KZ650SR D1 - AIr Screw Location On Carbs

Hi Guys;
can only see the fuel screw to each ? , anyone know were the air screw is 1978 bike

The PILOT fuel screws comes up from the underside and show in the photo.

The PILOT air screws are on the side of the carbs, visible from the front.

I strongly suggest getting a factory Kawasaki manual for your bike. There are free downloads available on the internet. www.zedrider.co.uk/service--owners-manuals.html

Also, find a parts fishe where you can look for parts info such as on Partzilla. www.partzilla.com/catalog/kawasaki/motor...-d1/carburetor-parts

1978 was when they were just beginning to introduce stricter emissions standards and the carbs were all over the place in design. If you have the pilot screw type like you pictured, most the time that is the only mixture adustment. Turn screw out to richen mixture. I believe all SRs in 1978 came with the air screw type carbs, so yours may not be original. As to the rest of the KZ650 line in 1978, some came with air screw type, some with pilot screws, very few even had both adjustments. Late 78 production even went to smaller 22mm piolt screw type. I think all SR though were 24mm air screw, but it was a real transition year for carbs.

Hi RonKZ650 ,

that was my thinking , all the ports on the carbs are solid , only the fuel screw on the bottom are exposed , need to measure the throats now they are back from the cleaners could be VM22SS

Thanks for your input on this matter the Tech Manuals are pants on this issue

Good Fortune!

Thanks Patton, starting to make sence so looking forward to setting them little screws up with size 10 hands

So now we have established that there is only one mixture screw , how do we know what carb is which ie VM24SS or a VM22SS , the air side throat diameter is 35mm the engine side is 24.4mm or thereabouts.
remember this bike is 40 years old and i have owned it 4 months !

and yes i do have the Clymer manual for it ! all the documents say 22mm so why is the dim 24.4mm , different carbs at some point in its life ?

It is very easy to tell whether the carbs are Mikuni VM22 or VM24. Look at the opening on the air cleaner side. If they have the orifice at the 10:00 position they are VM22; if not they are VM24. This assumes the carb bodies have the ribs as shown in the image below. If they do not have the ribs they are not VM22 or VM24 carbs. Ed

Hi 650ed,

so what about these then , the orifice is at 14.00hrs (2 o'clock) the other one is blank for sure , i will look again tonight and photo them correctly

Clive1978 wrote: Hi 650ed,

so what about these then , the orifice is at 14.00hrs (2 o'clock) the other one is blank for sure , i will look again tonight and photo them correctly

It seems Ed has provided the info you need..." If they have the orifice at the 10:00 position they are VM22; if not they are VM24. " That clearly suggests you have the 22's.

"10:00 position" means "10 o'clock position."



I can't explain why the engine throat diameter would measure 24.4 mm unless maybe it's the larger outer diameter instead of the inner diameter where the measurement is supposed to be taken. Or perhaps the carbs at hand are some other ribbed 24mm carbs with bottom located mixture screw (if such carbs exist).

Good Fortune!

So the intrigue continues this side of the pond , see the photos just taken there is a casting there but no port it’s what we call blank