Air Box Removal Quick Guide

This procedure begins on page 5-62 of the service manual.

Tools and Supplies

Tools

• JIS cross-point screwdriver
  • A conventional Phillips screwdriver will work but is very likely to strip the heads of the screws holding the air box to the throttle bodies.
  • A suitable tool is provided as part of the pre-2006 tool kit. (Honda P/N 99003-10000, requires handle P/N 89103-538-000)
  • JIS Screwdriver sets are also available from Internet suppliers, craft and modelling shops. Most US based Auto-Parts stores have never heard of JIS.

Supplies

• Optional: Funnel retaining plates (Honda P/N 17254-MCS-305, quantity 4)
  • Honda recommends replacing these plates each time they are removed. This is usually not necessary; evaluate the condition of the tabs retaining the screw heads.

Disassembly

Raise the upper fuel tank. (See FuelTankQuickGuide)

Disconnect the IAT sensor cable from the air box.

Loosen, but do not remove, two screws at the front of the air box cover. JIS Cross-Point

Remove the remaining seven screws from the air box cover.

Remove the air box cover, taking care not to drop the two front screws that are still in the cover.

Remove the air filter.

• Store the filter with the open end up or oil will leak onto whatever surface it is placed.

For each of the funnels in the order of cylinders 1, 2, 3, 4:

• Mark the funnel to indicate which cylinder it matches. (A digital photo is a good help here, since the funnels are visibly different from each other)
• Bend back two tabs on the funnel retainer plate, exposing the screws.
• Remove two screws from the retainer plate.
• Remove the funnel and retainer plate as a single unit.
  • Note location of the arrows molded into the bottom of the funnel and their counterparts on the bottom of the air box.
• Remove two screws from the funnel base.
  • These screws strip very easily and tend to be very tight. Exercise care and restraint when removing them. If you encounter the slightest difficulty with a screwdriver, stop immediately and use an impact driver to break them loose.
• Remove the funnel base and store it with the funnel.

Lift the lower half of the air box from the throttle bodies.

Disconnect the PAIR hose from the rear.

Disconnect the crankcase breather hose from the front.

Procedure

None.

Reassembly

Connect the crankcase breather hose to the front.

Connect the PAIR hose to the rear.

Seat the lower half of the air box on the throttle bodies.

Install four funnel bases and eight screws.

• These screws strip very easily. Exercise care and restraint when installing them.
• Alternatively, look up any of the several modification suggestions, and replace these screws with Hex Head (Allen) screws

For each of the funnels in the order of cylinders 4, 3, 2, 1:

• Discard the funnel retainer plate and install a new one. (if needed)
• Install the funnel on the funnel base
  • Make sure the pointed protrusion on the base lines up with the arrow embossed in the floor of the air box.
• Install two screws holding the funnel and retainer plate to the base.
• Bend the tabs on the funnel retainer plate so they cover the screws and hold them in place.
• Correct funnel placement:
  

Install the air filter.

Install the air box cover after first placing the two front screws in their locations - easier to do before the cover is mounted.

Install, but do not tighten, the remaining seven air box cover screws.

Tighten nine air box cover screws in diagonally-opposite pairs.

Connect the IAT sensor cable to the air box.

Lower the upper fuel tank. (See FuelTankQuickGuide)

Post-Service Checkout

If the performance suffers, check that all items are securely installed and that there are no opportunities for unfiltered air to leak into the air box.

Related Information

Air box microfiche page: http://fiche.ronayers.com/Index.cfm/Module/Main/TypeID/26/Type/Motorcycle/MakeID/1/Make/Honda/YearID/45/Year/2004/ModelID/7497/Model/ST1300A/GroupID/329506/Group/AIR_CLEANER