Lets all get together and start a two stroke tuning thread that rivals others in the world, as, we are all kiwis, and as such have an amazing pedagree particularly when it comes to high powered. On a stroker things like matching the ports to the liner, crankcase to transfers etc. The difference in power between a dirty and clean filter is probably more than the difference in power between a stock and aftermarket pipe. Improper routing caused this ca ble to fray above he carburetor. Good resources on cylinder porting and tuning in general include jennings two stroke tuners handbook, and two stroke performance tuning by a graham bell. I have a 02 sensor for my mustang wideband and also have thought many times of how easy it. There is a wealth of knowledge contained in this manual. Motor cycle tuning twostroke by robinson, john, 1994, newnes edition, in english. Graham bell is an acknowledged expert on engine tuning, with many years experience in this field. Everyday low prices and free delivery on eligible orders. Tuning the tsx the acura tsx has an excellent pedigree. It would be nice to move this in to the mainstream section of this site, and i hope we can do this shortly, however, good things take time, and some cooperation is needed.
This means that to run motax, you will need a post 2010 computer which is preferably a desktop, driven by an intel i7 4core processor. Open library is an open, editable library catalog, building towards a web page for every book ever published. An introduction to tuning 2 stroke motorcycles for those who want results straight out of the box. Balancing the crank dynamically, getting correct piston to bore clearance, using good rings with correct end gap, matching piston weights. Performance engineering 2stroke tuning we specialise in honda 2strokes, covering the cr range of motorcross bikes, the nsr250 street bikes, and hrc grand prix 125, 250, and 500s. The website does not intend to compeed with any other website dealing with 2stroke tuning, and the information shared is not at all as thorough as what you can get from reading the books. 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. Motorcycle tuning twostroke 1994 edition open library. Graham bell second edition this is the moped performance tuning bible as far as im concerned. Graham bell starts off by saying that he doesnt believe port time area and its all about the duration the ports are open.
Tile cable should route through the center of the headstay brackets. The way a two stroke motor works causes them to be f. Lets journey back to 1973 and read the book that was the two stroke bible of that era. Bigger carburetors, higher compression ratios, altered port. Those of us who have grown up in the japanese twostroke. Clean the air filter sounds stupid, but you can be sure there are a lot of bikes at the races with expensive racing parts and a dirty air filter. Two stroke performance 25 torca terrace, mornington, victoria 3931 rated 4.
The book covers the twostroke engine, its parts, its tests, its operation, its phases, its uses and the auxiliary equipment with it. It covers my early days in the motorcycle trade, on to starting my own mc business then forming my tuning business. In 1992 both the n2 and f2 models were replaced by the new. Turbo and even supercharger setups of various configurations can be very useful, however, they are often more complicated with 2 stroke tuning than with 4 stroke applications on a tangent, i did witness a 50cc turbo 2 stroke bike that would do over 150mph, but i digress. Twostroke carbs are usually found on leaf blowers, motorized bikes and mopeds. Overview there are many manuals and resources that offer tuning info for mikuni roundslide carbs, but most lack real world explanations of how to do the proper preparation along with that tuning. A reference book for the enthusiast engine tuner and race engine builder. The power listed on this guide is from experience not claims. Using the throttle, keep the engine at a low rpm, just above stall rpm. There is a huge interest in vintage snowmobiles and their simple two stroke power plants of yesteryear.
Twostroke high performance engine design and tuning. Legend boucles bastogne 2020 historic oldtimer rallye best scenes of epic race cars duration. The piston crown opens and closes the exhaust and transfer ports. Twostroke carburetors are perfect practice for novice mechanics. They are so simple and fun that ive always enjoyed tinkering with them. It covers history, physics, engineering and practicum for the development and refinement of high performance two stroke engines.
Detailed modifications and improvements are described. 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. Checking and tuning the mitures of a single cylinder 2 stroke. An excellent academic book on the theory behind performance tuning for 2stroke motorcycles. Thought i would show how to check that your 2 stroke is running right and to explain how you would change the mixtures to get the engine running right. The morbidelli 125 twin road racer is a rotary valve engine. 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. Improper tuning of your carb will definitely lead to lagging. The high performance 2stroke engine is a pulse resonance engine which means that the operation in general and the scavenging in particular is not only dependent upon the pulses created from piston pumping but also from combustion. They are easy to work with and do not require excessive motor knowledge to achieve desired engine performance. Fully revised with the latest information on all areas of engine operation, from air and fuel, through carburation, ignition, cylinders, porting, reed and rotary valves, and exhaust systems to cooling. Most of what i have read gives a full throttle mixture of around 0. Loads of equations, fairly modern information, and an easy enough read for the mechanics out there who just now how to make there engines run, rather then how to make them better then when they came out of the factory.
Graham bell steers you through the various modifications that can be made to coax maximum useable power output and mechanical reliability from your twostroke. The first issue to address is jetting and carburettor tuning. The most common mistake is to choose the wrong combination of engine components, making the engine run worse than stock. During the 1970s, we were the techs responsible for the jetting of countless aftermarket carbs for much of the offroad and road. A myriad of different aftermarket accessories is available for you to custom tune your bike to better suit your needs. New material on electronic fuel injection and computerized. Undoubtedly, the virtue which has most contributed to the widespread use and varied application of the twostroke engine is its mechanical simplicity. I am very proud of the riders i helped and sponsored and there is an appendix. The yamaha rd350 f2 was an updated version of the yamaha rd350 f faired ypvs model. Two stroke performance engineering service mornington. Scarce title on twostroke engines written by cesare rossaglia, a designer of both highperformance and racing engines.
Jennings book talks about port time area and porting the cylinder to have peak efficiency at a certain rpm. Great book for those of us who like to really get nitty gritty with their engine tuning. I think this book is the best book for 2 stroke engine builders and tuners to start out with. Twostroke performance tuning in theory and practice. These kits replace your cylinder and piston with a larger bore. Generally, you will also need to rejet your carburetor to allow a greater volume of fuelair mixture to enter your. Motorcycle tuning 4 stroke, second edition robinson, john on. There is quite a large section on changing the face of production racing and into the marlboro series and the lc era and through the kr1s and rgv eras. Basic 2 stroke tuning changing the power band of your dirt bike engine is simple when you know the basics.
But these changes will increase the power only if you know what you are doing. If youve ever thought about futzing with the port timing of your scooters one cylinder engine or making your own performance exhaust for your dirtbike or tuning the carb on your go kart, this book is for you. His port time equations dont even include rpm, you input the dime. 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. 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. Tuning and jetting honda, ktm, kawasaki, yamaha, suzuki, husaberg, husqvarna, tm, gas gas. Processors with a lower number of cores will run the motax expansion chamber. For sheer power for money and driveability the best setup would comprise of. Two stroke engine porting, head mods and pipes two stroke tuning advice from the experts at bimotion. Geared specifically for gp and kart racers, this hardcover treasure has turned out to be a great reference source for questions on the logic and concepts that pertain to tuning a 2stroke for maximum performance. Other books to his credit are modern engine tuning, twostroke performance tuning and forced induction performance tuning. I do not profess to be an expert on two stroke tuning, but i can give you my experience with a efi two stroke project i have been involved with for quite a while.
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