I suspect that the bike already has a Mikuni. As requested before, please show us a close-up shot of the engine.

carb
 

here it is

Nope, not a Mikuni. Here's one: http://www.ebay.com/itm/30MM-MIKUNI-...ab812e&vxp=mtr

hey culcune so with a 12 tooth sprocket in front now what size rear should i got with.
i currently have a 38 tooth?

See how the 12 works for you before worrying about the rear. I was surprised it came with a 37 to begin with. Many of the enduros were the opposite of your off-road bike, and came with 14 front and 56 rears making them run maxed out at like 50 mph when 55 to 60 mph was more desirable for the road. I would guess, with a 12 front, a mid-40 would be what you want for off-road.

FYI there are no external adjustments on the PZ30 other than Idle air screw. Also the carb bowl screws have no heads I had to grind slots so I could use a Flat tip screw driver, to get the bowl off to clean the carb. The top cap also had a rivet that had to be drilled so i could remove it. I have a Mikuni on the way.

Welcome!

I've removed several PZ30's, but I've never seen one like that. Not even a pilot mixture screw on the underside?

It is capped, no external adjustment at all. Kind of pissed me off This is supposed to be an advanced bike and they took away the ability to adjust for riding condition. O well I got mine for a song used.

You'll love the Mikuni.

What Manufactures use Mikuni?

In Japan, most of the big four have used Mikuni at some point. In the dirt bike world, Honda gravitated towards Keihin and Yamaha towards Mikuni.

I've even seen references to Mikuni on HD.

Good, there is a Yamaha Dealership a block away from my house.

If the local Yamaha dealership doesn't have the jets you need, they can likely order them.

How hard is it to jet the carb ? I'm pretty mechanicle good.

welcome from a fellow upstater..... where abouts you at? I'm over in clifton springs....between roc and syracuse....