1. Big Spring - Engine
Likely Component: This likely refers to a recoil starter spring (rewind spring) or a governor spring in the engine’s starting or speed control system.
Recoil Starter Spring: Found in manual pull-start systems, this large, coiled flat spring rewinds the starter rope after pulling. It’s housed in the recoil starter assembly, which engages the engine’s flywheel to crank the engine.
Governor Spring: A larger helical spring that connects the governor arm to the throttle linkage, controlling engine speed by balancing centrifugal force (from the governor) against spring tension. It’s critical for maintaining consistent RPM under load.
 
Function:
Recoil Starter Spring: Stores energy to retract the pull rope, ensuring the starter mechanism resets for the next pull.
Governor Spring: Regulates throttle opening to maintain engine speed, especially important in agricultural applications like plowing where loads vary.
Mechanical Buffalo Context: If the MB uses a manual pull-start (common in small agricultural engines), the “big spring” is likely the recoil starter spring. If it’s related to speed control (e.g., for consistent plowing), it could be the governor spring.
 
Specifications:
Recoil Starter Spring: Typically a flat, spiral steel spring, 4–6 inches in diameter when coiled, housed in a plastic or metal starter housing.
Governor Spring: A helical coil spring, often 2–4 inches long, with hooks or loops to attach to the governor arm and throttle linkage.
 
Common Issues:
Broken or weakened spring causes the starter rope to not retract or the engine to fail to crank.
Governor spring stretching or detachment leads to erratic RPM or engine stalling under load.
 
2. Spring Regulator
Likely Component: This likely refers to a governor spring (if distinct from the “big spring”) or a throttle return spring in the engine’s speed regulation or carburetor system.
Governor Spring: As above, regulates engine speed via the governor mechanism.
Throttle Return Spring: A smaller helical spring that returns the throttle valve to its idle position when the operator releases the throttle lever. It’s attached to the carburetor or throttle linkage.
 
Function: Ensures the engine returns to a set speed (governor spring) or closes the throttle to prevent over-revving (throttle return spring). Critical for safe operation and fuel efficiency in MBs used for plowing or heavy loads.
Mechanical Buffalo Context: Likely part of the governor system, as mechanical buffalos rely on governors to maintain steady speed under varying loads (e.g., plowing wet fields). If the engine has a manual throttle, the regulator spring could be a throttle return spring.
Specifications: A helical coil spring, typically 1–3 inches long, with specific tension and hook/loop ends to match the governor or throttle linkage.
 
Common Issues:
Stretched or broken spring causes unstable RPM, surging, or failure to return to idle.
Rust or dirt can reduce spring effectiveness, common in humid agricultural environments.

3. Small Spring
- Likely Component: This could refer to a valve spring, choke return spring, or a smaller governor/throttle spring in the engine or carburetor system.
Valve Spring: Compresses to allow intake/exhaust valves to open and close in the engine’s cylinder head. Small but strong, typically 1–2 inches long.
Choke Return Spring: A small spring in the carburetor that closes or opens the choke valve, aiding cold starts.
Small Governor/Throttle Spring: A secondary spring in the governor or throttle system for fine-tuning speed or returning smaller components to position.
 
Function:
Valve Spring: Ensures precise valve timing for combustion, critical for engine performance.
Choke Return Spring: Controls the choke valve for proper air-fuel mixture during startup.
Governor/Throttle Spring: Assists in speed regulation or throttle return, often paired with a larger spring.
Mechanical Buffalo Context: Likely a choke return spring (for starting the engine in humid or cold conditions) or a secondary governor spring, as MB engines are simple and rugged. Valve springs are less likely unless you’re overhauling the engine.
Specifications: A small helical spring, 0.5–2 inches long, with precise tension and end fittings (hooks or loops) to match the carburetor, governor, or valve assembly.
Common Issues:
Weak or broken choke springs cause starting issues or rich/lean fuel mixtures.
Weak valve springs reduce power or cause misfires.
Small governor springs failing lead to minor speed fluctuations.