My 1930 Ford is completely stock except the distributor has been changed to "pointless" and it has a high speed rearend. I have never managed to get the car over 38 MPH, it should hit mid to upper 40's. The car also uses a lot of fuel. I checked the timing and according to the manual I have the timing was advanced quite a bit so I re-set the timing per the manual. I also attempted to set the air/fuel screw according to the manual. Per the manual clockwise rotation of the screw should cause the car to begin to stall. The screw is then turned CCW until the car begins to stall. Midway between these positions is the correct adjustment. The car did not begin to stall at any point of the adjustment. Again according to the manual this indicates an air leak somewhere on the carb. I tested all bolts and nuts and they were properly torqued. Now, I can't get the car over 25 MPH and the fuel mixture must be set very rich to prevent backfiring.

First, carb adjustments only tune idle speeds. Turning clockwise shuts the gas off. When backing off, leave it at the point where your engine runs smoothly. Backing off any more, will make the mixture richer.

Backfire means your timing is too advanced. That usually raises the coolant temp, too. Start by putting your timing at 6-8 degrees before top dead center.

Having a vacuum leak will throw everything off, so seriously check for leaks. It could leak anywhere. If you have vacuum wipers, check under your dash and under the hood. Also check under the carb, or where the intake manifold attaches to the head. Sometimes I check leaks using UN-lit propane. If the propane gets sucked in, your engine will increase idle speed.

My stock 1929 Model A Phaeton with the original stock rear end easily goes 55 miles per hour. With a tailwind or a slight downgrade, it will go 60 miles per hour. You need to get back to basics. A Model A is not difficult to work on. Compression, Fuel, and Spark (with a few simple adjustments), and it should run much better than you are describing.

I am not enough of an expert to talk you through this and all of my manuals are out in the garage. What service manuals do you have available?

You might also check out the technical section of the MAFCA Website at this link:

http://www.mafca.com/06TECH.html

On your carb, are you adjusting the know on the right hand side of the dash or the IDLE mixture screw on the carb?

The knob on the dash should be turned clockwise ALL THE WAY IN (but don't force it) and then opened no more than 1/2 turn in most situations

Bill

One thing often overlooked is clogged exhaust. disconnect the exhaust pipoe and run it and see if any difference. It will be noisey but will tell you if that is the problem

have you pulled the timing pin on the front of the motor and started from scratch on the timing before adjusting the distributor?? I'd start there 1st then work my way to the carb, then to the exhaust...that way you are not "hen pecking" to try and find a problem. I like to start at 1 area at a time and when I know that that certain area is set properly I move on. There isnt too much to these little engines. Take your time, we have all gone through what you are doing...after youget it figured out, she'll run like a top.

My 26 Chevy did the same thing. No power and sucked gas. Turned out the inside of the carb was messed up. You wouldn't know it by the way it idled or as smoothly as it ran going down the road though.