KZ650sr jetting advice

Hey Y’all!

I recently got a ‘79 KZ650SR. The previous owner lived in a higher elevation area about 5,000 ft above sea level. He had the bike rejetted at a shop out there but I haven’t had a chance to peek at what it’s been changed to yet. I live in a state at a much lower elevation only about 1,000 ft above sea level so I’m betting it’s gonna be a bit lean for out here. The bike is slightly modified with mesh pod filters and an aftermarket 4 into 1 Delkevic exhaust but everything else motor related is stock. I would just like some input from others on where to start as far as making sure the bike is jetted in a way that will run best for general riding. I’m not an aggressive rider on the street; rarely take my bikes to WOT for extended periods on public roads. Don’t plan on riding in temps below 40* Fahrenheit. Honestly is stock jetting probably fine for what I’m after? Any advice is appreciated. 

What is the build date for your machine? The models built (Jan-Jun) of 1979 are actually 1978 model year machines. This is true for all the different models offered by Kawasaki. If your machine is a 79 model year  and was intended for the US market it would of come stock with accelerator pump carbs. Which stock were jetted leaner than the non pump carbs were.

I do not know this for fact, but the change in jetting for higher elevation would of most likely resulted in a smaller main jet than stock. The fact your machine has pod air filters and a 4 into 1 exhaust system most likely would of created a lean mix over that of the stock settings. If you have not done so as of yet I would suggest you check out posts by zed regarding the air corrector jets he sells for use with pod filters or stacks.

How does the machine run with its current jetting? Until you find what current jetting your carbs have you will not know if changes are required or not. 

 

gd4now wrote:

What is the build date for your machine? The models built (Jan-Jun) of 1979 are actually 1978 model year machines. This is true for all the different models offered by Kawasaki. If your machine is a 79 model year  and was intended for the US market it would of come stock with accelerator pump carbs. Which stock were jetted leaner than the non pump carbs were.

I do not know this for fact, but the change in jetting for higher elevation would of most likely resulted in a smaller main jet than stock. The fact your machine has pod air filters and a 4 into 1 exhaust system most likely would of created a lean mix over that of the stock settings. If you have not done so as of yet I would suggest you check out posts by zed regarding the air corrector jets he sells for use with pod filters or stacks.

How does the machine run with its current jetting? Until you find what current jetting your carbs have you will not know if changes are required or not. 


 

As I understand it Aug78 - July 79 is "79 model year" Aug 79 on wards is 80 "model year" (next model year starts after summer shut down)