Haynes SU Carburettors Owners Workshop Manual 1850105065, 1850105898, 9781850105893, 9781850105060

Citation preview

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SU Carburettors Owners Workshop Mianual er

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Legg ten MIMI

Models covered All SU Type H, HD, HS and HIF (inc. ‘electronic’) carburettors, and auxiliary/automatic starting devices

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SS Paes THE BOOK

Haynes Publishing Group Sparkford Nr Yeovil Somerset BA22 7JJ England Haynes Publications, 861 Lawrence Drive Newbury Park California 91320 USA

Inc

Acknowledgements Thanks are due to Hobourn SU Limited of Wood Lane, Erdington, Birmingham, and to Burlen Fuel Systems Limited of Spitfire House, Castle Road, Salisbury, for the supply of technical data. Special thanks go to Plowman Motors of Yeovil, for supplying one of the project vehicles. The Champion Sparking Plug Company Limited supplied the illustrations showing the spark plug conditions, and Sykes-Pickavant supplied some of the workshop tools. Lastly, thanks go to all those people at Sparkford who helped in the production of this manual.

© Haynes

Publishing

Group 1989

A book in the Haynes Owners Printed by J. H. Haynes & Somerset BA22 7JJ, England

Workshop Co.

Ltd,

Manual

Sparkford,

Series Nr

Yeovil,

All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording or by any

information storage or retrieval system, in writing from the copyright holder.

without

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permission

ISBN 1 85010 506 5 British Library Cataloguing in Publication Legg, A. K. (Andrew K.). 7942SU carburettors owners workshop manual. 1. Cars. Petrol engines. SU carburettors. Maintenance and repair. Amateurs manuals |. Title Il. Series 629.2'533 ISBN 1-85010-506-5

Data

pee AS Whilst every care is taken to ensure that the information in this manual is correct, no iiability can be accepted by the authors or publishers for loss, damage or injury caused by any errors in, or omissions from, the information given.

Contents Page About this manual

4

Conversion factors

5

Safety first!

6

Part 1: Chapter 1 Theory of carburation

7

Chapter 2 The SU Carburettor

11

Chapter 3 General maintenance and servicing

14

Chapter 4 Overhaul

18

Part 2: Chapter 5 Type H

28

Chapter 6 Type HD

37

Chapter 7 Type HS

44

Chapter 8 Type HIF

54

Chapter 9 Auxiliary starting devices

75

Part 3: Appendix 1 Applications list

87

Appendix 2 Needle charts

107

Appendix 3 Needle cross-reference chart

122

Appendix 4 Jet identification information

126

About

this manual

UM This is a manual written for the do-it-yourself car owners whose Cars are fitted with SU carburettors. Because the carburettor is a fine precision instrument, the book has to assume a basic familiarity on the part of the reader. For example it assumes that the owner already knows how his car works, where the carburettor is fitted and how to set the ignition timing (if he doesn’t then he can easily learn by reading the Haynes Owners Workshop Manual for his car), taking up the ‘story’ from that basic familiarity. It takes out the operation of the carburettor, isolating it from the rest of the car, and explains its function and workings in full, only relating those to the others of the car when necessary. It is a complete, comprehensive manual for the SU carburettor in its own right. A great deal of mystique surrounds the carburettor, its function and tuning; this manual explodes that mystique and guides the owner through the theory, maintenance, overhaul and tuning, using only the

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necessary tools which any reasonably equipped home workshop will possess. It does not over-complicate the issue by giving superfluous information which is of no practical use. By definition it is not possible to dictate when to look at your carburettor, nor whether the law allowsyouto alter any setting on your car — in some countries environmental agencies specifically forbid it. It simply provides a guide and then the information on how to do it should you want to. Of course every effort is made to ensure that this book is complete and up-to-date. However,

it should be realised that modifications happening

in design and production are

all the time, even in retrospect.

Whilst every care is taken to ensure that the information in this manual is correct, no liability can be accepted by the authors or publishers for loss, damage or injury caused by any errors in, or omissions from, the information given.

Conversion

factors ¢

Length (distance) Inches (in) Feet (ft) Miles

&< >< x

=

Millimetres (mm) Metres (m) Kilometres (km)

=

Cubic centimetres

=

Litres (1) Litres (1) US quarts (US qt) Litres (1) Litres (1) US gallons (US gal)

=

Litres (I)

x< KX

0.0394 3.281 0.621

Inches (in) Feet (ft)

Miles

Volume (capacity) Cubic inches (cu in; in®) Imperial pints (Imp pt) Imperial quarts (Imp qt) Imperial quarts (Imp qt) US quarts (US qt) Imperial gallons (Imp gal) Imperial gallons (Imp gal) US gallons (US gal)

OK OK KKK KK x

(cc; cm’)

0.061 1.76 0.88 0.833 1.057 0.22 0.833

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