Jetting Question for 1982 KZ 650 CSR

Hey everyone.

First of all my paperwork for the bike says that it is a 1982, but the VIN sticker says that it was manufactured in 9/81. The VIN # is JKAKZEH12CA015164.

My real question: I'm putting pods and a free flowing muffler on the bike. I want to use the Emgo filters, but I've heard mixed reviews.

What model are my carbs, and what size jets and needles should I use? Any advice would be awesome, since I'm having a really hard time finding numbers to use. Thanks in advance.

Anyone have any suggestions? I'm not even sure where to get the jets. Dynajet has a kit, but I'm not even sure if it's the exact right one. Any help would be great.

Hello KZ650Cafe and Welcome to KzRider forum. We're glad you're here!

Regarding the 9/81 manufacture and 1982 papers, it is normal for a 9/81 build date to have a 1982 title. For example, current year automobiles are often actually manufactured during the year before.

If some unsolicited advice may be forgiven, would review all the pros and cons about using pod filters before doing away with a stock airbox and filter. Could gain most of the benefits (and less negatives) by just using a K&N filter in an existing airbox to accomodate the freer flowing exhaust.

Adding freer flowing exhaust and intake does indeed often require rejetting, but sometimes not, and with some setups less than others. Being uncertain about the 1982 KZ650 CSR, will defer to others with better knowlege about carb mods for that specific model.

In general, however, before randomly upsizing the jets based on some rule of thumb, I would recommend first actually test-running with the existing jets (note engine performance throughout the range), do a spark plug reading, and go from there. Sometimes the pilot jet will be okay as is, but needing a larger main jet, or vice-versa. And it is often unnecessary to adjust the needle clip position.

Regret not having better advice on your specific application. But pods do look really cool, so "Good Luck" with whatever is decided.

Forgot to ask -- is it known whether the existing carbs are CV (constant vacuum) style or manually operated throttle slide style?

Kawasaki.com shows both type carbs were used on 1982 KZ650CSR (if I'm reading correctly).

As far as I know, most of the 82 model 650s were BS32. Pods will work fine with this carburetor but the carburetor needs to be rejetted. I am too lazy to look up the specs on kawasaki.com. The BS32 has a large round top. The 24s that might have been used (mechanical slide carbs) have small tops retained by 3 screws (not four like the BS32). These would be pumper VM24s and would also need to be rejetted. First we need to determine which type is being used and second, the owner needs to look up the specs... needle jet, jet needle, main and pilot jets and then I could take a stab at how to rejet for pods.

Thanks for the responses, guys. My carbs have the round tops, so I guess they are the BS32.

To found out the existing jet sizes, is there a place I can look online, or should I just crack the carbs open and look at the numbers printed on the jets?

kawasaki.com has parts diagrams for your bike which list the jet sizes. The needle jet is pretty much a given as you won't have much access to alternate needle jets. This is the part that protrudes up through from the float bowl and is the brass orifice that sits in the bottom of the venturi. It meters and mixes gas with air and allows the diffuse mixture to be drawn into the combustion chamber from the main jet and jet needle. On the other end, in the float bowl the main jet screws into the needle jet end and there is a brass washer between the jet and needle jet. The main jet meters fuel flow to the needle jet. The main jet will need to be changed. I think it might be a #107.5 for your bike but you can confirm. The pilot jet sits adjacent to the main jet in each carb bowl. It is down in a well. If you attempt to remove this jet, make sure you have the appropriate flat-blade screwdriver to remove it. These jets will like be #37.5 and will have no small holes in the long section. You will replace them with BS30/96 type Mikuni pilot jets which DO have small holes in the sides along the longest section. These type work as well as the original type and are easier to find. You will definitely want to use a #40 BS30/96 type pilot for the rejet for pods. As far as the main jet, here I am not positive. I have rejetted these things in the past but can't remember the number of the main jet to be used. I am thinking about #135 or #137.5 main will be right. Before purchasing, please confirm your existing jet sizes (actual and not reading something from a parts diagram). It is easiest to rejet with the carburetors off the bike but I guess it would be possible to rejet with them in place... You can get the correct jets from www.z1enterprises.com -

Great! Thanks alot. The bike is already taken apart and the carbs are off. I will dig into it tomorrow or Tuesday, read the jets, and order the new ones immediately thereafter.