Retro Kit for Intake Tubes on Monster 05.11.2003

Application: At All Monster Engines
Reason for retrofit kit: Better mixture control at any speed

Hirth provides a rubber fixing flange for the carburetor as a standard which unfortunaly does not work: It cracks after a short time. We added rubber joints to support the carburetor weight. But due to vibrations the fuel in the floatbowl gets mixed up with air at certain speeds. This makes a precise carburetted air control very difficult, especially as the vibrations depend on the weather and temperature conditions.

Meanwhile Fresh Breeze developed a new carburetor suspension system, which is now soft enough to prevent the gas from frothing up. We offer it as a retrofit kit.

The kit consists of a piece wire-reinforced PVC-tube, special clamps and a carburetor support made of bungee cord and ruber distance tubes (picture).
The picture shows as well the 2 rubber joints which formerly supported the carburetor weight, but which are now not longer needed. They can be replaced by two M6x30 screws (DIN 912).

Assembly order: Push the PVC tube over the small end of the alu adaptor, fix it with plastic clamp and first steel strap clamp. Fix its other end on the carburetor in the same way. Check the bending of the plastic tube, the carburetor should point towards the pilot. Finally attach the alu adaptor in the intake flange at the crank case with the third steel clamp.
Attention: If the carburetor was already equipped with the flange for the 2 rubber joints, this flange must be removed first! This can either be done by carefully clmaping the carburetor into a vice, heating up the flange quickly (so that internal plastic parts do not melt) and pull it off with pliers, or you cut it with a small cutting wheel (take care not to cut into the carburetor).
Fresh Breeze/Southern Skies can do this for you as well.

The intake silencer is attached with 2 rubber cords as shown on the picture. The lower rubber loop must sit under the flange of the angle piece!

The main fuel jet has to be replaced with a smaller one which comes with the kit.
That’s it – enjoy the power of your Monster again!


Part list

- Upper distance tube for the intake silencer: Ø 14x2, ca. 25 mm
- Lower distance tube for the intake silencer: Ø 14x2, ca. 80 mm
(has to be trimmed according to the picture! We enclose a longer piece!)

- tube for lower attachment of the intake silencer: Ø 10x2, ca. 230 mm
- 2 rubber cord clamps
- rubber cord: Ø 5 mm: ca. 480 mm top
- rubber cord: Ø 5 mm ca. 480 mm botton
Rubber cord has to be trimmed after assembly! Ends should be 20 mm longer than the plastic clamp.

- 2 Screws DIN 912 M6x30 with washer as replacement for the rubber joints
- Alu-Adapter
- 2 black plastic clamps
- 2 stainless steel band clamps 32-50 mm (the third comes with the motor)
- PVC spiral tube: 85 mm
- Main fuel jet: 170 (may have to be adjusted depending on the motor)