>>> > I have decided to make a simple carb for those people that >>> > don't want to deal with EFI. It is a real shame that one needs >>> > a degree in electrical engineering to tune and install current >>> EFI > products. >>> > Anybody can understand a carb. The leaning system uses an >>> eccentric > shaft >>> > just like the rotary to change the float level. Super simple. >>> > >>> > I stole an idea from Weber carbs. There will be two small

venturis

>>> > that do the fuel metering. Can't beat a simple system like

that.

>>> > Internal fuel passages are not shown yet for the most part. >>> > >>> > Hopefully Larry will build it and sell it. I am sure he will

have

>>> > a lot of suggestions for improvements. >>> > >>> > This carb works with Doc's slide throttle as is. It is merely

bolted

>>> > to the side of the slide throttle. >>> > >>> > This is a low technical risk solution. Guaranteed to work right >>> > out of the box. No innovation here. >>> > >>> > Paul Lamar ...No rotor no motor. >>> >>> Excellent idea. Add a simple crank trigger ignition. Forget the >>> computer. Jerry >> >> It is too late for me, but I like it. >> Buly >> >> Your decision has convinced me it is the way to go. >> >> Here is what the outside looks like. Hey you should have asked me

for

>> help >> on the wiring. I would have made you a whole new wiring harness

for free

>> and flown down there and installed it for you :) > > > Paul Lamar > > > Paul, > Why not copy a Tillotsen diaphragm carb from the old days of

go-kart

> racing. Then you would not have the bowl full of fuel and the

delicate

> float mechanism to worry about. Your mixture cam could bear on a

spring

> against the diaphragm. Using the diaphragm as a regulator, I think

you

> could meter fuel directly into the slide throttle. Think about the > Bendix pressure injection carbs. > > Aubrey Thompson > > That is an interesting idea Aubrey. Thanks for the tip. I am

looking

> into it. > Here is a very good site on the subject. > http://www.aerocorsair.com/id27.htm
Paul, Here is a diagram of the fuel flow through the small, HU series carb that does not have the fuel pump diaphragm.
Aubrey Thompson
Yes that is a much better illustration of how it works. It is also a

good

illustration of why you don't want butterfly valves in an aircraft

engine

that runs wide open throttle 99% of the time.
I wonder if that simple main adjustment needle valve will do the job

of leaning.

I suspect the other needle is an idle mixture adjustment. Probably

not needed

in a rotary that idles at 2000 RPM.
Thanks for suggesting this Aubrey. I am liking it more and more. Super simple and super compact.
Paul Lamar ...No rotor no motor.

I believe that type of carb is what is used on jetski /waverunner/watercraft. Mikuni brand, BM series. see: http://www.parkeryamaha.com/index.asp?PageAction=VIEWCATS&Category=333 http://www.parkeryamaha.com/index.asp?PageAction=VIEWPROD&ProdID=18207 Detailed Description High performance carburetors with extended throttle throttle shaft.
Features a high performance tip needle valve to provide optimum pop-off and a
primer type cold start system ( no butterfly choke) to increase air flow. Carb Spec's. Low Speed 120. High Speed 150. Needle Valve 2.5. Spring Grams
80. Primer kit required.
bunch of stock smaller ones on ebay
see ebay item #s:
120147388486 and 170136272480 and 260144907037
as an aside question I have been wondering about using a vacuum driven/ mechanical fuel pump as used on may snow machines and jest skis. some
put out up to 35 liters per HAR. like so: http://www.parkeryamaha.com/index.asp?PageAction=VIEWPROD&ProdID=24324
Michael Silvius
Mikunis work differently. We have looked at those and the principle is not as easy to implement. They having moving needles
valves that are hard to implement with our p-port spacing. We have looked at
lot of possible configurations over the years and the Tillotson is the best
I have seen so far. Easy to make and cheap. There is no beating a venturi for
simplicity.
Paul,
The Mikuni in the link is a different carb than the standard Mikuni.
The Jet ski carb works like the Tillotson.
Bill Jepson



The Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://www.rotaryeng.net
Copyright 1998-2006 All world wide rights reserved.