Better atomisation of gas at the carb?

Brad William /

DAMN. Thought i was on to something. Looking into my carb while tuning and seeing the gas droplets bubbling off of the needle I wondered if it might be possible to atomize them better. I imagined a hollow tube replacing the tapered needle and with tiny holes drilled on the back side of it. I started looking for hollow tube of the right dimensions, put enough info into google to search for such a thing, and this video popped up. I'm definitely going to try this with an old junk carb lying around.

Re: Better atomisation of gas at the carb?

OG Crazy Wayne /

That's what I love about the little sha carburetors

Re: Better atomisation of gas at the carb?

Brad William /

> OG Crazy Wrote:

> -------------------------------------------------------

> That's what I love about the little sha carburetors

This is a feature of the SHA carbs?

Think about it, it seems like a fine idea. In place of the graduated taper, a series of holes is revealed as the needle rises. At half to full throttle the holes are delivering gas in a series of finer apertures than the conventional needle and higher up in the throat as well.

Re: Better atomisation of gas at the carb?

The SHA has no needle, just little holes. And it is a bitch to tune the lower ranges on larger jets.

Re: Better atomisation of gas at the carb?

Brad William /

Easiest way to quick experiment with this in a standard carb would be to drill ultra tiny holes in a brass tube from ACE hardware, cut to length, and jamb it into the seat where the jet needle usually slides in and out of the carb, so that it becomes a permanent part of the carb. Then drill out the round slide so it rides up and down on it with a close tolerance.

Of course it wont work! Of course it would be a nightmare to dial in! Of course it would probably be impossible to balance fuel efficiency with performance! All this is true. That's why it would be so cool to try! (edited)

Re: Better atomisation of gas at the carb?

OG Crazy Wayne /

> DPC Ryan Wrote:

> -------------------------------------------------------

> The SHA has no needle, just little holes. And it is a bitch to tune the

> lower ranges on larger jets.

nope they're easy peasy you either run a slide with more angle and or do two small V notches on the bottom of the slide just barely to either side of the atomizer tube on the slide.

To tune in the mid-range you use the stock mesh screen filter and just remove one or two screens to dial it in and they Rock with good mileage.

The secret is don't ditch the Sha screen filter are you will have nightmares trying to tune it in unless you patiently redrill atomizer holes slightly larger.

If you can't go 50 plus miles an hour on an 15 mm sha you're doing something wrong!

Yes the atomizer tube doesn't move up and down but the slide is right next to it and moves up and down creating a vacuum effect on the backside of the tube there for drawing the fuel into a fine mist of atomization.

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