Carburetor question on this bike please

[kelly5150]

I have several motorcycles, this Viva 250cc Preditor being my only dirt machine. I am no carburetor genius so I need some help here. This bike comes with what I believe is the PZ30 carb. I can plainly see the idle screw on the side, the one with the spring attatched, but where is the air-fuel mixture screw ? Is it the little brass one under the carb directly in-line with the intake manifold of the carb?
I have a 38mm Mikuni on my Norton Commando , but this PZ30 is nothing like it to go by .
Any help please from or gals that have this same carb. I sure would appreciate it . It runs really strong and good, but it needs to lean out a bit according to my NGK Plug .
This si the exact same bike they sell on E-Bay from Family Motorsports, and I KNOW you guys and gals have these bikes , so someones got to know this info, right ?
Also, I would like some advice on air filter mods, like I want to buy a K&N filter like my Harley and Norton have, it adds a wonderfull horsepower boost right out of the box , but I wonder how to do this with a plastic airbox on this bike ? Should I eliminate teh box and run the filter that way or mount the filter in the box ? The little filters they have on thsi carb are a joke and there is NO WAY this machine is getting the right amount of air here . Especially with the seat installed over the air-box too. This has got to change, any ideas ????

As you can see from my photos , the bike looks pretty nice ( too clean ) as it is. I hope to upgrade some stuff soon and will post the progress, pics and all . I will get some miles on it this weekend too for sure, in the mudd I hope . My property is two acres and I am going to tear it up !
Does anyone know of anyone making an aftermarket exhaust header for this bike ? The Silencer is way nice, but the pipe could be better and stainless I hope to find .

Anyway, have a great day , Kelly out !

[ejcycles]

Kelly
Yes the small screw under the carburetor between the float bowl & intake manifold is the idle air mixture screw. The carburetors are either copies or they made by Keihin. The one you have being it says PZ30 on it, is either a Keihin or a carburetor that Keihin made for another company. There are a couple companies out there that make a fair copy of the Keihin, but some people have had trouble with them.
Yours should give you no trouble, unless fuel was left sitting in it after they test ran the engine or you let fuel sit in it for more than 30 days. It sounds as it is OK, just some minor adjustments.

Air filter mods: you will need to remove the complete air box for this. K&N stay away from unless you buy the sock that goes over it, if you are riding in really dusty areas. I suggest using a UNI foam pod air filter, oiled correctly, it will keep more dirt out of the engine than a K&N. I keep them in stock at my dealership.

[kelly5150]

Thanks Bruce, will give that a try on the carb, it is only off a tadd bit , but I want it perfect of course.
Will go check out your web-site on those filters , just not familiar with your product .
I live in WET, CRAPPY, COLD Washington , no real dust to speak of.
Would I need to remove the airbox if I use one of yours too?

Anyway, thanks and have a great day, Kelly out :D

[katoranger]

The UNI mounts up just like the K&N. Both are the pod style.

You will need to remove the airbox and mount the filter directly to the carb.

The UNI foam is much more effective at keep dirt and dust out than the K&N. K&N are great for street rides.

Allen

[ejcycles]

Hi Kelly

UNI is not my part, UNI is a manufacturer all it's own, as is K&N.

I am a dealer that provides Service & Parts, along with selling motor vehicles. I sell all kinds of OEM & Aftermarket parts for almost all makes & models of motorcycles, scooters & atv's, vintage to current. No I can't keep everything in stock as that is Impossible for any Dealer to do. I keep in stock what sells, as most good dealers do in their area.