for Vespa 180-200 Rally/ PX80-200/ PE/ Lusso/ Cosa/ T5
brown seal
metal

Grade AA – first-class repair Product description
Assured sealing of the crankshaft found in the Vespa largeframe engines.

Many experienced Vespa mechanics see the crankshaft oil seal for the main clutch-side bearing as a major weak point of the largeframe engine. A narrow fixing-bore surface combined with a relatively large contact diameter with the crankshaft. A combination that quickly tests both the quality of its production and installation. When this crankshaft oil seal fails then you are faced with the task of a complete overhaul of the engine.
Assured sealing qualities.
Precise dimensions and fit.
Extended service interval.

This crankshaft oil seal does not necessarily have to be such a problematic weak point. A quality crankshaft oil seal, constructed using more modern materials, with exact dimensioning should last many years and miles and cause no problems. This depends of course that its seating in the crankcase is in perfect condition and it is properly mounted, including some form of locking.

The suitable materials, not to mention a higher production quality, have fortunately been around for a while now. We would at this point like to recommend two examples of these modern advantages:
1.
MALOSSI
(Part. No. M6616201)
This crankshaft oil seal by provides solutions to all questions and problems otherwise encountered when replacing or upgrading this part. A high end inner sealing lip made from PTFE combined with a steel frame. The outer seating edge is polished, ensuring precision and an exact fit. The oil seal is a tidy and enduring solution, providing years of care-free operation when fitted to largeframe engines requiring this type of seal. Personally recommended by Zini at Stoffis Garage and Jesco from Scootershop.
2. Original PIAGGIO/
ROLF
black/rubber-coated (Part. No. #91014000)
Regrettably the quality of the original PIAGGIO parts is very inconsistent. Sometimes cheap parts are sourced in the far-east and suppliers are often changed. Luckily, since 2017, PIAGGIO has been having these particular oil seals produced by a renowned manufacturer and they are of a reliable quality. Since this partnership was established all largeframe engines that require this seal have been provided with this black, rubber-coated version which is produced by ROLF – and they have gained themselves a good reputation. As long as PIAGGIO remain with this supplier and this seal, it can be also recommended for reliability and quality. Numerous scooter dealers swear by this seal and use it exclusively, from standard PX 80 set ups through to full-blown tuning projects. They are personally recommended by Nico at Schall und Rauch and Tim from Vollbart-Motorroller.

We also have a selection of other popular clutch-side bearing crankshaft oil seals available:
3.
CORTECO
brown/metal
Very popular and widely used crankshaft oil seal including a PTFE sealing lip. While mounting pay special attention to the clearance between the seal and the adjacent bearing.
4. CORTECO blue/rubber
Readily incorporated into many engine casings including a groove in the crankcase seating of the seal.

We also have two cheaper versions available for customers on a strict budget, although we do not recommend trying to save money with these crucial components!
5. CORTECO blue/metal
A version of the brown CORTECO but produced using a cheaper material for the sealing lip.
6. ROLF black/rubber
Common and cheaper version of the original PIAGGIO crankshaft oil seal, manufactured with simpler production techniques and standards.

Conclusion
: In view of our recommended and PIAGGIO versions, this hard working component can no longer be considered as the Achilles heel of the Vespa largeframe engines!
The best set up ?C our SIP?CTIP:

No crankshaft oil seal lasts longer than its adjacent bearing: Clutch-side crankshaft bearing, high-carbon steel, nine ball-bearings (#15559050).
The flywheel-side crankshaft oil seal should not be ignored and also be of high quality, flywheel-side crankshaft bearing FKM (#M6616198).
A damaged crankshaft oil seal seating in the crankcase can also be repaired: Crankshaft repair-sleeve from SKF, Speedisleeve (#15559050).

Zini, STOFFIS GARAGE, Austria 09/2020:

“We always use the sheet metal oil seals in PX Lusso engine casings. We haven’t had any problems since then.”
OEM numbers (for comparisons):
6616201B (MALOSSI)