on here. Rght around 10mm.

The exhaust is very sooty black.

When i had her out back in November, she seemed a bit lean up top but pulled reasonably well throughout the rev range.

Now i was wondering if whoever tuned the carbs was compensating for stock jets by raising the fuel level (dropping float height).

Now that i have set the level to about 12mm, should i worry about being overly lean on top? The increased pilot size should richen up the bottom some. But this could leave the top lean under higher throttle. Correct?

Is anyone here running a slipon with stock exhaust header and stock airbox/filter? If so what have you done in the way of tuning?
As it stands i am tempte dto buy a few main jet sizes (90 and 92.5) just in case i need to do this.

My other option is to remove disks from the Supertrapp to reduce flow (and noise).

Any thoughts from the gurus in here?

I have to replace my carb boots as well, as mine are starting to split. And it is very cold here right now, so it will be a while before i get her started up again.


Any theories would be appreciated.
Thanks