How to Change the Motorcycle Head Gasket on a Honda 150 Benly
- 1). Use a crescent wrench and a socket wrench to loosen the nuts holding the twin exhaust manifolds and pipes to the cylinder and motorcycle body via brackets. Put the exhaust manifolds aside.
- 2). Use a crescent wrench to open up the left side panel of the engine, to expose the front sprocket connection of the motorcycle's drive chain. Use the same tool to disconnect and remove the carburetor assembly on the other side, connected to the engine cylinder.
- 3). Use the socket wrench to loosen and remove the front drive sprocket, connected to the drive chain. Loosen and remove the drive chain from the engine. Pull the ignition cap off the spark plug and move it out of the way.
- 4). Use the socket wrench to disconnect the top cylinder frame nut, while holding the other side's bolt stable with a crescent wrench. Pull or tap the bolt out of it's socket -- so the cylinder top is now free of the frame. Place a wood block underneath the engine block, so it doesn't drop with the next step.
- 5). Use the socket wrench and a crescent wrench to loosen and disconnect the rear engine block bolt from the frame.. Tap the bolt out of the frame. Carefully wiggle and drop the engine block out, with the engine now free of the frame. Use the socket wrench to loosen the top bolt clamp on the head of the cylinder.
- 6). Carefully pull the top bolt section off. Do the same for the mid-cylinder section, allowing the pistons to slip through the bottom, if needed. Next remove the base cylinder section, again allowing the pistons to slip through. Clean up the engine base area and studs, to prepare for new gaskets. Replace the piston rings, if needed.
- 7). Place a new gasket on the bare cylinder studs and push it down, so that it's flat against the engine case the cylinder will sit on. Grease the cylinder base segment insides with new engine oil. Take the base cylinder segment and position it back on the studs. Slowly slide it down, squeezing the piston rings to fit them inside the cylinder.
- 8). Reinstall the cylinder mid-section. Place the top cylinder gasket next, after the mid-section is seated properly. Place the final cylinder head on top of the stack with the top gasket underneath. Attach new nuts and washers to the top of the cylinder studs. Tighten the whole assembly evenly, on all four cylinder studs. Reverse steps 1 through 5, to install the engine back into the motorcycle.
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