Weber 32/36 jetting
- Thread starter Nielsk
- Start date
BRENT in 10-uh-C
Well-known member
The Fiat engine appears to be about ½ the size of a Model-A ( 1600cc vs. 3300cc ). I doubt all the jetting in the world on that carburetor could make it work correctly.
bettlesr
Senior Member
When I Got mine the jets were as follows:
Primary Secondary
Idle 50 50
Main 135 135
Air 165 165
Pump 50 Blocked
I don't know what emulsion tube are in it. I would have to disassemble it to find out.
They also recommend using a low pressure fuel pump. I use a Carter rotary vane pump which puts out about 3 psi.
Hope this helps.
I am in the process of checking the mixture at different speed and loads to further correct them.
Dick
Primary Secondary
Idle 50 50
Main 135 135
Air 165 165
Pump 50 Blocked
I don't know what emulsion tube are in it. I would have to disassemble it to find out.
They also recommend using a low pressure fuel pump. I use a Carter rotary vane pump which puts out about 3 psi.
Hope this helps.
I am in the process of checking the mixture at different speed and loads to further correct them.
Dick
nkaminar
Well-known member
First, Bettlesr, post #3, is correct. The Weber sold for the A is the 32/36 model.
As far as jets are concerned, I experimented with a number of different size jets. Here is what worked best for me:
The transition jets are the little holes that come into play when the throttle is opened. The slightly larger sizes help with the transition from idle to the main jet. The #65 idle jet also helps with the transition. I don't think there is an idle jet for the 36 side as it is only opened once the 32 side is fully open (at least on my carburetor there isn't one).
Do not trust the numbers on the jets but measure them. The numbers are the diameter of the hole in hundreds of a mm. So a #150 jet is 1.50 mm diameter. I use a numbered drill set of small drill bits to measure the holes. I find a drill bit with the end opposite the cutting end that just fits into the hole and then measure the diameter of the bit with a micrometer. The numbered drills can be off too. You can buy precision pins that are the exact size but the numbered drill sets are far less expensive. I have drilled out jets to match the size stamped on them. If they are too big, try another jet or solder up the hole and then drill it out to the correct size.
There are many variables engine to engine, such as cam timing. What worked for me may not work for you. Don't be afraid to experiment. The jets are easy to change.
I am not sure how your carburetor is set up but my 32 side opens up all the way before the 36 side opens up (called progressive linkage). I do most of my driving with the 32 side and only open up the 36 side when I need an extra burst of power.
I have a Burtz engine with a 6.5 head.
As far as jets are concerned, I experimented with a number of different size jets. Here is what worked best for me:
- Idle jet #65 on 32 side.
- Main jet on 32 side is #145
- Main jet on 36 side is #150
- Float valve is #140 (I think)
- Drilled out transition jets to 0.028 and 0.038 inch.
- I did not touch any of the other jets.
The transition jets are the little holes that come into play when the throttle is opened. The slightly larger sizes help with the transition from idle to the main jet. The #65 idle jet also helps with the transition. I don't think there is an idle jet for the 36 side as it is only opened once the 32 side is fully open (at least on my carburetor there isn't one).
Do not trust the numbers on the jets but measure them. The numbers are the diameter of the hole in hundreds of a mm. So a #150 jet is 1.50 mm diameter. I use a numbered drill set of small drill bits to measure the holes. I find a drill bit with the end opposite the cutting end that just fits into the hole and then measure the diameter of the bit with a micrometer. The numbered drills can be off too. You can buy precision pins that are the exact size but the numbered drill sets are far less expensive. I have drilled out jets to match the size stamped on them. If they are too big, try another jet or solder up the hole and then drill it out to the correct size.
There are many variables engine to engine, such as cam timing. What worked for me may not work for you. Don't be afraid to experiment. The jets are easy to change.
I am not sure how your carburetor is set up but my 32 side opens up all the way before the 36 side opens up (called progressive linkage). I do most of my driving with the 32 side and only open up the 36 side when I need an extra burst of power.
I have a Burtz engine with a 6.5 head.
Last edited: