Metrakit Pro Race Crankcase for mopeds with Derbi D50B1 engines with balance shaft.

High-performance crankcase from the Pro Race range, designed for Derbi D50B1. Developed specifically for racing use, this engine casing is suitable for both 50cc and big-bore kits.

The casing accepts standard 50cc - Racing 88cc cylinder kits with long standard type cylinder studs, without the need to machine the cases. It is fully compatible with the original derbi gearbox, clutch, & ignition, making installation straightforward.

The cylinder base also has the space and stud pattern to accept a flange mounted 70cc cylinder kit.

The intake has been re-engineered for larger flat-slide carburettors and is designed to work with a V-Force 3 or 4R reed block to improve airflow.

With the starter motor removed, the Metrakit crankcase is considerably lighter than the standard item; reducing overall engine mass while increasing strength and improving bike handling.

Specifications:
Material: Cast aluminium
Cylinder compatibility: (standard 50-88cc or flange mount 70cc)
Stroke compatibility: 39mm-45mm

Professional assembly and tuning required. For racing use only!

6304TN9 C3 (20x52mm) crankshaft bearings required.

To use this engine as a replacement for D50B0 engines (without balance shaft) you would need to blank off the balance shaft seal, behind the crankshaft.

700C0080