Honda C90 - crankshaft refurbishment

Honda C90 - crankshaft refurbishment

There are plenty of places that will rebuild your crankshaft for you, but it is also a job that can be done at home if you have the right equipment. tools You'll need a press (minimum 10 ton) to remove the pin and to reassemble the crankshaft and you’ll also need some...

There are plenty of places that will rebuild your crankshaft for you, but it is also a job that can...

Honda C90 - putting it back together

Honda C90 - putting it back together

Intro If you have dismantled your bike in order to refurbish it then, once you have finished reassembling the engine, you will be faced with a large pile of bits that need putting back together. In the immortal words of the old Honda manuals: "Perform the reassembly in the reverse procedure of disassembly."...

Intro If you have dismantled your bike in order to refurbish it then, once you have finished reassembling the engine,...

Honda C90 - air cleaner and exhaust

Honda C90 - air cleaner and exhaust

It hardly needs saying but the engine only works when air gets in one end and exhaust gasses exit the other. This article covers the two systems on either end of the engine, the air cleaner and the exhaust. Muffler and exhaust pipe Although in the UK we tend to refer generically to "exhaust...

It hardly needs saying but the engine only works when air gets in one end and exhaust gasses exit the...

Honda C90 - Crankshaft

Honda C90 - Crankshaft

The forces created by combustion pressure are transferred to the piston through to the connecting rod, causing the crankshaft to turn and thus converting the reciprocating motion of the piston to rotary motion. Here's what I learned about how it works. construction The connecting rod is located on the crankpin and the webs[...

The forces created by combustion pressure are transferred to the piston through to the connecting rod, causing the crankshaft to...

Honda C90 - transmission and performance

Honda C90 - transmission and performance

The transmission takes energy from combustion and transmits it to the rear wheel. The mechanism is shown below: The power is transmitted through a fairly convoluted path before it reaches the rear wheel: energy created by combustion forces the piston downwards causing the crank to rotate. The crank rotation is then transmitted through the clutch...

The transmission takes energy from combustion and transmits it to the rear wheel. The mechanism is shown below: The power...

Honda C90 - piston, cylinder and combustion

Honda C90 - piston, cylinder and combustion

Internal combustion engines convert the chemical energy stored in fuel into the mechanical energy used to power machines when the fuel air mixture is compressed in the space between the piston and the cylinder head and ignited by the spark plug. The design of the piston, cylinder and cylinder head plays an important role in...

Internal combustion engines convert the chemical energy stored in fuel into the mechanical energy used to power machines when the...

Honda C90 - lubrication

Honda C90 - lubrication

The first Super Cubs did not have pumped lubrication, instead the crank, piston and cylinder were splashed by oil thrown up by a dipper on the big end of the connecting rod. A similar device can be seen in towards the end of this excellent video about engine lubrication: As shown in the diagram above,...

The first Super Cubs did not have pumped lubrication, instead the crank, piston and cylinder were splashed by oil thrown...

Honda C90 - automatic clutch

Honda C90 - automatic clutch

The history of the automatic clutch used in Honda's Super Cub motorcycles can be traced back to the 1940s.  Soichiro Honda's early success with auxiliary engines had shown him there was a market in Japan for inexpensive motorised two wheeled  transport.     By the mid 1950s he had begun to think of...

The history of the automatic clutch used in Honda's Super Cub motorcycles can be traced back to the...

Honda C90 - cam chain tensioner

Honda C90 - cam chain tensioner

When Honda replaced the Super Cub push-rod engines with a new overhead cam model in the mid 1960s they needed to deal with the problems arising when using a chain to drive the camshaft from the crank. Cam chains tend to elongate as the bushings and pins wear with use and - without a mechanism...

When Honda replaced the Super Cub push-rod engines with a new overhead cam model in the mid 1960s they needed...

Honda C90 - cam chain

Honda C90 - cam chain

Given that the cam chain is one of the components that determines cam to crank timing thereby preventing your piston and valves from colliding they get very little attention in the Honda workshop manuals. Cam chain stretch Although I was aware that chains 'stretch' with use, I confess I had a vague notion...

Given that the cam chain is one of the components that determines cam to crank timing thereby preventing your piston...