Most tri-power systems we run into these days are not true tri-power carburetors. Most were put together by installing 3 2 jet carburetors that may, or may not look alike. The true tri-power setups consisted of 3 different carburetor numbers and the center carburetor was different from the two outboard carburetors. On a tri-power system, the 2 outboard carburetors did not use idle mixture screws. There is no idle system on the outboards and if, by chance you do have idle mixture screws, turn them in all the way to cut off the air/fuel.
Tri-power can use a vacuum type linkage, or a progressive linkage. You will most likely have an after market progressive linkage. This means that the throttle in the center carburetor will be opened 1st, then as the throttle is pressed down, the outside carburetor throttles are opened. Be sure the linkage is adjusted correctly, or the outboard throttle valves may be opening too soon causing a fast idle situation.
The center carburetor would have an integral (mounted on the carburetor) choke mounted. The 2 outer carburetors would not have a choke. We do have electric chokes available but there were several variations of chokes on the 2 jets, so be careful picking out the correct choke.
To get your tri-power system to work correctly you will need:
- Engine modified to tri-power specifications.
- The 3 carburetors should be re-built at the same time by someone that knows about tri-power carburetors. (not easy). They would need to know that the carburetors are jetted differently and the 3 carburetors don't have the same parts inside.
- Correct linkage installed and adjusted correctly.
Buying carburetor kits based on the idea that you have a tru tri-power setup with matching numbers will probably get you the wrong kits. You can only be sure when the carburetors still have the original ID tags attached to the top. Without the tags, you should match up the old parts with what is in the carburetor kits.
Here is an example of original Chevrolet tri-power carburetors.
| YEAR | MODEL | CARBURETOR NUMBER |
|---|---|---|
| 1959-61 | CENTER A/T TRI POWER | 7013016 |
| 1959-61 | CENTER S/T | 7013020 |
| 1959-61 | CENTER A/T AIR TRI POWER | 7013026 |
| 1959-61 | CENTER TRI POWER | 7013974 |
| 1959-61 | FRONT TRI POWER | 7013015 |
| 1959-61 | REAR TRI POWER | 7013017 |
| 1959-61 | FRONT TRI POWER | 7013973 |
| 1959-61 | REAR TRI POWER | 7013975 |
1958 Chevrolet Tri-Power Setup
1958 Oldsmobile Tri-Power Set Up
1958 Pontiac Tri-Power Setup
