Primary jets are larger than the secondary jets. Change the secondary jet when adjusting for altitude. Some carburetors may have different jet sizes on each side of the carburetor.
It is common for the jets to become frozen and hard to remove. Use a screw drive with a blade wide enough to cross the entire jet. Tapping on the top of the screw driver will sometimes loosen the jet. When the top of the jet has been damaged, use a brass drift punch an hit the punch so that the top of the jet slot is forced in a bit. This may give you enough metal for the screw driver to hold and at the same time loosen the jet.
| MAKE | YEAR | MODEL | CARB NUM | PRIMARY JET | SECONDARY JET | METERING ROD SIZE |
|---|---|---|---|---|---|---|
| MERCURY MARINE | MCM W/262″ 4.3LH 6CYL. | 9600S | .089 | .089 | na | |
| MERCURY MARINE | MCM W/262″ 4.3LX 6CYL. | 9600S | .089 | .089 | na | |
| MERCURY MARINE | MCM W/350 MAG 8CYL. | 9600S | .089 | .089 | na | |
| MERCURY MARINE | MCM 7.4L BRAVO I/II W/454 8CYL. | 9772S | .107 | .098 | na | |
| MERCURY MARINE | MCM W/350 MAG 8CYL. | 9772S | .107 | .098 | na | |
| MERCURY MARINE | MIE 8.2L W/502 8CYL. | 9772S | .107 | .098 | na | |
| MERCURY MARINE | MCM 7.4L BRAVO I/II W/454 8CYL. | 9773S | .107 | .107 | na | |
| MERCURY MARINE | MCM W/350 MAG 8CYL. | 9773S | .107 | .107 | na | |
| MERCURY MARINE | MIE 8.2L W/502 8CYL. | 9773S | .107 | .107 | na | |
| MERCURY MARINE | MCM W/262″ 4.3LH 6CYL. | 9776S | .110 | .101 | na | |
| MERCURY MARINE | MCM W/262″ 4.3LX 6CYL. | 9776S | .110 | .101 | na | |
| MERCURY MARINE | MCM W/350 MAG 8CYL. | 9776S | .110 | .101 | na | |
| MERCURY MARINE | MCM 7.4L BRAVO I/II W/454 8CYL. | 9780S | .104 | .098 | na | |
| MERCURY MARINE | MCM W/350 MAG 8CYL. | 9780S | .104 | .098 | na | |
| MERCURY MARINE | MIE 8.2L W/502 8CYL. | 9780S | .104 | .098 | na | |
| MERCURY MARINE | 1993-94 | V8 | 9600S | .089 | .089 | na |
| MERCURY MARINE | 1993-94 | V8 | 9776S | .110 | .101 | na |