Tuning cylinder kit ZT75N Stage 1 (75cc) - for Simson KR51/1 Schwalbe, SR4-2 Star, SR4-3 Sperber, SR4-4 Habicht

ZT75N Stage 1 cylinder kit


For a long time, there were only very few more powerful cylinders available for the KR51/1. This is due to unfavorable channel routing, and with more powerful kits, one quickly reaches the thermal load limit. With only 2 oversize pistons, the durability of such gray cast iron cylinders was also limited.
The cooling body and the running sleeve are made of high-quality aluminum casting. The running sleeve is coated in a special process, which makes it extremely robust and protects it optimally against wear.
The thermal conductivity is also significantly higher than with a cylinder variant with a gray cast iron sleeve. In addition, the heat dissipation is further improved by a blasted, slightly rough surface.
Thus, the 2 core problems could already be eliminated by the use of new technologies.
The timing and channel cross-sections have been designed for high torque from low revs and a wide power band to harmonize perfectly with the 3-speed gearbox. Thus, the drivability from low revs is absolutely identical to our "old tuning cylinders". In addition, however, the power in the middle and upper speed range could be significantly increased, which ultimately enables a power band and power development that is otherwise unmatched in this class.

Features:
- Original look cylinder with coated aluminum sleeve
- High-quality material for cooling body and running sleeve
- Improved heat dissipation through blasted surface and coated aluminum sleeve
- Long durability, approx. 10,000 km per piston (multiple oversizes available)
- Vmax 85-90 km/h
- Approx. 9.5 hp

Scope of delivery:
- ZT75N cylinder (running sleeve diameter 54mm)
- ZT75N cylinder head (externally centered)
- ZT 1-ring piston Ø49 mm including ring, pin & clips
- Carburetor flange gasket
- 2x cylinder base gasket
- 2x carburetor flange studs

Note:
The bore of the original engine housing must be enlarged to 54 mm (engine housing must be reamed out).
A BB crankshaft should be used.
The original clutch must be reinforced (conversion to 5-disc clutch KR51/1).
A tuning air filter must be used (air filter KR 51).

Only Motul 800 2T Road Racing must be used as mixing oil!

Use rubber buffers (10070259) for exhaust mounting! With rigid mounting, the exhaust manifold thread may break!