RS EHO35: What is this adjustment screw on carb?

Mike St

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I ordered this replacement carb for my RS35 and see there is an adjustment
screw which is not on the original carb. The screw is just above the fuel
inlet tube, and you can see it in this pic: What is it for?
Look at the fifth pic to the right. I suspect it is a fuel/air adjustment
screw since it is located directly above the fuel inlet tube.
Here's a better pic of this screw:
 

darwin

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I see a big brass screw and a small black screw going into the side of the black separation plate[?]. Brass one might be an air mixture jet.
 

Mike St

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I confirmed that it is an air-mixture screw by going the the RSeho35 service
manual and looking at a diagram of the carburetor, and there it was.
Apparently, Robin changed the design to include this screw on later
models, and I have an older carb/ engine that just has an idle
adjustment. I will install the new carb.

I see there's also an adjustment brass screw on top of the throttle
which is not on the original carb. This could be to adjust the position
of the throttle. Maybe it can act like a governor. Not sure what it is.
It's shown in the 4th pic above.
 

Sidewinder Jerry

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I ordered this replacement carb for my RS35 and see there is an adjustment
screw which is not on the original carb. The screw is just above the fuel
inlet tube, and you can see it in this pic: What is it for?
Look at the fifth pic to the right. I suspect it is a fuel/air adjustment
screw since it is located directly above the fuel inlet tube.
Here's a better pic of this screw:
That's your high adjustment screw. With the throttle wide open and your engine drive chain off adjust it to where the tachometer reads it's highest no load rpm and leave the screw there. The next adjust screw is the low adjustment screw where you adjust to the highest rpm with no throttle then turn it back to where the rpm just drops favoring the rich side and leave it there. Last of all adjust the idle screw to 3000 rpm.

Here's a thread where I explain all of this. In the picture where I'm showing you the low adjustment screw it's under the black rubber plug in the center.

 

Mike St

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Yes, yes, yes, I will read it all carefully. I'm on to
see the wizard of OZ! My new carb looks just like
that.
 
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