The Small Workshop

1959 - Herb Uhl Trail Super Cub The CT90 traces its origins to Herb Uhl, a motorcycle dealer in Boise, Idaho, who modified the newly imported Honda Super Cub to increase its appeal to his customers, many of whom wanted a cheap and robust motorcycle to get…

Chains stretch during operation as material wears from the bushings and pins, increasing the clearance between components.

The CT90 has a simple ignition system, consisting of a power source (a battery), a switching device to start and stop current flow at set intervals (contact breaker points), a device to produce a high voltage (ignition coil) and a spark plug. 💡 If you just

My CT90 was in fairly typical condition for the CTs we get in the UK: a few missing and mismatched parts but otherwise in sound condition with minimal corrosion on account of having spent its previous life in California. 1969 CT90 K1 - this is a one-year…

Here is the wiring diagram for the lighting system.

wheels The CT90 use the same 1.40 x 17" wheels that Honda had been using on their Super Cubs since the 1950s.

The newer seat design is significantly larger, on account of the wider fuel tank introduced in 1972. the post 1973 model is a seat more suited to our increasingly well upholstered rear ends.

There follows a short description of how the CT90 charging system works.

loose ball steering head bearings If your bike has had a hard life you may find that corrosion or wear on the steering head bearings makes the steering feel notchy or stiff, in which case these parts will need replacing. the outer ring on my Ct90 shows si…

The engine in my 1969 CT90 K1 is not original and comes from an earlier (1968) bike, which created a useful opportunity to see how the engine evolved over time. cam chain tensioner Bikes from this era came with one of Honda's earliest attempt at a automat…

Early crankcase design flaw The crank and cases were largely unchanged during the long run of the 89cc Honda engine, the main change being to the kick-starter.

Turn signals - or 'winkers' as Honda refer to them - became a standard fixture with the late 1973 K4 model.

The speedo used on the 1969 Ct90 k1 speedometer is a one-year-only version with a distinctive triangular shape.

Welcome to the first instalment of an account on the work I did to repair the 1969 Honda CT90 K1 shown below.

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