Full description: what is the purpose of this piece?

Masterpiece During high engine revision, this seal performs essential safety functions:

1. Peripheral sealing: He seals the outer part of the water chamber. Its diameter of 105 mm Allows it to go around the cylinder to avoid any leakage of liquid to the outside of the engine.

2. Maintaining cooling pressure: The cooling system of Rotax runs under pressure. This seal ensures that this pressure remains constant, thus optimizing the heat exchange and avoiding overheating.

3. Fluid resistance: Made of high-performance elastomer, it is totally inert against fuels, oils and cooling additives, avoiding, and the seal does not disintegrate or harden with time.

4. Total compatibility: This seal is universal for the range Rotax 125cc: Micro, Mini, Junior, Max (Standard & Evo) and DD2.

💡 Michel's trick

"Listen to me well: This big seal of 105, it is he who protects your engine from external water leaks. If you see the blue or orange liquid that pears on the fins of your cylinder, is not looking, it is cooked! My secret? When you put it in the throat of the cylinder, make sure that it is not sprayed on itself. An O-ring 'twisted' loses 50% of its effectiveness. And as I always say: seal disassemble = seal replaced. For the price it costs, we do not take the risk of spoiling a final for a water leak!"

🎓 TUTO: mounting and maintenance of the 70x2,5mm seal

1. Preparation of the seal plan: Clean the outer throat meticulously on the top of the cylinder. There must remain no calamine residue or old limestone deposit.

2. Positioning: Remove the seal in its throat. Thanks to his section of 2.5 mm, it must exceed very slightly from the surface of the cylinder, which allows the crushing and sealing at the clamping.

3. Installation trick: So that it stays well in place while you put the red cylinder head, you can put 4 small silicone grease points very fine at the bottom of the throat. It will make "suction cup".

4. Final tightening: Once the cylinder head places, tighten the cross screws to 30 nm. This uniform tightening is crucial for the 105 seal being not pinched or sheared.