O-Ring sizes

I’m trying to determine o-ring sizes for a VM24SS carburetor (w/accelerator pump), '79 KZ650. I can still order these parts but what I’m looking for are actual measurements. When I replaced o-rings 3 years ago it didn't occur to me to measure them before the installation. This question keeps coming up in my circle of KZ friends. Just wondering if someone can help me out? Thanks in advance.


Kawasaki part numbers:

• 16038-022 "O" RING, Air mix screw
• 16038-016 "0" RING, MAIN JET
• 670B1509 "O" RING, 9MM, Choke/starter plunger

I contacted Sudco, Kawasaki, 3 distributors and 2 local dealers and the question remains. And they all are wondering the same.

Does anyone have a recommendation? I understand it will be a JIS specification and gasoline/ethanol tolerant. Sudco carries a Mikuni O-Ring Kit (but unknown for what carb models) and there are endless metric kits available.

Figuring out O-ring size needs isn't super hard. They are sized by ID and thickness.

There are lots of O-ring calculators on-line as well. You need to measure the O-ring groove OD and the ID of the hole and plug these numbers into the equation. www.efunda.com/designstandards/oring/calc_oring_radial.cfm

Viton is best for gasoline but nitrile is okay as well. I've used both with good results. I've assembled O-ring kits this way for Mikuni BS, VM and Keihin CV carbs. I can't tell you the sizes needed off the top of my head though, sorry.

Closely guarded secret so they can charge 3 or 4 bucks apiece....... I goggled the numbers and Z1 shows the size on most.... looked there first but only found the choke plunger screw in there website, others were under google and them..... Jets R us has a cross reference chart that shows the 29mm smooth bore numbers and sizes so I was able to get those but not so much these.

Z1 shows for the 16038-022 air screw ring at 2.5mm inside with a 1.5mm thickness...... the 16038-016 main jet ring at 5.3 inside and a thickness of 1.85 and the 670b1509 at 9mm inside and a thickness of 1.9mm. A few have searched on here before too (you'll see them under google search)....... Patton and a few others searched for the air screw and come up with very close to the same size years ago.

Go to McMaster-Carr for o-rings. You can search by size and material and for what you'll pay for one or two you can get 50.

Thanks. interesting to find the dimensions on Z1. When I started searching they had the old website up and the dimensions were not shown. Ok - now I have a reference. Thank you.

I'm getting the O-rings from www.theoringstore.com because of selection and information. McMaster-Carr is also a great source.

Metric o-ring kits have sizes that are either the same as stock or close enough. I got a Harbor-Freight metric nitrile kit for the bleeder pipe, drain screw & pump nozzle o-rings. Viton o-rings may be better. The only sizes the HF kit didn't have were the starter plunger o-rings & the tiny air screw o-rings. The starter plunger o-rings have a large ID but thin cross-section. I got those from the dealer. The HF kit has come in handy for other stuff. forks. fuel tank. etc.

Looking for O-ring kits for Vm 26 carbs I ran into this guy and took a chance.

www.cycleorings.com/

www.cycleorings.com/VMkit.html

I am very happy with the kit and it had additional rings that covered different models.

Martin....I got the Harbor kit a while back and most will work for the smooth bores with the exception of the fuel rails rings needing a little more thickness.... will probably just get these from Z1 when I get the other stuff needed or will check out the other places listed here.