Tech: Rebuilt Carburetor Install Guide

The carburetor can be easily replaced with a rebuilt one!

The 4 cylinder 2.6L Mitsubishi engine receives it's fuel from the Mikuni Carburetor. Last month, Richard Soloman detailed how to replace the secondary throttle actuator. When the carburetor finally wears out, some folks switch to an aftermarket unit, but for those who want to stick with OEM, and bring back the reliability of the stocker without worrying about extra vacuum lines, etc., Tad Sands offers some tips on installing your rebuilt Mikuni. (Ed.)

• 10mm open end
• 12mm socket
• Socket wrench
• Socket wrench extension
• Straight slot screwdriver
• Phillips head screwdriver
• Pliers

Above: The old carburetor after removal, and the engine, minus carb.

The first thing I did before I removed my old carb was to disconnect the battery. Then I removed the air hose, air cleaner assembly, air filter, and both the 12mm nut that is holding the air cleaner to the valve cover and the wing nut which is holding on the lid to the air cleaner. Once that is off you'll have a nice clear view of your carb and all of it's connecting hoses.

Before removing any of the vacuum, cooling, or fuel lines, I'd mark each one's original location. After you've got all the lines marked you can disconnect them. I drained a small amount of coolant from the cooling system so that the cooling hose didn't drain all over the place. Then take your 10mm open end wrench and remove the air cleaner stud from the old carb. Remove the securing pin from the automatic transmission (if so equipped) and then disconnnect the throttle cable from the carb. Disconnect the carb's electrical connection as well.

Now you'll need that 12mm socket and the wrench to remove the 4 bolts which secure the carb to the intake manifold. To break the carb free from the intake manifold just gently pull up on it. When the carb is finally removed clean the gasket surface on the intake manifold.

The new carburetor, before reassembly.

For the re-install take the new gasket and place it into position. Then gently lower the new carb into place (making sure that the gasket is still in place) and, using a criss-cross pattern, tighten down the 4 12mm bolts (being careful not to over-tighten them). Re-connect the throttle cable, electrical connection, automatic transmission securing pin, vacuum lines, cooling line, and the fuel lines. At this time you might want to purge the fuel pump or install a new fuel filter as well.

Once you get all of the carb's connections back where they belong you can re-install the air cleaner assembly and re-connect the battery. If you drained any coolant make sure that you put it back.

When you attempt to start your truck for the first time don't be suprised if it takes a few times before it actually fires. You may have to keep your foot on the gas to keep it running. Wait until the vehicle is totally warmed up before adjusting the idle speed. Most carbs are preset at the factory, but mine was way off for the idle and it just takes a phillips head screwdriver to adjust the idle speed. Thats about all there is to it and if you can't get the carb adjusted 100% perfect then I'd just take it to a local garage and have them do it, but congrats you've just installed a new carb on your Mitsubishi Montero/Raider!

*Note: You might have to keep your original throttle mounting plate.

This install was performed on an 87 Raider, but most steps apply to all years of the G54B 4cylinder (Ed.).