Honda C90 - carburettor - cleaning and replacement parts

Honda C90 - carburettor - 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 rough idea of how these parts work – the fixes are straight forward and largely common sense. A note of warning from the early workshop manuals: Engine trouble during acceleration is caused...

There are only a few things that can go wrong with the simple carburettors used on the Honda c90 and – once you have a rough...

C90 carburettor
Honda C90 - carburettor choke

Honda C90 - carburettor choke

Fuel evaporates poorly at lower temperatures and, when the engine is cold, tends to condense on the walls of the intake manifold and cylinder making the engine hard to start. The solution is to make the mixture richer, either by temporarily adding more fuel or by restricting the amount of air. The mechanism used on...

Fuel evaporates poorly at lower temperatures and, when the engine is cold, tends to condense on the walls of the intake manifold and cylinder making...

C90 carburettor
Honda C90 - carburettor idle circuit

Honda C90 - carburettor idle circuit

The idle circuit, sometimes called the pilot or slow circuit, controls the mixture of fuel and air at low throttle speeds. There are not many components involved, read on to see how they work together to ensure the engine ticks over smoothly at low revs. Pilot jet The orifice in the pilot jet is tiny...

The idle circuit, sometimes called the pilot or slow circuit, controls the mixture of fuel and air at low throttle speeds. There are not many...

C90 carburettor
Honda C90 - carburettor main circuit

Honda C90 - carburettor main circuit

The carburettors fitted to the C90 super cub have two independent systems for metering fuel and air, the main circuit and the idle circuit. The idle circuit is designed to control the mixture of fuel and air at low throttle speeds and the main circuit determines the mixture at higher engine speeds (you can get...

The carburettors fitted to the C90 super cub have two independent systems for metering fuel and air, the main circuit and the idle circuit. The...

C90 carburettor
Honda C90 - carburettor fuel supply

Honda C90 - carburettor fuel supply

Parts The engine needs a constant supply of fuel – the parts involved are marked on this picture of the dismantled carburettor: * fuel tap * float bowl * float * float valve Fuel supply The fuel is fed to the tap by gravity from the tank where: 1. It passes through a filter and up through the hole marked...

Parts The engine needs a constant supply of fuel – the parts involved are marked on this picture of the dismantled carburettor: * fuel tap * float bowl...

C90 carburettor
Honda C90 - carburettor overview

Honda C90 - carburettor overview

One of the first things I did when trying to get my old Honda C90 to run was to clean the carburettor, having read that it might have become clogged up with old fuel while it was in storage. I did eventually get it to run but it didn’t idle well and was hard...

One of the first things I did when trying to get my old Honda C90 to run was to clean the carburettor, having read that...

C90 carburettor
Honda C90 - wheel refurbishment

Honda C90 - wheel refurbishment

It is difficult to find an old C90 without knackered wheels and mine was no exception. I am not sure what the wheels had been painted with but it was rock hard and there was no way they could be cleaned up satisfactorily, so I decided to replace the spokes and rims. There are three...

It is difficult to find an old C90 without knackered wheels and mine was no exception. I am not sure what the wheels had been...

C90 chassis
Honda C90 - engine & hub paint

Honda C90 - engine & hub paint

I used VHT SP995 CAST Aluminium Engine Enamel Paint to paint the engine cases and wheel hubs.  The cases had been repainted once before so I couldn’t really tell if it is a good match or not ( perhaps a bit sparkly? ).  Apparently the original paint used by Honda was called Silver Cloud but I...

I used VHT SP995 CAST Aluminium Engine Enamel Paint to paint the engine cases and wheel hubs.  The cases had been repainted once before so...

C90 Engine
Honda C90 - Seat refurb

Honda C90 - Seat refurb

The seat was a bit of a mess:  despite having been repainted several times it was rather rusty on the underside, particularly around where the hand strap is fixed on (all the used c90 seats I’ve seen on ebay are the same – I suppose rain must get blown underneath and trapped between the seat...

The seat was a bit of a mess:  despite having been repainted several times it was rather rusty on the underside, particularly around where the...

C90 chassis
Honda c90 z2 - introduction

Honda c90 z2 - introduction

Introduction Honda’s Super Cub step-through motorcycle is the most successful motor vehicle ever built and a staggering number – well over 100 million – have been sold. I was lucky enough to find a low mileage 1978 C90 for sale a few miles from where I live. It ran for about half a mile before conking...

Introduction Honda’s Super Cub step-through motorcycle is the most successful motor vehicle ever built and a staggering number – well over 100 million – have been...

C90 carburettor
The Record Imp Vice

The Record Imp Vice

The Record Imp is the brilliant tiny cousin of the Record #74 Auto Vice. I use my Imp constantly, it  really is a very useful vice despite its small size (the jaws are only 2 1/4” wide).   If you are in the UK then you can get them for around 20-30 quid on eBay...

The Record Imp is the brilliant tiny cousin of the Record #74 Auto Vice. I use my Imp constantly, it  really is a very useful...

vices
Record 74 Auto Vice Cleanup

Record 74 Auto Vice Cleanup

The Record 74 Auto Vice still show up for sale fairly regularly in the UK. This one was a bit grotty cosmetically but in good mechanical condition: The only minor issue was that at some point the pin that retains the washer/spring used to hold the handle against the moveable jaw had broken and...

The Record 74 Auto Vice still show up for sale fairly regularly in the UK. This one was a bit grotty cosmetically but in good...

Record Tools Ltd
the Record 52 ½ vice - a timeline

the Record 52 ½ vice - a timeline

Here is a short summary of the history of the Record 52 ½ vice. You can read more about this vice here and information on the other vices mentioned can be found here. 1877-1910 The earliest quick release vices were know as "instantaneous grip" vices. Wilson Riley and and an unknown inventor working for...

Here is a short summary of the history of the Record 52 ½ vice. You can read more about this vice here and information on the...

Record Tools Ltd
coffee table - finished

coffee table - finished

finished! Here is the finished coffee table with the two side tables: A reasonable success I think: there are enough similarities between the side and coffee tables so they seem part of a set, yet the coffee table design is much more sturdy. A fun project and I am pleased I have made something from...

finished! Here is the finished coffee table with the two side tables: A reasonable success I think: there are enough similarities between the side and...

coffee table
coffee table - legs and aprons

coffee table - legs and aprons

The plan is that the legs will be splayed 6 degrees and tapered on two sides. I will keep the top bit square and start the taper from beneath the aprons. My reasoning was that if the tapers went straight through to the top I would need to get the tapers exactly the same on...

The plan is that the legs will be splayed 6 degrees and tapered on two sides. I will keep the top bit square and start...

coffee table
coffee table - design

coffee table - design

I have replaced both my horrible Furniture Land side tables with home made versions  and now the coffee table has to go too.  Initially I thought I would try and keep to a similar design to the side tables, albeit with beefed up the cross members and legs: But I was concerned about the strength...

I have replaced both my horrible Furniture Land side tables with home made versions  and now the coffee table has to go too.  Initially I...

coffee table