Diaphram carbs

[gentlemanjim]

I recall as a kid with go karts they used a diaphram type carbureator and recently whil working on my daughters Polaris PWC I noticed that a 120 hp 3 cylinder two storke also has them. It seems they would be an easy and efficient retro fit to bikes. no float bowls, easily adjustable with external jet screws for low an high speed. What am I missing, if nothing my next bike build I'll get some these babies?

 

[Sundie]

Should work, given that you can match air/fuel that you need. IE: a carb that serves a similar (within 25%) displacement, it should be fairly simple to tune.

 

[gentlemanjim]

Has anyone had experience with them on a motorcycle? INXS you must have some drawings or pictures.

 

[gentlemanjim]

These are the little devils I'm taking about. The HR Series is good for up to 350cc's so a pair would take care of our needs. You can adjust the high speed needle with an externtal mixture screw - quick and easy.

 

[gggGary]

Not sure, they are (always?) found on 2 strokes? Seems like a can of worms unless you are doing something really trick on the bike.

 

[gentlemanjim]

That's a good point, maybe they only work on 2 strikes - I'm gonna check.

 

[inxs]

- mostly found on smaller 2 stroke motors, paragliders etc main producers tillotson, mikuni, walbro

 

[gentlemanjim]

INXS, can you think of any reason they would not work on 4 strokes?

 

[inxs]

- harleys used tillotson carbs i believe for a while-had problems with metering if i remember correctly-just going on memory here...today i think you can find them on snowmobiles used without accelerator pumps or any type of enricher circuit