GT15HZ Crankcase Plug OS28151300 by O.S. Engine  [OS28151300]

Overview: GT15HZ replacement plug

The O.S. Engine OS28151300 crankcase plug is the designated replacement for GT15HZ-series crankcases on RC glow engines. It provides the closure that protects internal components while the engine is running or being adjusted on the bench.

For installation: remove the existing plug, examine the seat and any gasket or O-ring, remove grit, and press the new plug into the bore. Hand-thread until it seats securely and avoid excessive torque to prevent thread stripping; then verify a full seal before completing reassembly.

When tuning, a correct crankcase seal helps preserve pressure and prevents contaminants from entering, supporting repeatable carburetor and ignition settings. Use this plug as part of regular inspections or when replacing worn internals and confirm the seal after any crankcase opening.