Honda CT90 - turn signals

Honda CT90 - turn signals

Turn signals became a standard fixture on the CT90s in 1973 following the introduction of federal legislation in the USA that made them mandatory on all cars and motorcycles. Retrofitting them to older bikes is straightforward...

Turn signals became a standard fixture on the CT90s in 1973 following the introduction of federal legislation in the USA that made them mandatory on all cars and motorcycles. Retrofitting them to older bikes is straightforward...

Honda CT90 K1 speedometer

Honda CT90 K1 speedometer

The speedo used on the 1969 Ct90 k1 speedo is a one-year-only version with a distinctive triangular shape. My bike was fitted with a later version - the replacement I found is shown in the middle below. Although almost identical to the K1 model, the version I managed to get hold of is actually from...

The speedo used on the 1969 Ct90 k1 speedo is a one-year-only version with a distinctive triangular shape. My bike was fitted with a later...

Honda CT90 K1 Recommissioning

Honda CT90 K1 Recommissioning

The first instalment of a short account on the work I did to repair the 1969 Honda CT90 K1 above. The jobs required were largely repairs and recommissioning...

The first instalment of a short account on the work I did to repair the 1969 Honda CT90 K1 above. The jobs required were largely repairs and recommissioning...

New - Transmission Ghost theme

New - Transmission Ghost theme

I developed the theme used on this site from scratch and have made it available as free open source software....

I developed the theme used on this site from scratch and have made it available as free open source software....

Honda C90Z - wiring diagrams

Honda C90Z - wiring diagrams

Here are copies of the colorised wiring diagrams I created, based on the original Honda black and white diagrams. If you aren't familiar with reading this type of diagram (it is not has hard as it first appears!) then you can read more about them here: Honda C90 - electrical system overviewElectricity Learning...

Here are copies of the colorised wiring diagrams I created, based on the original Honda black and white diagrams. If you aren't familiar...

Setting Up Nginx for Ghost

Setting Up Nginx for Ghost

The recommended web server for Ghost installations is Nginx. The software has a number of features in addition to its HTTP server capabilities - including caching, load balancing and more - but the bits we are most interested in when running a simple blog site are the web server and reverse proxy. As the name...

The recommended web server for Ghost installations is Nginx. The software has a number of features in addition to its HTTP server capabilities - including...

Comments enabled!

Comments enabled!

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,...

Honda CT90 - carburettor and air cleaner

Honda CT90 - carburettor and air cleaner

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...

Honda C90 - Cylinder inspection

Honda C90 - Cylinder inspection

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 CT90 - posi-torque sub transmission

Honda CT90 - posi-torque sub transmission

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...

Honda C90 - cam chain & cam chain tensioner

Honda C90 - cam chain & cam chain tensioner

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. As a result, when Honda replaced the Super Cub push-rod engines with a new chain-driven overhead cam model they needed to incorporate a chain tensioner to...

Chains tend to 'stretch' in use because material wears away from the bushings and pins, increasing the clearance between the parts and causing...

Honda CT90 - making a wiring harness

Honda CT90 - making a wiring harness

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,...

Honda CT90 - muffler and spark arrester

Honda CT90 - muffler and spark arrester

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...

Honda CT90 - Front Suspension

Honda CT90 - Front Suspension

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...

Honda CT90 - wiring diagrams

Honda CT90 - wiring diagrams

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...

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 be done at home if...