RotecTBIlogoMandatory AD: 2nd September 2010. Balancing Air Pressure. 

This Mandatory Advisory applies to all TBI’s purchased Prior to 1st of September 2010 and applies to all such units irrespective of performance achieved.

In tests conducted recently it was found that if conditions arise causing a differential in air pressure between intake air and at the location of the TBI then problems can arise.

A mandatory modification to the TBI is required.

Rectification can be achieved by taking one of the following paths:

  1. For the cost of freight for the round trip send the unit back to the factory and once modified it will be sent back to you. Cost $100 for freight but you must contact the factory for instructions and paperwork.
  2. You may wish to modify the TBI yourself using the following instructions.

Modification Procedure:

Materials required:

  1. 2 off grease nipples ¼” with 28 threads per inch
  2. 1 off 3/32” Aluminum flush rivet
  3. Length of tubing to attach to each modified grease nipple.


Steps Involved:

  • Using a 1/8” drill working from the top of the 2 grease nipples drill out the ball and spring in each.
  • Undo the 6xM5 socket head cap screws to separate the 2 parts that make up the regulator taking care not to damage the rubber diaphragm
  • Find the vent hole at the top part of the regulator and drill this hole out to 3/32”
  • Apply the 3/32” rivet to this hole to block the old vent hole.
  • Drill and tap a hole for the 1/4“ modified grease nipple with 28 tpi.
  • Screw the modified grease nipple to place
  • Turn the regulator cover over and grind/polish any protrusions flush to the surface. Ensure there are no burrs or sharp edges that may damage the rubber diaphragm
  • Re-assemble the regulator and reinstall it to the TBI.
  • At the intake air-box secure the other modified grease nipple
  • Run a piece of AIR BALLANCING hose between the 2 modified grease nipples.

Future regulators and TBI bodies will have the nipple already attached.

Current TBI's are equipped with nipples one on the regulator and at the air intake of the TBI.

Technical Support: Paul Chernikeeff.

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Document as a pdf


RotecTBIlogo AD: 15th March 2010

EXTRA NOTES: 15-03-2010 on the arrow to go back to the top menu back2top