This 2 stroke carb tuning guide will give you all the information you need to tune your 2 stroke carburetor for peak performance, no matter the make or model. Engine output increase of two stroke combustion with exhaust system optimization michal. Jennings book talks about port time area and porting the cylinder to have peak efficiency at a certain rpm. Computer software can help you with the design, but dont expect super design from the. Pdf improving the performance of twostroke motorcycle with. For example, a cc engine may produce 125 hp in stock form and 175 hp after race tuning. Ten motorcycles that remind us why we miss twostrokes.
Exhaust and intake tuning this article describes the principles involved in using tuned exhaust and intake systems on twocycle and fourcycle engines. You would burn about a gallon of oil every 1,000 miles if you used a two stroke engine in. Carburetor s for twostroke engines and longer ones on carburetor s for fourstroke engines. Twostroke engines making comeback motorbike writer. Ogbor department of mechanical engineering, ambrose alli university, ekpoma edo state, nigeria. The lack of a dedicated lubrication system means that the parts of a two stroke engine wear a lot faster. Contents chapter 1 introduction 9 chapter 2 the cylinder. Those of us who have grown up in the japanese two stroke. Two stroke engines dont last nearly as long as four stroke engines. The rgv250 was released in the uk in 1989 to widespread acclaim the first production 250 which could reach mph and spawned a whole ministocks production race series. Motorcycle tuning twostroke 1994 edition open library. Improving the performance of two stroke motorcycle with tuned adjustable exhaust pipe o. Two stroke performance tuning two stroke all of these detonation triggers are virtually unavoidable, with the exception of excessive spark lead.
The effect of higher compression ratio in twostroke engines. The twostroke engine is widely used in both motorcycle racing and kart racing, and in very large numbers in model car, boat and aircraft competition. Improving the performance of twostroke motorcycle with. Engine output increase of twostroke combustion with. Researchers have found that it is the gases at the very outer limits of the combustion chamber, called the end gases, that selfignite to cause detonation. Pdf two stroke performance tuning download full pdf. Jenning vs graham bell, 2 stroke tunning books motorcycle.
Be assured that teachers, industry representatives, and various others have been involved to make this publication usable, readable, and by all means basic enough to be easily used. The two stroke dirt bike engine building handbook diy. The effect of higher compression ratio in twostroke engines yuh motoyama and tohru gotoh yamaha motor co, ltd. Twostroke engines do not use fuel efficiently, so you would get fewer miles per gallon. Everything you need to know about the twostroke cylinder. Tuned adjustableexhaust pipe for use on two stroke motorcycle was designed and tested. If this does not describe you please stop and seek professional help as engine damage and serious injury can result from. You would burn about a gallon of oil every 1,000 miles if you used a twostroke engine in a car. Booktopia has motorcycle tuning twostroke, motorcycle tuning s. Performance tuning basic twostroke tuning the tuned exhaust system how twostroke expansion chambers work, and why you should care expansion chambers.
Horsepower for a complete explanation of what horsepower is and what it. Pdf motorcycle tuning two stroke download full pdf. Two stroke performance tuning chapter 3 porting and cylinder scavenging today, when we take a look down the cylinder of a two stroke engine, we find its walls literally filled with ports to handle the induction, transfer and exhaust phases of gas flow through the engine. Exhaust and intake tuning building, tips and techniques. The most common mistake is to choose the wrong combination of engine components, making the engine run worse than stock. However, due to transit disruptions in some geographies, deliveries may be delayed. Tuning for speed is considered by many knowledgeable motorcycle enthusiasts to be one of the best books ever written on how to improve, modify and fine tune a motorcycle engine and it is often referred to as one of the top 10 classic motorcycle books. Tuned adjustable exhaust pipe for use on twostroke motorcycle. Graham bell is an acknowledged expert on engine tuning, with many years experience in this field. Improving the performance of twostroke motorcycle with tuned adjustable exhaust pipe o. However, ktm has released a raft of new directinjection twostrokers and honda recently registered patents for directinjection twostroke engines, so they look like making a comeback. Whether your a professional mechanic or a novice this video will show you all you need to know to properly set the idle mixture. Bigger carburetors, higher compression ratios, altered port timings and expansion. Motor cycle tuning twostroke by robinson, john, 1994, newnes edition, in english 2nd ed.
Ogbor department of mechanical engineering, ambrose alli. Two stroke performance tuning chapter 3 porting and cylinder scavenging today, when we take a look down the cylinder of a twostroke engine, we find its walls literally filled with ports to handle the induction, transfer and exhaust phases of gas flow through the engine. Unless you have a deep passion for twostroke tuning, are willing to spend money on software and porting equipment, and are comfortable throwing away botched cylinders, i would recommend having a reputable professional carry out any desired port modifications. Hello select your address best sellers todays deals new releases todays deals new releases. Bells fourstroke performance tuning book, this book goes into extreme detail regarding performance tuning a twostroke engine. In other words, the engine will, after tuning, produce more power from the same displacement. If you look at a carburetor, you will notice a rather large hole going from one side to the other. Amal tuning guide in pdf 557 kilobytes make your own tuning wheel. On two stroke carburetors this is an air screw so dont forget turning the screw out is a leaner mixture. The basicexhaust tuning mechanisms was described w ith respect to a twostroke singlecylinder engine.
The results show that actual fuel consumption can improve by % for each unit increase. How to tune your motorcycle for performance and fuel. Not content with being one of the premier parts suppliers in the uk from world renowned companies, such as brembo, dymag, samco to name but a few. Those of us who have grown up in the japanese twostroke. Do you want it to be full range, still strong at low rpm or do you want it for higher power at rpm even if that means you will loose some low rpm. This guide aims at tuning the fuelair screw to give you an optimal airfuel mixture. The two stroke dirt bike engine building handbook is the most comprehensive guide for dirt bike engine building available, whether you are working at home or as a professional in a shop. Pdf improving the performance of twostroke motorcycle. Two stroke tuners handbook 2 another mistake commonly made, sometimes even by those who have enjoyed some success in modifying twostroke engines, is to believe in a kind of mechanistic magic.
Two stroke performance tuning twostroke all of these detonation triggers are virtually unavoidable, with the exception of excessive spark lead. You basically want the ports to be as large as possible, without going too high on its duration. Describe working principle of two stroke cycle and four stroke cycle engines. Two stroke cylinder porting tips watch this before you start cutting. Oct 17, 2017 tips on how to port a two stroke cylinder, what to donot do and how to do it right. How to trim a 200820 ktm air boot not required carburetor detailed views. May be the following will help you in tuning your mean machine for optimal power delivery and best fuel economy.
Advanced twostroke tuned exhaust system the challenge the society of automotive engineers clean snowmobile challenge 2002 sae csc 2002 is an engineering. Basic 2 stroke tuning changing the power band of your dirt bike engine is simple when you know the basics. Two stroke and four stroke engines, working principles, applications types, power and efficiency heat engine is a machine for converting heat, developed by burning fuel into useful work. Ktm and honda have both registered patents for directinjection two stroke engines. There are different phases taking place in the crankcase and in the cylinder bore at the same time. The mechanical simplicity of the twostroke engine gives it tremendous appeal, and makes it a tempting target for tuning operations, but the key to successful design, development and modification. Chassis by john robinson for free with a 30 day free trial. An optimal mixture gets maximum performance from your machine. Although a twostroke engine has less moving parts than a fourstroke engine, a twostroke is a complex engine because it relies on gas dynamics. His port time equations dont even include rpm, you input the dime. Graham bell starts off by saying that he doesnt believe port time area and its all about the duration the ports are open.
Osprey motorcycle tuning chassis isbn 0434917249 motorcycle tuning fourstroke isbn 0434917435 motorcycle tuning twostroke isbn 040800830x also, robinsons tech articles in performance bikes magazine very readable, with some mathcomputer stuff john robinson, heinemann professional publishing. Service tuning and overhauling of motorcycle engine. The two stroke engine is widely used in both motorcycle racing and kart racing, and in very large numbers in model car, boat and aircraft competition. Twostroke oil is expensive, and you need about 4 ounces of it per gallon of gas. Two stroke moped tuning two stroke timing moped tuning. The port heights, widths, areas, directions they flow, and relationships to one another all have a significant influence on how the engine will behave. Systematic method of removing an engine from a motorcycle.
It has the determining influence on engine outgoing parameters for engines with a twostroke operating cycle. The idle mixture screw is only one facet of overall carburetor jetting, however it is one of the first places to start when diagnosing a poorly running bike. The process of building twostrokes to race engine quality is explained indepth in this thoroughly illustrated handbook. To form a proper homogeneous inflammable mixture of fuel and air to supply the engine with varying amounts of this mixture. For particular requirements, such as on some racing engines, carburetor s with air intakes having a. Suzuki motorcycle manuals pdf, wiring diagrams, dtc.
The effect of higher compression ratio on fuel consumption and power output was investigated for an aircooled twostroke motorcycle engine. Two stroke oil is expensive, and you need about 4 ounces of it per gallon of gas. We specialise in honda 2strokes, covering the cr range of motorcross bikes, the nsr250 street bikes, and hrc grand prix 125, 250, and 500s. Buy a discounted paperback of motorcycle tuning twostroke online. Two stroke engines were phased out by tough pollution laws and fuel economy targets, but they could be making a comeback with ktm, honda and boutique builders. Properly tuned systems can increase the charge of fuel delivered to the cylinders and a related phenomenon can aid. Gordon jennings twostroke tuners handbook was written in the early heyday of twostroke, motorcycle roadracing, dragracing and motocross. Aug 17, 2015 during thelast 20 years two stroke motorcycles have practically vanished from the streets, substitutedby cleaner, safer and more reliable fourstrokes. Improving the performance of twostroke motorcycle with tuned. October 1966 marked the first year for the companys debut beautiful road racing motorcycle suzuki 250 t20. A two stroke cylinder consists of exhaust, transfer, and occasionally inlet ports true inlet ports are only found on piston or rotary valve controlled engines. The first thing you need to do when tuning a two stroke is to determine its characteristics. It has the determining influence on engine outgoing parameters for engines with a two stroke operating cycle. Previous searches had unearthed usable but poor quality.
Exhaust and intake tuning this article describes the principles involved in using tuned exhaust and intake systems on two cycle and fourcycle engines. Basic starting settings for 2 stroke dirt bike carbs running standard fuels. Tuned adjustableexhaust pipe for use on twostroke motorcycle was designed and tested. Two stroke cylinder porting tips watch this before you. Other books to his credit are modern engine tuning, twostroke performance tuning and forced induction performance tuning. Two stroke motorcycles have been phased out in recent years by tough pollution laws and fuel economy targets. This two stroke engine tuners document contains the formulas, theory, examples and illustrations to literally turn anyone into a professional two stroke engine guru. Twostroke motorcycles have been phased out in recent years by tough pollution laws and fuel economy targets. A guide to the choice, setting and use of tapered needle motorcycle carburetors page. Pdf two stroke performance tuning download full pdf book. The vj21 refers to the suzuki model code for the bike vj21, vj22 and vj23 were the rgv series of two stroke twofifties, with the 21 and 22 sharing many parts in common. Pdf two stroke performance tuning algadwie egantara. Motorcycle 2stroke premium pump uel reuire or hih compression ratios up to ix\.
Engine output increase of twostroke combustion with exhaust. This 2stroke carb tuning guide will give you all the information you need to tune your 2stroke carburetor for peak performance, no matter the make or model. This book, now long out of print, was the bible of twostroke performance engine builders and racers and its a treasured addition to any mechanics library. I have the book, but its nice to have as a pdf as well and a good reference for those who dont know about it. Download pdf tuning for speed free online new books in. Introduction and aims an exhaust system is an important supplement of all engines. Oct 24, 2017 10 ways to gain power in a 2 stroke engine for free. Dellorto motorcycle carburetor tuning guide 1 functions of the carburator. I usually recommend this book along with gordon jennings two stroke tuners handbook, because this book has what the first one doesnt and vice versa.
Tips on how to port a two stroke cylinder, what to donot do and how to do it right. We also offer the customer a complete bespoke tuning service so they to can feel that spine tingling rush only a two stroke can provide. Engine output increase of twostroke combustion with exhaust system optimization michal. They were in the business of manufacturing economical twostroke motorcycles and. A myriad of different aftermarket accessories is available for you to custom tune your bike to better suit your needs. Gordon jennings was a life long motorcycle enthusiast and writer who worked as an editor for cycle magazine and motorcyclist magazine. Motor cycle tuning two stroke by robinson, john, 1994, newnes edition, in english 2nd ed. The basicexhaust tuning mechanisms was described w ith respect to a two stroke singlecylinder engine. It can be said that heat engine is equipment which generates thermal energy and transforms it into mechanical energy. Pdf motorcycle tuning two stroke download full pdf book.
To prepared and train a student to become a motorcycle mechanic to earn a respectable living and learners will be able to work as. Aussie twostroke engine invention motorbike writer. Twostroke motorcycle engine maintenance and repair. He really talking abour a mixwre of fuel and oil if yoll rjchen rhe premix ratio 20. Below is a number of turns that will get your rod set to a basic, ballpark, starting setting. Nov 11, 2010 jennings book talks about port time area and porting the cylinder to have peak efficiency at a certain rpm. The mechanical simplicity of the two stroke engine gives it tremendous appeal, and makes it a tempting target for tuning operations, but the key to successful design, development and modification. The objective of tuning is to improve the volumetric efficiency of the engine. However, ktm has released a raft of new directinjection two strokers and honda recently registered patents for directinjection two stroke engines, so they look like making a comeback.