fine tuning the Schebler HX

[DanM]

I've got the HX 181 running pretty good on my 26 JD.

What is the idea behind adjusting the spring tension with the center button?

Is this used to fix a poor transition between low/mid throttle that cannot be adjusted between the cam strip and the needle?

Some times it seems to run a little better if I set the "choke" out to the first step to increae the tension. This would imply screwing out the center buttonn to increase the tension on the air valve.

Any suggestions for smoothing out the transition from low, for example pulling awat from a stop, to a mid throttle. Runs ggreat below the 1/3 throttle, but am having some trouble smoothing iot out at 1/2. Seems rich, but doesbn't tension increase keep the valve closeed more=rich?

Any asdvice appreciated.

[Tommo]

Dan,
I send this instruction to anybody who asks me for the sort of info you want.
It comes out of a 1920's issue of Dykes Encylopedia and is about the best instructions on adjusting Model H's that I have found.
In answer to your question as to varying the air valve tension, Yes it does richen and weaken the mixture.
Tighter spring tension = richer mixture and visa versa.
Hope this helps.

[Tommo]

Prior to the Cannonball, Alan Travis sent me his Excelsior carb to overhaul and the attached are the instructions I sent back with the carb to him.
They differ a bit from the Dykes instructions but Alan thought they were easier than the others.
Nothing beats an ear and practice. Engine sounds will tell the experienced tuner if the motor is weak or rich, advanced or retarted, that the backfire is caused by a leaking exhaust and so on.
Happy tuning.

[exeric]

Thanks Peter. You are very generous with your knowledge and that is most appreciated. Scheblers can be rather mysterious.