I have finally got the comments section of the site working. If you'd like to suggest corrections; ask questions or make a comment, please feel free. No swearing!
You will need to supply an email address (look for the banner at the end of a post) and then check your inbox for an...
I have finally got the comments section of the site working. If you'd like to suggest corrections; ask questions or make a comment,...
This article contains a brief survey of the different carburettors fitted to CT90 range, and an in depth look at the the K28A installed on my CT90 K1. The K28 carb was used on the K1-K3 (1969-72) models, and is very similar to the subsequent 556a model that was used until 1977.
carburettor models
The...
This article contains a brief survey of the different carburettors fitted to CT90 range, and an in depth look at the the K28A installed on...
Checking your cylinder is within the service limit involves measuring the bore with a cylinder gauge as shown in the following diagram:
What follows is what I've found out about this process from research and experimentation, but please note that I'm not an engineer and I'm just doing this...
Checking your cylinder is within the service limit involves measuring the bore with a cylinder gauge as shown in the following diagram:
What follows is...
Honda invented the posi-torque system in 1967 and used it on the CT90 range of the same year. This ingenious device had the effect of providing the bike with 4 additional hillclimbing gears in addition to the standard 4 ratios for road-riding
Earlier solutions
The posi-torque system replaced the unwieldy dual rear sprocket arrangement used...
Honda invented the posi-torque system in 1967 and used it on the CT90 range of the same year. This ingenious device had the effect of...
Chains tend to 'stretch' in use because material wears away from the bushings and pins, increasing the clearance between the parts and causing the chain to elongate. So when Honda replaced the Super Cub push-rod engines with a new overhead cam model that used a chain to drive the mechanism they needed a...
Chains tend to 'stretch' in use because material wears away from the bushings and pins, increasing the clearance between the parts and causing...
The CT90 has a simple wiring harness and making a replacement is pretty straightforward. Much of the wring on my 1969 K1 had been damaged, cut or patched so I decided to do a major overhaul, including making a brand new harness. Here are the before and after picture of the various repairs:
making a...
The CT90 has a simple wiring harness and making a replacement is pretty straightforward. Much of the wring on my 1969 K1 had been damaged,...
The CT90 exhaust system, although similar in appearance to the one used on the 6v C90, has different internals with fewer baffles and the addition of a Krizman spark arrester.
Spark Arresters
Spark arresters are designed to minimise the risk of fires being started by exhaust sparks and are required in the US when using...
The CT90 exhaust system, although similar in appearance to the one used on the 6v C90, has different internals with fewer baffles and the addition...
The earliest CT90s shared the same leading link suspension as the C90 Super Cubs. This is a great design, offering a comfortable ride and minimising maintenance issues by tucking the moving parts away from the elements. However, the forks were designed for road use and therefore only allowed a small amount of suspension travel; not...
The earliest CT90s shared the same leading link suspension as the C90 Super Cubs. This is a great design, offering a comfortable ride and minimising...
I have just finished recommissioning a 1969 CT90 K1. The bike was originally sold in the US and was imported to the UK from California a few years ago.
One of the many repairs that needed doing was to replace the damaged wiring harness, so I colourised the wiring diagram to help with the job....
I have just finished recommissioning a 1969 CT90 K1. The bike was originally sold in the US and was imported to the UK from California...
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 be done at home if...
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, you will be faced with...
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 other. This article covers the...
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 turn and thus converting the...
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 is transmitted through a fairly...
The c90 uses a drum brake design that is essentially unchanged since it was first introduced over 120 years ago.
Renault drum brake
Drum brakes were first patented by Louis Renault in 1902 (see the patent diagram below left). Despite its apparent simplicity this invention was a huge improvement on the previous alternatives which had...
The c90 uses a drum brake design that is essentially unchanged since it was first introduced over 120 years ago.
Renault drum brake
Drum brakes...
This post explains the design of the Honda Super Cub suspension and steering. If you are interested in fitting tapered roller bearings instead of the standard ball bearing used in the steering head then see here.
Leading Link Forks
All the Honda Super cubs since their introduction in 1958 until relatively recently were fitted with...
This post explains the design of the Honda Super Cub suspension and steering. If you are interested in fitting tapered roller bearings instead of the...
