TOPIC:

asphalt900 wrote: ... I o-ring the bowls of the mikuni VM's ...

How do you O-ring the rounded-square VM28 bodies/bowls and seal around the starter jet well at the same time? Pics of examples, please?

Good Ridin'
slmjim & Z1BEBE

Easy peezy, here are some from a set of Early KZ1000 carbs and a Z. Just follow the casting bump imprint left on the old gasket as a templet for positioning of o-ring. Bowl surface has to be CLEAN for the superglue to stick. O-ring does not compromise the height of overflow tube and choke hole doesn't really have to be fully covered. The choke has it's "air correction" built into roof of carb body. I cut at a 45deg. on the mating points of o-ring.

Oh forgot to mention. Where Keihin DID use a flat rubber float bowl gasket this trick is even easier because of the lack of choke enrichners, choke plates used instead. CB160's benefit from this "pinch point" of an o-ring because the carbs are canted forward. CB450 and numerous others. Flat on flat on flat doesn't seal very well.

Ness here is an example on a completed set of the earliest ribless carbs with all the mods I have mentioned. Fuel tees, o-ringed bowls, professionally re-plated metal bits(not some Eastwood/Caswell or homebrew kit), etc. etc. etc. I trust in what I do ONLY because it has proven it's self over and over and over again. I know first attempts at anything can/will require re-thinking, back to the drawing board kinda thing, these concepts Work.

Asphalt, how do you control o-ring crush on the float bowl without a groove on the bowl?

I was waiting for that Question!!! By feel. You "should" be using screws with split keepers, A lot of what I see are persons using allen head ss screws, super bad idea. In addition the threads of the cheap M4 screws are cut not roll formed. Using the allens screws gives you a torque advantage that was never intended, plus "my opinion" it makes them look crappy. The split keeper on a captured panhead JIS phillips keeps them from backing out. Too many people Ham-Fist the screws under the assumption that the harder they torque the better seal they will get, Wrong Wrong Wrong. This is the reason a lot of the carb castings are bowed today.

asphalt900 wrote: I was waiting for that Question!!! By feel. You "should" be using screws with split keepers, A lot of what I see are persons using allen head ss screws, super bad idea. In addition the threads of the cheap M4 screws are cut not roll formed. Using the allens screws gives you a torque advantage that was never intended, plus "my opinion" it makes them look crappy. The split keeper on a captured panhead JIS phillips keeps them from backing out. Too many people Ham-Fist the screws under the assumption that the harder they torque the better seal they will get, Wrong Wrong Wrong. This is the reason a lot of the carb castings are bowed today.

The Keihin carbs use an O-ring channel and one piece O-ring. You tighten up the float bowl screws until the float bowl bottoms against the carb, and the O-ring is captured in the groove providing the seal. With your approach there is nothing keeping the O-ring from squirming out of position, plus the split in your O-ring can open up. Sorry man, but BAD idea.

Here are photos of a couple sets of carbs I restored. I replate the hardware myself and glass bead blast the bodies.

I understand your concerns. That's why this is called a forum. But I have been doing the exact same thing for over 10yrs???

Just a quick Q. How do you yellow chromate at your house?

My point of view is related to my experience as a quality engineer working for a major automotive OEM, including 8 years at an assembly plant. I've seen multiple times where a single piece of hair or fiber from a cloth glove was laying across a fuel system O-ring causing a leak path. Of course a car's fuel system is under pressure but still. I don't like messing with gas.

asphalt900 wrote: Just a quick Q. How do you yellow chromate at your house?

I've got a Caswell's kit and they sell various chromate dips. Blue is for silver parts, yellow, and a black. The yellow/black coloring isn't super durable against abrasion, but the plating itself is pretty good if you prep the metal well.

You are absolutely correct about problems occurring at any level, these are machines, they are infallible. The opinions I express are just that, my experiences. We will leave it at that, OK. Not here to compete, just share. Good luck with Your sales!! Clay