Exhaust Header Nut for FS120SII/FT120/FT160/FF320 - O.S. Engine OS45526400  [OS45526400]

What the Exhaust Header Nut Does

This M12 exhaust header pipe nut fits as an OEM-style part for RC nitro engines, providing the threaded connection that holds the header and tuned pipe to the engine flange. It keeps the joint sealed and aligned through the thermal and vibrational stresses typical of model operation.

Compatibility is limited to the model codes listed in the product title; confirm your engine model before installation. The nut chiefly secures the flange to maintain pipe position, which can influence exhaust backpressure and the engine's throttle response when tuning.

Installation notes: begin threading by hand to prevent cross-threading, then use the correct wrench and apply modest torque to seat the nut without deforming the flange. Inspect the fitting after initial runs and again following demanding sessions, as heat and vibration may loosen fasteners over time.

Practical tip for adjustments: when changing a tuned pipe or altering its length, release the header nut just enough to slide the pipe into place, verify alignment, and retighten to preserve a repeatable seal and consistent performance effects.