Carburettor- Bing carburettor parts breakdown (German).
Carburettor Tuning - Puch Service Bulletin No. 57, Sept 1969 (English).
Carburettor Tuning - Puch Service Bulletin No. 57, Sept 1969 (German).
Carburettor - Incorrect assembly warning.
Ensure that the Jet Needle 'R' clip (Clamping Spring, Bing p/n 61-375, Puch p/n 175.3.15.013.1) is fitted with the straight leg facing forward, towards the piston return spring. If reversed, the piston spring could foul the round section of the clip causing the throttle to jam open.
Crankshaft Oil Seal Replacement - Instructions showing how to replace these seals.
Crankshaft Oil Seal Replacement (Youtube Video) - See 'Links' Page.
Cylinder Installation (Youtube Video) - See 'Links' Page.
Engine Strip - Motorcycle Mechanics (Sep 1969) article.
Flywheel Holding Tool Drawing - Simple home-made tool for use with engine in frame.
Flywheel Holding Tool Instructions - How to use the above tool.
Handbook - Sears SR125 (Specifications, Operating & Maintenance, Wiring Diagram and Trouble Shooting).
Kickstart Shaft Seal Replacement - Instructions showing how to change this seal.
Petroil Mixture - Puch specified SAE50 engine oil, in the ratio of 1:25, but the use of modern mineral or semi-synthetic 2-stroke oil in the ratio of 1:33 can be used without adverse effects and with the benefit of producing less smoke.
Rear shock absorber overhaul - Instructions showing how to carry this out.
Repair Instructions Pt 1 - Sears SR125. Engine.
Repair Instructions Pt 2 - Sears SR125. Chassis and Electrical Equipment.
Spark Plugs - List of suitable plugs.
Special Tools - Sears SR125.
Specification - Specification
Sump Cooling Fins - Never checked them? Nor had I, until now.
Torque Figures - Tightening of critical fasteners.
Two-Stroke Engine Runaway - I'd never heard of this but it's what's been happening to my bike.
Wiring Diagram - M125.
Wiring Diagram - M125 (UK & Sears).
Wiring Diagram - M125 De-Luxe.
Wiring Diagram - M125 De-Luxe with bar end indicators.