Topic: CB400 Carburetor O-Rings

[grumpy56]

Carb O-Rings - Does anyone know the size of the O-rings used on the fuel interconnects between the carbs and also the fuel line connector between carbs 2 and 3? Are they standard or do I need to locate the "Honda Gasket Sets"? Thanks.

[bryanj]

Ask Nurse Julie a member on here, she sells viton O ring kits for carbs and oil pumps

[Kenzo1979]

Pretty sure they are 5.8mm x 1.9mm.  Just order some in Viton.  I’m seeing packs of 10 from a bunch of places, even Walmart.

[grumpy56]

Thank you all.

[Deltarider]

Carb O-Rings - Does anyone know the size of the O-rings used on the fuel interconnects between the carbs and also the fuel line connector between carbs 2 and 3? Are they standard or do I need to locate the "Honda Gasket Sets"? Thanks.

Do they leak? Realise that after a long period of sitting, they shrink. First step would be to open the petcock and... wait. Usually they swell up again to their original dimensions.

[grumpy56]

Not sure if they leaked. Have not been used in 10+ years. Wanted to avoid having to rip them apart again if they do leak upon assembly.

[Tim2005]

8 x 2mm I think. But, they rarely leak. As your carbs have been empty so long then before installing them and while you have them on the workbench fill them with gas and let them stand a day or 2, you can keep an eye for any leaks and deal with them then, it's much easier than fitting & removing them and it saves any new engine paint getting spoiled

[Deltarider]

Not sure if they leaked. Have not been used in 10+ years. Wanted to avoid having to rip them apart again if they do leak upon assembly.

Why did you rip them apart in the first place?

[grumpy56]

One carb of the set had a broken float post and another had a main jet post/nozzle that was falling apart. I actually pieced together a full set that is now on bike and this set will be a spare or will sell it.