>>Noah writes...
>>
>> Help. I am having the toughest time getting the carbureters on my '74
>>Midget in tune. 2 days back, I decided to take the carbs off of Smidgie and
>>give them a thorough cleaning/examination. Well, the throttle spindle and
>>valve were well worn so I replaces them with much less worn ones from a spare
>>carb that came off of a 67 Sprite. Also cleaned out the muck from the bottom
>>of the float chambers and double checked that everything was up to snuff.
>>After making sure that everything was a-ok, I decided that today was the day
>to
>>refit those archaic babys. They slapped on no problem, gave the engine a
>turn
>>and vroom vroom, a lovely choke and sputter that sounded nothing like the
>>putputput from before.
In cleaning and examining the carbs, I'm sure that you changed the rich lean
setting. What about the float bowl hieght? Even if you didn't move the jet,
the
float bowl setting might be so high that its rich no matter what the setting of
the jet.
>> Damn I thought, I guess the carbs are out of tune. I spent a good
>>four hours trying to tune up the car, using a Hayes manual but the state of
>>tunage only got a bit better. The car idles semi-smoothly with puffs of black
>>smoke comming from the tail pipe. When driven under load (above 2500 or so)
>>the car backfires like a son of a gun and sputters and generally drives like
>#
>>$#%@! Ah yes, the backfiring also happens at idle, but not all that
>>frequently.
Here is what I would suggest. Its all work you can do with the carbs in on the
engine.
1. Take the tops of the float bowls. Turn the tops over and check to
see
that the floats measure 1/8 inch higher thanthe top of the inner rim
of the bowl lid.
2. Take the piston assembly off the carb. Turn the mixture nut
clockwise
until the jet is even with the top of the bridge. Now, turn the
mixture nut counter clockwise 12 flats. This is an initial setting
where the car should start and run. Replace the piston/dashpot
cover.
3. Fill dashpot with appropriate amount of engine oil.
Now, start the car. It should start. You can then follow the instructions for
setting the rich lean as outlined in the Haynes manual. If you need the
instructions, I can type them in. Since they should be in there, I'll save my
fingers. REMEMBER, however, the car must be warm for those instructions to
work.
Let the temp gauge get the normal operating spot for your particular car, then
sit in it for 30 seconds and press on the accellerator so it turns at about 2000
RPM. This will ensure that its warm enough.
The rich lean mixture probably won't have you going more than 4 flats in either
direction. If it does, be sure you're following the directions to the letter.
>>I checked the timing/distributor/plugs etc. and all were fine. The car was
>>driving nicely before the cleaning (yes I know... stupid idea to mess with
>>anything that is working) so I am assuming that the problem lies in the carb.
>>From the smoke, I am also assuming that the carb is running rich, but when I
>>try to adjust the mixture, the smoke sticks around even when the jets are all
>>the way up. Well, I'm hoping someone out there in net-land has any
>suggestions
>>for a not so bright but well meaning british car lover who just couldn't keep
>>his mits off of something that I was almost satisfied with.
VERY rich.
Good Luck!
-Al
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