Complete description of the product (H1: Balancing pendulum gear 27 teeth white plastic - motor Rotax Max)
The sliding gear 27 teeth made of white plastic is a piece of transmission of origin manufacturer (Original Rotax Racing). This technical gear settles inside the bas-engine to ensure the synchronized connection between the crankshaft and the balancing tree (pendulum) on all the engines of the range Rotax 125 Max (Junior, Senior, Master, DD2).
Designed in high-density white technical plastic lubricated by box oil, this gear fills an essential mechanical shock absorber role. The use of the polymer makes it possible to significantly reduce the operating noise of the motor and absorb high speed transmission micro-shocks, thus protecting the movable crew of the spurious vibrations. With its 27 teeth perfectly calibrated, it guarantees a balancing distribution timing of absolute accuracy.
Technical characteristics:
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Number of teeth: 27 teeth
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Material: Injected technical plastic (high white resistance polymer)
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Engine compatibility: Rotax 125 Max Fr, Junior, Senior, Master, DD2 (All versions)
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Location: Transmission housing / Low-motor (crankshaft bond)
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Origin: Certified original part Rotax (Essential for the technical passport in competition)
👨🔧 3. Tip in Michel (the corner of the expert)
* "Hi the artists of the mechanics! This white plastic pinion is the classic bas-engine revisions on the Rotax. Even if it is very sturdy, plastic ages with the hours of rolling, the temperature variations of the oil and the constraints at 14 000 rpm. A plastic plastic too old can lose teeth, and if the pendulum is shifting, the motor will vibrate like a tile until you risk breaking a crankcase !
My obligatory trick of old mechanic: be a surgical accuracy on the timing of benchmarks. The crankshaft pinion and the pendulum gable have small points (alignment marks) engraved on it. They must be perfectly aligned in front of the crankcase benchmarks according to the factory manual.
When going up the mountain circlips, always put new circlips and check that they are clipped in their throat. And do not forget: change these preventively plastic sprockets every 50 hours during great revisions. It's cheap and it avoids big damage! "*
📐 4. The Replacement & Calibration Guide: Step by Step
1.Vidange and opening:10 min.Place the kart on his carriage. Unscrew the drain screw under the housing to empty the gearbox oil. Remove the lateral clutch housing to access internal sandy.
2.Extraction from the worn gear:5 min.Using a suitable circlip clamp, remove the safety circlips that keeps the white pinion on its axle. Gently slide the spent of 27 teeth out of the shaft.
3.Alignement and posing new:10 min.Clean the axis to the brake cleaner. Present the new white plastic pinion. Apply the trick to Michel: Rotate the crankshaft and the pendulum to precisely align the factory setting marks before driving the gear thoroughly.
4.Security and closing:5 min.Install a new holding circlips in the shaft groove. Visually check that the timing has remained perfect by making two full turns to the engine by hand. Close the housing with a new seal and redo full with original box oil Rotax (XPS).
❓ 5. FAQ SEO (Frequently Asked Questions)
Q: Why is this pinion with plastic and not steel ?
A: The choice of technical plastic by the factory Rotax is purely mechanical. A plastic pinion drastically reduces metal friction and internal noise in the engine. In addition, it serves as a mechanical "fuse": in case of problem or abnormal blocking, the plastic pinion breaks to avoid destroying much more expensive parts such as crankshaft or motor housings.
Q: Should we replace the two dangling gears at the same time ?
A: Yes, it's strongly recommended. The balancing system usually uses a pair of sprockets that work together. To ensure uniform wear and avoid any premature game in the teeth, always change the gears per pair when revising the bottom-motor.
Q: Is it the official piece required to ride in the championship Rotax MAX CHALLENGE ?
A: Yes I do. This is the original certified piece bearing the official manufacturer reference. The use of non-original (adaptable) gears is strictly prohibited by the technical regulation of the FFSA and the League Rotax and causes immediate disqualification to technical control.