User Manual

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STEP 7: Remove the 3x23mm roundhead machine screws that fasten the header to the engine. Carefully remove the header to avoid damaging the gasket. To separate the engine from the engine mount, remove the four 3x8mm caphead machine screws.
REBUILDING THE ENGINE STEP 1: Remove the 4mm locknut from the front pipe hanger. Pull the pipe from the rear exhaust header
STEP 2: Unplug the blue wire from the glow plug. Remove the fuel line from the carburetor inlet and from the exhaust header pressure fitting. Disconnect the red and black wires from the EZ-Start motor. STEP 3: Remove the EZ-Start gearbox by removing the three 3x8mm roundhead machine screws.
STEP 4: Use a 2.5mm hex driver to remove the yellow ground wire from the engine mount. Move the EZ Start wiring harness out of the way.
STEP 5: Use a 2.5mm hex driver to remove the three remain- ing 3x10mm caphead machine screws from the engine mount.
STEP 6: Pull the engine from the chassis. Turn the engine so that the throttle linkage to the carburetor will come out.
STEP 9: Changing the piston and sleeve assembly Use a 5/16 inch nut driver to remove the glow plug and copper gasket.
STEP 10: Use a 2.5mm allen wrench to remove the four 3x12mm cap head screws that fasten the cylinder head. Rock the cylinder head gently from side to side to release it from the sleeve. Note the thin aluminum head gaskets. We recommend that you replace these gaskets with
new ones upon reassembly.
STEP 11: Remove the backplate and the starter shaft. Replace the backplate gasket with a new one during assembly.
STEP 12: The piston and sleeve are a matched set. When the piston and sleeve are disassembled, they must be reassembled in the same orientation. Use a hobby knife to scratch a mark to indicate the location of the piston in relation to the pinning of the sleeve.
STEP 8: Removing the carburetor is not necessary to rebuild the engine, unless you intend to replace the internal bearings of the engine. Remove the carburetor by loosening the 3mm locknut and pulling the carburetor straight up.
NOTE: Pro .15 engine is shown. The rebuild steps for the TRX .15 in the Nitro sport are the same as the Pro .15. Before rebuilding your TRX .15 engine, consider upgrading to a new TRX Pro .15 with the Traxxas Lifetime Engine Replacement Program. Contact Traxxas or your hobby shop for details.