Crankshaft Core for OS Speed 12TZ Spec-2 - OS21532120 by O.S. Engine  [OS21532120]

O.S. ENGINES CRANKSHAFT OS SPEED 12TZ SPEC-2
Price:
NZD$46.94
Brand:
O.S. Engine
Model:
OS21532120
GTIN:
4531028141520
Condition:
Brand New
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alt="O.S. ENGINES CRANKSHAFT OS SPEED 12TZ SPEC-2" title="O.S. ENGINES CRANKSHAFT OS SPEED 12TZ SPEC-2"

Engine crankshaft compatible with OS Speed 12TZ

This crankshaft is an OEM-design replacement part for RC-scale nitro engines identified as OS Speed 12TZ Spec-2, intended for direct engine rebuilds and maintenance. It serves as the rotating core inside the engine case, providing the counterweight and journal surfaces required to convert piston motion into rotational output within a model engine.

When rebuilding, focus on cleaning bearing seats and checking the runout and balance of the OS21532120 crank. Correct preparation of mating surfaces and attention to journal finish will prolong service life and keep the engine running smoothly under load.

Replacing a fatigued crankshaft is often necessary to restore consistent mechanical timing and reduce the vibrations that upset idle stability and throttle modulation in nitro applications.

Specifications

  • Item: Crankshaft, OS Speed 12TZ Spec-2
  • Model Number: OS21532120
  • Brand: O.S. Engine
  • Compatibility: OS Speed 12TZ series engines

Fit this OS21532120 crankshaft when servicing an OS Speed 12TZ Spec-2 engine, and be sure to check related bearings and seals during installation.

How does this crank influence long-term durability?

A properly balanced crank like the OS21532120 reduces cyclical stress and vibration, which helps bearings and seals last longer under typical running conditions.

What material or workmanship signs indicate a problem?

Look for uneven machining marks, visible scoring on journals, or imbalance in the counterweight; any of these suggest the part should not be used without corrective work.

Can rebalancing extend its service life?

Minor balancing tweaks can help, but if the crank shows wear or damage, replacement with a correct OS21532120 unit for the OS Speed 12TZ Spec-2 is the reliable option.

How should I store the crank before fitting?

Keep it in a clean, dry container and avoid contact with corrosive substances; apply a light film of oil to journal surfaces if the part will sit for an extended period.

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