What to do first

B

buddyholley19

Member
Hope this is not a silly question. I want to set my timing and adjust my carb idle. What would you do first. The car runs pretty good .Starts great new rebuilt carb last year (from berts) No big issues. I do know I'm idling a little fast. Im having some issues double clutching when I gear down from 3 to 2.I have changed the 600w oil in the ******. still learning thanks in advance .
 
I would adjust the timing first, then adjust the idle mixture screw and then the idle speed itself. As for downshifting from 3rd to 2nd, there is a big difference in the gear ratios, so depending on how fast you are going, you have to really blip the throttle after you shift from 3rd to neutral. Once you figure the right amount of throttle to use, it is quite easy.....but if you use too little or too much, it will grind.
 
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You say the car "starts great" and runs "pretty good". Leave the timing alone, just lower the idle speed. Practice double-clutching on the downshift.
Good Luck:)
 
The initial timing procedure for an A is just to have the spark occur at top dead center (or slightly after) while starting, to avoid it kicking back if you are hand cranking. Once the engine starts you pull the spark lever down to your preferred position, thereby advancing the timing from the initial setting. So a Model A's actual timing is controlled by the spark lever, not the initial setting! There's no need to obsess over getting that initial setting down to a gnat's eyelash because it changes as soon as you move the lever. So what if the initial setting is like two or three degrees off! That 'sweet spot' you like to run at is still there, just a click or two up or down of the lever.
 
Turn the screw on the throttle plate until you get the lowest reliable idle you can. Screw in the idle air mixture screw in until the engine starts to stumble and wants to stall. Now back out the screw counting the number of turns until the engine starts to stumble and wants to stall. Screw it back in 1/2 the number of turns you counted.

It takes longer to read this then to do it.
 
If you want to check the timing, set the points first to .020". If the engine speed is low and slow with the lever up, engine speed increases with lever 1/2-2/3 down, and then rolls when fully down. I'd say timing is alright.

Generally the idle speed can effect upshifts. Idle should be nice and slow but not too slow.

Downshifting takes some practice. I'll assume you're trying to double clutch as you should. Usually the problem comes from not raising the engine speed enough at first.

But the things to do if wanted is first to last
set points
check/set timing
set idle speed
adjust idle mixture
reset idle speed if necessary
 
Before you check the timing you need to check the point gap ----the timing should stay correct for a long time, just the point gap needs checked ---then do any carb adjustments you want to do
 
As far as down shifting goes:
First, a fast idle will make smooth shifting more difficult so reduce it.
Second, the biggest tip I can give is to slow down and take your time! The model A has plenty of inertia and will continue to coast while you shift. So shift from 3rd to neutral. Clutch out. Blip the throttle. Clutch in. The slowly ease into 2nd. If you experience any grinding back to neutral and clutch out. Now try again - slowly. you will soon find the sweet spot of speed and RPM where smooth shifting happens. Finally practice on level ground. If you try going up hill you will slow down more quickly and feel the need to get it into 2nd quickly - before it is too late! Once you have mastered the down shift then you can tackle the hill.

One final comment about driving my Model A. Way back in the 1960s when I was taking flying lessons (I was 14), my instructor would stress staying "ahead" of the situation in the aircraft (at that time a Piper Colt - sort of a fabric covered fly brick!). Much the same holds true when driving my A.

In a modern car with power brakes, steering, and automatic transmission you don't have as great need to plan ahead. In my A every stop, turn, and traffic interaction is anticipated and planned.
 

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