Honda C90 – correct valve clearance
Because the consequence of too tight valve gaps can be serious, it is sometimes said that a ‘noisy tappet is a happy tappet’ (the noise …
Honda C90 – valve clearance
Once you have the engine back together an important job is to adjust the valve clearance (sometimes called “valve lash” or “tappet gap”). The clearance …
Honda C90 – valve seals
The valves are held in place by metal guides installed in the cylinder head and on some C90s (including the c90 z2) there is a …
Honda C90 – valve removal, cleaning and lapping
Before you remove the valves you have to take off the tappet covers. A common problem is that these covers seize tight in the cylinder head and …
Honda C90 – valve timing
Here are a few posts on the topic of valve timing and valve adjustment. Happily, since the c90 is such a simple engine, it is …
Honda C90 – tool kits
Looking at the CMSL microfiche parts diagrams, the older Kowa tool kits – for example the c100 from the 1960s – contained: an open ended 10/14mm spanner …
Kowa tools
Kowa Seiki have made tools for Honda since 1956, initially making their special workshop tools and then going on to make the tool kits for …
Honda C90 – carb – cleaning and replacement parts
There are only a few things that can go wrong with the simple carburettors used on the Honda c90 and – once you have a …
Honda C90 – carb choke
When the engine is cold fuel tends to condense on the walls of the intake manifold and cylinder and this make the engine hard to …
Honda C90 – carb idle circuit
The idle (or “pilot”) circuit controls the mixture of fuel and air at low throttle speeds. Here are the bits involved in the pilot circuit …