Meteor Piston Item number: MP1806556N
Meteor Piston

METEOR ITALY Replacement Pistons for Piaggio/Gilera 180 cc 2-stroke LC engines with original Gilardoni cylinders – available in four sizes ranging from Ø65.55 to Ø65.58 mm.

Key Specifications: METEOR ITALY Piston for Piaggio Gilera 180

Manufacturer: METEOR ITALY
Engine: Piaggio/Gilera 180 cc LC 2-stroke
Nominal bore: Ø65.60 mm
Piston Sizes: M 65.55 / N 65.56 / O 65.57 / P 65.58 mm
Compression stroke: 30.00 mm
Piston pin: Ø16 × 54 mm
Piston rings: 2 pieces, 1.5 mm
Weight: approx. 197 g
Manufacturing: Gravity casting
85,00 €*
available immediately
Shipping weight 0,33 kg

METEOR ITALY Pistons for Piaggio/Gilera 180 cc 2-stroke – Ø65.55 to Ø65.58 mm

The METEOR ITALY P1645 pistons are a high-quality and cost-effective alternative to the original Piaggio/Gilera pistons for water-cooled 180-cm³ two-stroke engines with Gilardoni cylinders. The pistons match the geometry and installation dimensions of the stock parts and are available in four finely graded diameter classes.

This allows the required piston clearance to be precisely matched to the actual measured cylinder diameter. This is a major advantage, especially with used cylinders: Instead of using a one-size-fits-all piston diameter, the appropriate size can be selected based on a measurement.

METEOR ITALY P1645 Ø65.55–65.58 mm Piston pin Ø16 mm 2 piston rings Gravity Cast

Key Benefits

Geometry close to production specifications: compatible with original Piaggio/Gilera 180-cm³ Gilardoni cylinders
Four sizes to choose from: increments in just 0.01 mm
Precise clearance adjustment: Piston diameter can be selected to match the actual measured cylinder diameter
Complete piston kit: piston pins, retaining clips, and two piston rings are included
Affordable alternative: high fit accuracy without the extra cost of an original replacement part

For Piaggio/Gilera 180 cc LC 2-stroke

The piston is designed for water-cooled Piaggio/Gilera 180-cm³ two-stroke engines with an original Gilardoni cylinder. Typical applications include:

Gilera Runner FXR 180
Italjet Dragster 180
Piaggio Hexagon LXT 180
Other models with a corresponding Piaggio/Gilera 180-cm³ LC 2-stroke engine and a Ø65.6-mm cylinder

Four size options in 1/100-mm increments

The letters M, N, O, and P do not denote different piston designs, but rather precisely graded diameter classes. The piston diameter increases by only 0.01 mm from one category to the next.

Available piston categories

Category Piston Ø METEOR Reference SC Part Number Calculated Bore Clearance for a Cylinder with an Exact Diameter of 65.60 mm
M65.55 mmPC1645MMP1806555M0.05 mm
N65.56 mmPC1645NMP1806556N0.04 mm
O65.57 mmPC1645OMP1806557O0.03 mm
P65.58 mmPC1645PMP1806558P0.02 mm

The specified clearances are calculated based on an actual measured cylinder bore of exactly Ø65.60 mm. The actual cylinder diameter is always the determining factor for piston selection.

Which piston size is the right one?

For a new, original cylinder with an actual bore of approximately 65.60 mm, the smallest category, M (Ø65.55 mm), results in a calculated clearance of approximately 0.05 mm.

In a cylinder that has already been run in, the bore may have increased due to wear. In this case, selecting a larger piston may be advisable to restore the proper clearance. However, it is not the mileage alone that is decisive, but the actual measured cylinder dimension.

Measure Cylinders Before Ordering

For used cylinders, we strongly recommend a professional measurement of the cylinder bore. The diameter, ovality, and conicity should be checked.

Only based on these measurements can you determine which piston category will provide the desired clearance. A larger category should not be selected solely based on estimated mileage.

METEOR – a high-quality alternative to the original piston

METEOR ITALY manufactures pistons for numerous European production and aftermarket applications. This model corresponds to the original Piaggio/Gilera application but is offered directly under the METEOR brand and without Piaggio markings.

This provides a dimensionally accurate, high-quality replacement solution at a more attractive price than the piston sold as an original replacement part.

Piston Design

The P1645 is manufactured using the gravity casting process. METEOR specifies its weight as approximately 197 g.

The compression height is 30.00 mm, and the total length is 64.50 mm. The piston crown features a barrel-head design with a specified crown height of 2.50 mm.

Piston Pin and Rings

The piston uses a piston pin with a diameter of 16 × 54 mm. The system also includes matching retaining clips and two piston rings.

Piston pinØ16 × 54 mm
Retaining clipsØ16 × 1.2 mm, C-shaped
Piston rings2 pieces
Ring size according to METEOR65.6 × 1.5 × 2.7 mm

Technical Specifications

ManufacturerMETEOR ITALY
METEOR ReferenceP1645
EnginePiaggio/Gilera 180 cc LC 2-stroke
Nominal Cylinder BoreØ65.60 mm
Piston diameterØ65.55 / 65.56 / 65.57 / 65.58 mm
Compression stroke30.00 mm
Head shapeBarrel Head
Head height2.50 mm
Total length64.50 mm
Piston PinØ16 × 54 mm
Piston rings2 pieces, 1.5 mm
Weightapprox. 197 g
Manufacturing processGravity Casting

Package Contents

1x METEOR piston in the selected size
1x piston pin, Ø16 × 54 mm
2x Piston pin retaining clips
2x Piston rings

Installation Instructions

Measure the cylinder bore precisely before selecting the piston
Determine the clearance based on the actual cylinder dimensions
For used cylinders, also check for ovality and conicity
Check piston rings for correct end-to-end alignment and fit before installation
Insert the piston pin clips correctly into the designated grooves
If in doubt, have the cylinder and piston measured by an engine rebuilder

Conclusion

The METEOR P1645 is a very interesting replacement option for the original Piaggio/Gilera 180-cm³ piston. The four finely graded sizes allow for precise adjustment of the piston clearance to the actual cylinder diameter.

This range of sizes offers a major advantage, especially with used Gilardoni cylinders: After professional measurement, the appropriate piston size can be specifically selected, rather than judging the cylinder solely by its nominal dimension.

FAQs about the METEOR P1645

The letters denote different piston diameters. M corresponds to 65.55 mm, N to 65.56 mm, O to 65.57 mm, and P to 65.58 mm. The increment is 0.01 mm in each case.
With an actual measured bore of exactly 65.60 mm, category M (65.55 mm) results in a calculated clearance of 0.05 mm. However, the actual cylinder dimension should still be checked before making a selection.
A larger category may be appropriate for a worn or enlarged cylinder. However, the selection should always be based on a measurement of diameter, ovality, and conicity—and not solely on the running clearance.
Yes. This P1645 version is designed for the original Piaggio/Gilera 180-cm³ application with a 65.6-mm Gilardoni cylinder. The correct size must be selected based on the measured cylinder diameter.
The kit includes the piston in the selected size, the Ø16-mm piston pin, two retaining clips, and two piston rings.