I understand the basic function of the carb except for the best way to set the economizer arm/valve. Still not sure what it is doing or where to set it (all the way open at idle?). Seems that valve isn't closed until near max RPM as I have it now. Also wondering what is the best place to set the butterfly in relation to the throttle arm.
Not sure my float is set high enough yet. Can't seem to richen the mixture enough on first try. Can adjust main jet down till stumbling from to lean, but open up high speed needle to find to rich, no can find.
Need some wisdom here from you all with "OF" experience please.
Would also be great if I could find a pdf file of the stromberg OF manual too. Didn't think that would be hard to find, but it has proved to be.
One place to look for some help in understanding the functions is OLD-CARBURETORS.COM then look at the 1927 Dyke's Carburetor Supplement. Start on Page 1236. THey talk about the Model O which is the general carburetor. Page through it and you'll find some good discussion on the economizer.
Hope this helps.
I don't know about a manual, but there's plenty of adjustment information on the forum!
It is very simple. Initial adjustment is as follows: Screw the idling jet (lower knob/screw)all the way in, then back out 1 turn. Screw the high speed idle jet (higher knob/screw)in all the way, then back out 2-1/2 turns. This will get the car started. After it warms up, with spark retarded half way,and the idle screw adjusted for desired rpms, turn idle screw/knob in for richer, out for leaner, until it hits a nice running spot for the idle.Then adjust throttle and speed up engine to driving rpms(about 1 inch on the quadrant), and adjust the high speed jet/knob. Turn the high speed jet knob/screw inwards/clockwise until engine starts to slow down,then back out until maximum speed mixture is reached, then back in 2 clicks. Basically play around with it from there, depending on how worn the carb is.
Two more comments I forgot above to those initially adjusting their OF's that is not in the manuals.
(1)You adjust the gas level in the float chamber by taking off the acorn nut on the float chamber cap. Under the acorn nut you will see the threaded top of the float needle and a smaller nut. By placing a tiny screwdriver at the top of the float needle you then run the smaller nut up or down the threads to adjust the gas level. The more threads you see above the nut the higher the gas level will be in the bowl when you let the needle move up and down on its own by the action of the floats. Be forwarned that the threads on the float needle may no longer fit tightly on the small nut and during operation and vibration the nut may eventually thread its way up the float needle and lower the gas level in the bowl until the engine stops from lack of gas. This happened to me 7 miles from home one time. I eventually adjusted the nut back to a good level and then applied one drop of loc-tite to the threads and the small nut has not moved now for two years.
(2) The "economizer" valve/needle can be adjusted by taking the tiny cotter pin from above the nut and screwing the nut up or down on the needle. I have mine set so the needle lifts up at any speed above a fast idle and find this makes sure there is no engine stumble between idle and pulling the throttle lever all the way down quickly. There is not only no stumble but an amazingly instant full throttle response on my '19 when I set the valve this way.
All of that is from this thread: http://www.mtfca.com/discus/messages/29/9381.html
Mike, thanks I will check that out.
Seth, thanks but I had already found that info and am past that point. I need to know what specifics I can look at now that it wont seem to richen with the approach you mentioned. Plus where to set the throttle arm/ramp in relation to the butterfly as it could be done favoring different ways.
Erich, I would suggest you contact Stan Howe. He did a magnificent job bringing my OF back inti serviceable condition, after test running it and setting it up.
Hope this helps.
Allan from down under.
Stan is the man. I was thinking I would not bug him, but it may be best after all. I nearly have it now after doing a little more research. Still waiting a time for a test drive.
Erich, I just posted a copy of the Stromberg OF Manual over at the MTFCI forum ( at a higher resolution then can be posted here) for you and anyone else that wants a copy. It can be copied and printed out at your end of the world.
I have the highest resolution scan of the manual on file as well that I can email to those interested.
Here's the link:
Jay when I open this I don't see a higher resolution. I tried to zoom into page 11, the air and fuel flow diagrams, it gets blurry. The file size is only 127k, at least that is what my machine says it is. This Forum allows 190K? Am I doing something wrong?
Mike, Looks like I uploaded the wrong sized photos on the MTFCI forum. Email me for the full size right off the scanner copy of the manual.