.: How to install the Adjustable Leak Jet :.


ALJ - Adjustable Leak Jet
ALJ Info | Buy the ALJ

* Important - If you are not a competent mechanic do not attempt to install this kit yourself, please have your local dealer install it for you.

 

Launch in external player

Get Windows Media Player

 

Precautions:

  • Always wear Safety Glasses when working on a motorcycle.
  • Always let the motorcycle cool down completely before you work on the fuel system.
  • Gasoline is flammable! Read all safety instructions in your manual.
  • Always clean the area around the carburetor before disassembly.
    • Remove the float bowl per the service manual for your motorcycle. Tip: You may be able to remove the bowl by loosening the clamps and rotating the carb body. Some motorcycles will require the carb to be completely removed to access the float bowl screws. Also, make a note of the overflow hose routing so you can reassemble correctly.
    • With the float bowl on a work bench remove the 3 diaphragm cover screws.
    • Turn the bowl over and remove the leak jet (Some carb versions like early Yamaha and KTM models do not have a leak jet) .
    • If you removed a leak jet you need to install the leak jet plug supplied. See Fig 1
    • Secure the supplied drill fixture to the float bowl with 2 of the original diaphragm cover screws . Important - please note the position and orientation of the fixture. See Fig 2
    • Drill a hole through the float bowl with the 2mm bit supplied. Drill the hole straight and aligned with the pilot hole in the fixture – It is advisable to use a bench drill to carry out this procedure.
    • Remove the fixture and check to see if there are any burrs or metal fragments on the inside of the bowl. If so, remove them.
    • You will notice that the Merge diaphragm cover has a check valve located in the bottom. See Fig 3 If your original diaphragm cover does not have a check valve like this it is located in the float bowl and must be removed. Drive out the ball, spring and plug using a small punch or the shank end of the drill bit from this kit, See Fig 4 .
    • Thoroughly clean the float bowl.
    • Assemble the diaphragm, diaphragm spring and Merge cover on to the float bowl. (Tip – refer to your owner’s manual to assemble the spring and diaphragm correctly.)
    • Replace the 3 screws that hold the cover in place and tighten.
    • Assemble the float bowl on the carburetor per your users manual.
    • If you have removed the carb from the motorcycle replace it at this time. Then tighten all screws and clamps.

Adjustment and Setup

Note: From this point forward we will refer to the Air/Fuel mixture as A/F mixture. Also, we will only refer to tuning parts that are readily available and can subsequently be replaced.

Before you attempt to make adjustments make sure your engine is serviced. Piston, Rings, Valve clearances and the air filter etc are extremely important.

  • Fuel Screw - The fuel screw works in direct conjunction with the pilot jet. The engine will run its best in 1 to 2 turn range and at normal operating temperature if you have correct pilot jet. If it runs better less than 1 turn, the pilot is too big. If it runs better more then 2 1/2 it needs a larger pilot. To adjust the fuel screw, set it at 1½ turns and then get the engine up to operating temperature. Next slowly turn the screw in until the engine starts to slow down and then back it off 1/8 of a turn. The screw should be in the 1 to 2 turns range. If not change the pilot.
  • Idle – with the engine at operating temperature run the idle as low as possible without stalling. Idle speed is a matter of preference, but if it’s too low, the motorcycle will be harder to start, especially when the engine is hot.
  • ALJ Screw – The adjustable leak screw is normally set at 1 turn out; test your setting by adjusting the screw in ¼ turn at a time. The engine will be noticeably rich when it’s too far in, and you open and close the throttle rapidly. From this point back off 1/8 of a turn for maximum fuel. You can back off further to create more traction on slippery tracks.

Jetting for Performance

130 applications have been logged at the time of introduction. However, hundreds of fuel, aftermarket tuning options and climatic variations make it impossible to give exact jetting specifications. We will however post updates for specific models and tuning tips on our web site.