
The legend is back—and bigger than ever! The legendary Metrakit racing cylinder from days gone by has risen like a phoenix from the ashes in its 45 mm version, reigniting the passion in your Puch Maxi S, N, X30 Sport NS, NL, and Supermaxi LG1 and LG2 mopeds.
The aluminum cylinder with a gray cast iron liner is an optimized replica of the original Metrakit racing cylinder. The valve timing has been revised compared to the original and features more exhaust advance, making the well-known piston seizure problem caused by high heat generation a thing of the past. In addition, the cylinder height has been precisely adjusted, so that the extra-thick base gasket previously required is now unnecessary.
This GPO racing cylinder is among the strongest and most powerful in its class and has been extensively tested. It delivers robust torque across the entire power band and offers impressively powerful performance. Thanks to the optimizations compared to the original, the cylinder also achieves a noticeably higher RPM, which provides even more power and riding enjoyment.
To get the most out of this tuned cylinder, we recommend using at least a 15-mm carburetor. However, you’ll achieve noticeably more power with a 17-mm carburetor. Thanks to the generous 19-mm intake, you’ll have plenty of headroom for optimal power delivery.
Note: The cylinder is shipped loose and without a piston, gasket set, studs, or other mounting parts.
A high-quality, affordable standard replacement part. GPO – GOOD PARTS ONLY.
| Manufacturer | GPO |
| Camouflaged | No |
| Material | Aluminum, Gray cast iron |
| Surface | varnished |
| Displacement | 70 ccm |
| Crankshaft stroke | 43 mm |
| Nominal diameter | 45 mm |
| Ø cylinder neck | 47.8 mm |
| Ø outlet inside | 26 mm |
| Ø Inlet inside | 19 mm |
| Number of fixing points | 4 pcs |
| Thread inlet | M6x1 (standard thread) |
| Hole spacing outlet | 42 mm |
| Area of application | Tuning, Racing |
| Hole spacing inlet | 38 mm |
| Ø piston pin (B) | 12 mm |
| Hole pattern [mm] | 44 x 44 |
| Outlet type | straight |
| Thread outlet | M6x1 (standard thread) |
| Puch | E50 ZA50 (air-cooled) Z50 (X30 Sport) |
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