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Discussion Starter · #1 ·
Hi all,

I have a Weber 32/36 and I live at altitude 5050 msl. It has a slight stumble from idle. I tried like an idiot to cut a link off the power pump but that was the wrong thing to do. Didn't help. So I put a stock one back in. I'm thinking I should maybe try different jetting??? What do you think I should try. I pulled out the jets to see what I have in there. See picture.
436310
 

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Those in aviation will tell you with a carbureted motor the higher you go the more you lean it out. If you go into the search mode here you should find some post's by Otto Bartsch " tekenaar" on jetting the weber 32/36 for a stock 1.9L engine. I would start with his numbers and then go a bit leaner. I think I ended up with main 135/150 idle 50, sec 140/165 idle 55.
 

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MODERATOR'S NOTE:

I moved this to the Aftermarket Down-draft carbs Forum. There are DOZENS of excellent threads about jetting Weber carbs. I would strongly advise you read them



Fuel jets that have a larger number are larger, and allow more fuel through, so a larger fuel jet makes the mixture richer.

Air correctors (I think what is referred to above to as "sec"), on the other hand, are the jet-looking things above the emulsion tubes, and allow air to enter and mix in the emulsion tubes with the fuel that passed through the main fuel jet. So a larger air corrector makes the mixture leaner. But not in the same ratio as the main jet. Each change of an air corrector is roughly equivalent to a one-third change in a main jet. A "10" fuel jet increase is equivalent to a "30" decrease in the air corrector size. And vice versa.

Which side is the Primary side and Secondary side in the diagram I posted?
In diagram above, if it is a DGAV / DGEV / DGAS / DGES (NOT if it is a Weber DF or Holley Weber), the primary is on the left (outboard) and the secondary is on the right (inboard).

The jetting as shown in the diagram is:

Primary:
Idle: Not Specified
Main: 140
Air Corrector: 170

Secondary:
Idle: Not Specified
Main: 140
Air Corrector: 160

Happy reading and good luck!
 

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Left side of diagram is primary. Don’t leave out the idle jets, you may want to step down to a 50 or 55 on the primary side. If you’re above 5,000’ also step up your air correctors in relation to your mains.
Example:
Idle P Main P Air P Idle S Main S Air S
55 135 185 50 135 175
The idle jets have a fixed bore for the air correctors, all you can do is try stepping down on the idle jet size.
If you live above 5,000’ a step down on the mains might be worth a try along with using the larger air correctors. You’ll have to experiment a little bit I wouldn’t waste my money on that high altitude jet kit you won’t need most of those jets. Get a 50 & 55 idle jet, a 130, a couple of 135 main jets and a handful of the air correctors 175, 180, 185, 190’s. With what you have that should put you in good shape.

I’ve purchased a bulk quantity directly from Redline for $3.25 per jet over the phone. Carburation.com is another good source for jets . Lots of good threads were just bumped up on the forum, it’s just trial and error finding the right combination
 

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As I recall, the rule of thumb with altitude is that there is roughly 4% less oxygen per 1000 ft above sea level.

At 5000 ft, you are dealing with 20% less oxygen than at sea level. Proportionately smaller fuel jets might be a good starting point.
 

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Discussion Starter · #8 ·
After trying a couple different configurations here is what seems to work. No stumble so far. I'll drive it for a while and see.
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