Thunderbike Engineering

Fitting Instructions
Speedmaster/America - Thunderbike Sports Mufflers

Please Note: Read these instructions thoroughly before attempting to assemble.

You may require:
A gas welding torch, a small amount of black paint, a short narrow flat-blade screwdriver

Parts List:
  • L/H Muffler (1)
  • R/H Muffler (1)
  • M8 Stainless Plain Washers (4)
  • M8x 20 Stainless Bolts (4)
  1. Slacken 13mm front muffler clamp
  2. Remove 2x 12mm rear footrest mount plate bolts and remove plate. Rotate muffler and slide rearwards to remove. Note the position of the mounting rubbers and washers between the footrest plate and the muffler bracket
  3. REMOVAL OF SILENCER MOUNTING BRACKETS: Firstly undo the 4 Allen head bolts which fasten the mount to the silencer  if this results in the bolt turning but not releasing then see number 4.thru 5
  4. If you find the Allen bolts turn but will not release At this point you will need to use a gas-welding torch. If you are unfamiliar in the use of these, or do not have access to one, you will need to employ the services of a suitably equipped person competent in it’s use.

    Heat the 2x Allen bolt heads gently until glowing an orange colour, being careful not to melt the bolt head in any way. Keep them at this temperature for approx. 45-60 seconds. This is very important to allow the heavy-duty thread-locking agent applied by Triumph to release its hold.

    Allow the bolts to cool and remove them. If they are still stiff in any way, repeat the process.

  5. Paint the heat damaged area on bracket; this will only be small area and should be painted at this time.
  6. Refit bolts (Or the Stainless bolts supplied) to bracket first, then a plain washer to each bolt, and then tighten both.
  7. Fit original front clamp to the muffler and coat down-pipe and inside of muffler mating area with a suitable exhaust sealant or gasket silicone.
  8. Slide muffler into position and secure using the reverse of the removal process, taking care to ensure the correct fitment of the rubber mounts and washers at the footrest plate mount area.
  9. Repeat process on the other muffler.
  10. At this point, on carb models, we recommend adjusting the idle mixture screw. This can be done very easily with a short screwdriver. Note the original position of the screw then turn it anti-clockwise by one turn when viewed from underneath. The screw is located in the lower front area of the carburetor in the round extension which projects downwards, beside the electrical connections. ( Note on 2005 and later bikes a special tool is required to adjust the idle mixture screw)
  11. Start bike and idle to allow sealant to cure.
  12. Ride off into the distance with a big smile on your face.  Feel the power and enjoy the sound!!!
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