4 stroke motorcycle tuning book

Theres little point in going out to buy a 4 stroke with the intention of tuning if you got even half way to a 2 strokes power its going to be a hell of a lot less reliable. Open library is an open, editable library catalog, building towards a web page for every book ever published. A reference book for the enthusiast engine tuner and race engine builder. I understand how exhaust back pressure works on a 2 stroke, but can someone please explain why it would be desirable on a 4 stroke reading up ive read that back pressure keeps the fuel mixture from escaping the combustion chamber before it can be efficiently ignited but why would any fuelair mixture be escaping on an exhaust stroke.

Ten motorcycles that remind us why we miss twostrokes. Motorcycle tuning four stroke by robinson john 0600333655 the. This fully revised and updated edition is one of the most comprehensive references available to engine tuners and race engine builders. The book provides access to the most frequently used data for dealers, mechanics and enthusiasts who have to deal with a wide variety of machines and wish to compare the features of different models. My smaller friend at 190 lbs can do the same at almost 30 mph flat land 15 uphill. Contents chapter 1 introduction 9 chapter 2 the cylinder. Mar 16, 2012 stroking a four stroke engine also increases the displacement making the bike illegal for ama pro racing. A book for all interested in two stroke engines, their tuning and testing and in the intriguing problems of two stroke design. This site uses cookies to help us provide quality services. Nick swager secrets of speed todays techniques for 4. Once thought too polluting, the twostroke engine makes a comeback in advance of stricter fuel efficiency standards. Jan 06, 2011 the process of building 4 stroke engines to a professional standard, from selecting materials and planning work, right through to methods of final assembly and testing, written for the diy engine.

Two stroke performance tuning a disc partially cut away and attached to the end of the crankshaft opens and closes an inlet port in the side of the crankcase. The rpm spread between the torque peak and the power peak is influenced by the engines rodtostroke rs ratio see chapter 2. The process of building 4stroke engines to a professional standard, from selecting materials and planning work, right through to methods of final assembly and testing, written for. The last 250 twostroke manufacturer of road bikes in japan was suzuki and aprilia had used the suzuki vtwin 250 twostroke motor for the rs250, but with suzuki ceasing production aprilia no longer had a supply of motors and the 2004 model was their last production run the very last example of a breed of motorcycle which will hold a special. It is very important to understand that tuning a single item fitting bigger. The morbidelli 125 twin road racer is a rotary valve engine. Aug 17, 2015 during thelast 20 years two stroke motorcycles have practically vanished from the streets, substitutedby cleaner, safer and more reliable fourstrokes. Golden eagle bike engines andrews 4 stroke motorized. Bigger carburetors, higher compression ratios, altered port timings and expansion.

A study of the fourstroke motorcycle engine book, 1970. How to tune and modify motorcycle engine management systems. And, just as the bikes themselves have changed, so have the tools with which we tune them. Cant go wrong with a good 4 stroke engine, just change the oil and make sure it all stays tight. Basic concept of tuning a 4 stroke petrol engine the.

The motor is very quiet, its a honda gx35 4 stroke, has excellent power. Stroking a fourstroke engine also increases the displacement making the bike illegal for ama pro racing. Tuning 125 4 stroke i think all of those bikes are more commuters than sporty especially the excessively heavy comet. Im not sure what book youre reading joe, but all the stuff ive learned over the years tells us shorterfatter for top end like a dragster setup and longer skinnier for low end. Fourstroke performance tuning 4th edition haynes publishing. Drawing on the authors many years of practical experience in tuning and. Is my bike 2stroke or 4stroke and what does it mean. For example, a cc engine may produce 125 hp in stock form and 175 hp after race tuning. It gives me 36 mph on average, that includes a 300 pound driver and speeds over 100 mph and it i. There are many ways to boost the power, one of which is by installing a tuned pipe.

To me, two stroke engines are plain an simple outdated technology. When attempting to tune up a motorcycle, consider these main points. Nov 03, 2017 tune your car, motorcycle, lawnmower, rc model, chainsaw etc. To stroke an engine, a tuner relocates the bigend bearing further outboard on the crank. Graham bell is an acknowledged expert on engine tuning, with many years experience in this field.

We cover that, as well as other mods on a four stroke engine. This classic has been completely updated for the second edition. The piston crown opens and closes the exhaust and transfer ports. Two stroke motors are more efficient that four strokes for a few reasons. Other books to his credit are modern engine tuning, twostroke performance tuning and forced induction performance tuning. Mar 12, 2008 hi, im looking at buying a nice little 4 stroke for my first bike just to act as a commuter and to get my experience up. How to increase performance of 4stroke motorcycles. The is an introduction to tuning with a programmable electronic fuel injection ecu. Paul m brokaw suggestions for routine and advanced tuning work. Also that any backpressure and ive seen proof of this on a dyno, like restricting the end will cost you power on a 4 stroke. The free flow exhaust system is as important as the above mentioned points to enhance the power and performance of the 4 stroke motorcycle. Honda mini 4stroke engines offer robust performance, 360. Dec 24, 2002 thought id better kick the new section off by writing an article for it myself, on the subject of 4 stroke engine tuning, no specific to minis, but all totally relevant. Buy or build a better exhaust pipe4 strokes are quieter than 2 strokes to begin with and re jet the carb.

Also that any backpressure and ive seen proof of this on a dyno, like restricting the end will cost you power on. Mastering exhaust system math to build highperformance engines. I refer to this book and its companion book on 4 stroke engine tuning regularly for information and would feel lost without them. Im 245 lbs with an additional 20 lbs of gear on me and my bike cruises at an easy 20 mph with minimal pedaling 9 mph up the steepest hills and im not even breaking a sweat. Motorcycle tuning 4 stroke, second edition 2nd edition by john robinson author. 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. In other words, the engine will, after tuning, produce more power from the same displacement. The tips in this video can be applied to most carburetor equipped vehicles and tools.

They are so simple and fun that ive always enjoyed tinkering with them. Everyday low prices and free delivery on eligible orders. The inlet port opens 30 after bdc and closes 79 after tdc. Motorcycle tuning four stroke by robinson john 0600333655. Dont expect a lot of nutsandbolts info, however, its mostly theoretical, but very useful. This is aimed at people with little or no knowledge of engines or how to tune them, ive pitched it at a very basic level, its far more an intrudction than any sort of. He has served as a tuner for american and european offroad racing teams, and he resides near chicago, illinois.

Fourstroke performance tuning in theory and practice. How to tune and modify motorcycle engine management. My exhaust is there, its even intact, but where it connects to the exhaust part of the engine, it is detached and half of the exhaust comes out from the bottom, not from the muffler. This book provides a very solid basis of understanding the 4cycle engine, properly. Thought id better kick the new section off by writing an article for it myself, on the subject of 4 stroke engine tuning, no specific to minis, but all totally relevant. Motorcycle tuning 4 stroke, second edition robinson, john on. This fully revised and updated edition is one of the. My bmw flat twin engine is good for running 100,000 miles without major overhaul.

On one hand, jetting changes can give you an inexpensive means to instantly increase horsepower, throttle response and power characteristics. Similarly, a longer rod tends to move the peaks closer together. First published in 1989 as tuning new generation engines, this bestselling book has been fully updated to include the latest developments in fourstroke engine technology in the era of pollution controls, unleaded and lowlead petrol, and electronic management systems. It covers everything from fuel types, cam specs, headbottom end modifications, coolinginduction etc etc, and not only discusses what can be done, but also what is and isnt worth. Hi, im looking at buying a nice little 4stroke for my first bike just to act as a commuter and to get my experience up. Eric gorr, who runs the highly respected motorcycle modification shop forward motion and its companion website, is dirt riders dr. There are many after market exhaust pipes available, always use the exhaust system which fits your bike perfectly and never use loose fitting exhaust as leakage of the exhaust gasses may hamper the utility. During thelast 20 years twostroke motorcycles have practically vanished from the streets, substitutedby cleaner, safer and more reliable fourstrokes. This book really does cover all aspects of tuningmodifying a 4cylinder naturally aspirated engine and is therefore applicable to the majority of na cars in the uk. How to tune your carb carburetor tuning tips and tricks. Motorcyle tuning by john robinson overdrive rakuten. Fourstroke motocross and offroad performance handbook.

Tune your car, motorcycle, lawnmower, rc model, chainsaw etc. Motorcycle tuning twostroke 1994 edition open library. The free flow exhaust system is as important as the above mentioned points to enhance the power and performance of the 4stroke motorcycle. Motorcycle tuning 4 stroke by john robinson, paperback. It is written specifically for megasquirt or megasquirtii efi users who are new to tuning engine with a programmable controller, and tries to make very few assumptions about what you already know. The author explains how various stages of engine tune are reached, and describes typical development work with enough theory to devise a practical development programme. Jul 03, 2011 the last 250 two stroke manufacturer of road bikes in japan was suzuki and aprilia had used the suzuki vtwin 250 two stroke motor for the rs250, but with suzuki ceasing production aprilia no longer had a supply of motors and the 2004 model was their last production run the very last example of a breed of motorcycle which will hold a special. For more information on the new suzuki df60a 4stroke outboard for 2010 or the companys leading lineup of advanced 4stroke outboards. Using our services, you consent to the use of cookies. Dec 05, 2018 im not sure what book youre reading joe, but all the stuff ive learned over the years tells us shorterfatter for top end like a dragster setup and longer skinnier for low end. The problem is that if i were to get a 125cc 4stroke it would be barely kicking out more power than my old aprilia rs50, which was tuned to the point it did 80mph. Given a constant stroke length, a shorter rod tends to broaden the separation between the torque peak and the power peak. Drawing on the authors many years of experience in tuning and modifying highperformance road, rally and race units, every aspect of an engines operation is explained and analyzed.