Mixture screw rubber o rings

Hi, I have my 1979 Z13 carbs apart for some ultrasonic cleaning. The mixture screws were really loose in the holes due to worn out o rings. Does anybody know where I can get these? Cheers Marc.

Everyone knows or should know that I have been pushing information regarding Ethanol blended gasoline and the effect it has on elastomers (rubber based components) All the carb kits available for the KZ1300 have Buna N Nitrile o-rings and those o-rings hate ethanol. You need to buy Viton 75 material based orings to work with the ethanol. They are more expensive than the Buna N o-rings but if $10.00 for a complete set of o-rings to rebuild 3 carbs is going to break the bank then sell the beast.
www.theoringstore.com will sell you a set of o-rings including shipping for around the $10 mark. This is what you need

[/Oring for the Neeedle Seat Body 7.5mm X 1.5mm $1.39 each
Oring for Idle Air Needle 3.0mm X 1.5mm $0.75 each
Oring for carb bowl drain screw is a part #007 since there was no metric equivalent that fit correctly. cost $1.05
1980 KZ1300 B2 converting to an A2.
Now all that being said, you can get away with Buna-N o-rings for the air screws since they are not exposed to the fuel. I would think there is an oring store in your area and now you have the sizes required for the o-rings in the carbs. This info is also in the FAQ section of the site.
Hope this helps.
KB

You sir, are a diamond. Thanks. I know the fuel eats these things but, this bike also hasn’t turned a wheel in eleven years and the whole thing turns forty this year. A lot of the rubber bits are giving me a headache.

Actually; the o-rings on the mixture screws (6) never come in contact with fuel. The idle-jets are under venturi vacuum which draws the fuel/air mix (only) past the needle tip. The o-rings prevent (additional unmetered) air from being drawn down past the threads which would create an idle issue.

Kawboy wrote:

Oring for the Neeedle Seat Body 7.5mm X 1.5mm $1.39 each
Oring for Idle Air Needle 3.0mm X 1.5mm $0.75 each
Oring for carb bowl drain screw is a part #007 since there was no metric equivalent that fit correctly. cost $1.05

I just contacted the www.theoringstore.com customer service asking which exactly Viton 75 rings they suggest for ethanol containing fuels. They came back with V75 FKM (Viton, Fluorocarbon) 75 Duro O-Rings. (there are other types)

I'm just wondering about the prices you quoted Kawboy - they seem very high marked 'each'. Perhaps you meant per each bunch?

Anyway. The respective prices are $0.16, $0.14 and $0.04 per each o-ring. There is a minimum quantity to order - 4. I think it makes sense to order double the number needed for one carb and have spares, just in case. I'll be ordering more than that as I need to take care of more carbs than one.

Those prices I quoted were what I paid at an o-ring supplier in Newmarket Ontario. Later I found the oringstore.com . Better prices for sure.