This website and app will help you tune your moped or any two stroke engine. 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. I invested in a tuning software last year, bimotion, and made adjustments to the ports and made a pipe according to the instructions. We cover that, as well as other mods on a four stroke engine. We believe that using this software will help your 2stroke development or racing results on different types of competition. Graham bell is an acknowledged expert on engine tuning, with many years experience in this field. Two stroke cylinder porting tips watch this before you start cutting. Other books to his credit are modern engine tuning, twostroke performance tuning and forced induction performance tuning. Two stroke design instead you can enter the data of your cylinder with extreme facility and precision, and then analyze the port areas and the timing area in the engine cycle timing for each phase. Carburettor tuning for performance part 1 the challenge youtube. Good resources on cylinder porting and tuning in general include jennings two stroke tuners handbook, and two stroke performance tuning by a graham bell. Parts for scooters with morini 50cc 2stroke engines.
The 50cc 4 stroke engine, also known as qmb9 or gy6 50, is the most common engine used on small frame chinese scooters. Twostroke 2s scooters powered twowheeled vehicles with engine displacement. The power listed on this guide is from experience not claims. Motorcycle tuning twostroke 1994 edition open library. There are many ways to boost the power, one of which is by installing a tuned pipe. I am very proud of the riders i helped and sponsored and there is an appendix. An engines exhaust port can be thought of as a sound generator.
Tom turner, master two stroke tuner, pipe builder, and the man that developed tsr two stroke racing software designed and built his 424cc yamaha rd400 dragbike to develop and prove his racing design software and prove it. From the bellmouth of the carburetor, to the insert of the reed valve and the reed petals, at the studied of the cylinder ports, until to the balance of the crankshaft, thanks at our software you could optimize your engine and to. Twostroke engines do not use fuel efficiently, so you would get fewer miles per gallon. But because of the limited worldwide activity in two stroke engine development, program sales were limited and further development was curtailed. Aussie twostroke engine invention motorbike writer. It will simulate one of the cylinders of a multicylinder two stroke engine provided that the cylinders are identical in layout and dimensions and each cylinder has a seperate exhaust and induction system. This is in contrast to a fourstroke engine, which requires four strokes of the piston to complete a power cycle during two crankshaft revolutions. Saabsa saab twostroke engine swapped in motorcycle. Software for optimal setting and design of engines and. In doing so, then you can tweak the threepart formula to. No previous knowledge of the twostroke cycle engine is required just input the required data and then run mota to set in motion this powerful process. Pdf improving the performance of twostroke motorcycle with.
Checking and tuning the mitures of a single cylinder 2 stroke. They are so simple and fun that ive always enjoyed tinkering with them. How twostroke expansion chambers work, and why you should. Tuning a scooter can provide a noticeable boost in power if performed correctly, and it can be done inexpensively. The minarelli engine is a popular model of 50cc 2stroke engine and 90cc 2stroke engine that is found on taiwanese and chinese scooters. For the most part, there are two common, distinct applications of tune in motorcycle engine. The bike came alive as if it been in coma before i sounds more like a road racing engine now i also reworked the head from a second head program and the throttle response changed completly. This applies to motorcycle, car or automobile engines.
The basicexhaust tuning mechanisms was described w ith respect to a twostroke singlecylinder engine. Two stroke performance tuning twostroke all of these detonation triggers are virtually unavoidable, with the exception of excessive spark lead. Software for fine tuning and design of two stroke engine. Blair of queens university belfast, and published by the society of automotive engineers. 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. But because of the limited worldwide activity in twostroke engine development, program sales were limited and further development was curtailed.
You would burn about a gallon of oil every 1,000 miles if you used a twostroke engine in a car. Hi guys, need a little guidance on tuning a 70cc 2 stroke scooter. How twostroke expansion chambers work, and why you should care. After doing so the engine wouldnt rev beyond idle on the size 80 main jet. By using the torqsoft exhaust timearea programme, it was possible to raise the power output of the engine by 10% just by a simple modification to the exhaust port. 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. Find your two stroke scooter engine parts here for minarelli 50cc engines from yamati, eton, yamaha and many others. Racingsm software has some specific modules that can help tuners builders on their race engines bikes in order to improve performance and reduce lap times. On the other hand, while the twostroke engine does not commonly require large. Small 2stroke, 2249cc complete engines are commonly found on standup, chinese gas scooters, pocket bikes, minichoppers, small dirt bikes and atvs. But there has perhaps never been a more motorcyclelike car engine than the. Where did you get the moped shirt its very cool dude. For sheer power for money and driveability the best setup would comprise of. From the bellmouth of the carburetor, to the insert of the reed valve and the reed petals, at the studied of the cylinder ports, until to the balance of the crankshaft, thanks at our software you could optimize your engine and to develop new components to reach the best performance.
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. Engine geometry is modeled using commercial proe software. To tune a scooter, you need to understand the relationship between sufficient fuel flow, air intake, and how a combustion scooter engine works. Extreme motor sales 2 stroke scooter parts 2 stroke. A tool to tune your two stroke engine, calculate duration, time areas, etc. Twostroke oil is expensive, and you need about 4 ounces of it per gallon of gas. The information used in the programs calculations was taken from the books the basic design of the two stroke engine and the book design and simulation of two stroke engines. Moreover you can have advices for the development of the engine thanks to the help of tested formulas for intake, exhaust, blowdown and transfer. Use the throttle to slightly increase and decrease the rpm. When i initially start the scooter, it runs fine under wot. At one point, he pulled off the muffler and used a dremmel tool to remove the restricting ring and that sound deadening mesh. Twostroke engines produce a lot of pollution so much, in fact. This toolkit offers some basic two stroke engine calculators in hand but also extends to some advanced as well tuning menu. Pdf engine performance is strongly dependent on gas dynamic phenomena.
It covers early development work and since it was written in 1968, does not have any of the powerful twostrokes of the later period. That is how a twostroke engine completes a power cycle in only 360 degrees of. High performance parts plus shocks, brake parts and cosmetic parts. It covers my early days in the motorcycle trade, on to starting my own mc business then forming my tuning business. Tuned adjustableexhaust pipe for use on twostroke motorcycle was. Twostroke principles although a twostroke engine has less moving parts than a fourstroke engine, a twostroke is a complex engine because it relies on gas dynamics. For manufacter and tuner of two stroke engine, ntproject has developed a series of software to help in the development of the engine and its components. Two stroke cylinder porting tips watch this before you. The software does complete cycle simulation of the whole internal combustion process including the gasdynamics in the pipesducts, ports and plenums air boxes, boost bottles, exhaust boxes etc. 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.
These kits replace your cylinder and piston with a larger bore. On two stroke carburetors this is an air screw so dont forget turning the screw out is a leaner mixture. In contrast, a twostroke engines valve timing may be altered simply by reshaping the holes in its cylinders, and its power output markedly changed by utilizing inertia and resonant effects in its intake and exhaust tracts. 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. Graham bell steers you through the various modifications that can be made to coax maximum useable power output and mechanical. I would have to view it as a history book, but one that is necessary to any complete library of engine design. I take it to the end of the street and it starts to bog only when its pinned. Moreover you can have advices for the development of the engine thanks to the help of tested formulas for intake, exhaust. Test your own theories on porting and exhaust pipe design. A sydney engineering company has developed a new twostroke engine that they believe could be used in motorcycles. Build 2stroke exhausts, know how to change gear ratios depending on racetrack, simulate realworld performance with our bike dynamics simulator. You dont need fancy expensive stuff to port two stroke cylinders, you can get by with. It covers not only two stroke motorbike engines, but also car engines as well.
On a size 90 jet their is plenty of power however the engine and exhaust feel very hot. Its called crankcase independent twostroke cits and was invented by former south african motorsport engineer basil van rooyen, director of cits engineering, st ives he says advantages over fourstroke are that the cits engine is more powerful, lighter, smaller. Using the throttle, keep the engine at a low rpm, just above stall rpm. Two stroke moped tuning a tool to tune your two stroke. The newspaper hooniverse dedicated to the world of two wheels published an article definitely worth noting that we are sure will intrigue saab enthusiasts who love motorcycles there have been lots of bizarre accounts of bike engines swapped in cars, and car engines in bikes. Those of us who have grown up in the japanese twostroke. Motorcycles, maintenance and repair, motors twostroke cycle. Rating is available when the video has been rented. From a 49cc racing engine, to a gp 125 engine, or a 1500 mercurial triple engine, or a 250 kart engine, racingsm software suits all. Here we are tuning a yz80 motocross engine for use in a motorcycle road racer. Mota and its related set of programs have been developed to simulate the performance of highoutput single cylinder two stroke engines. My porting setup affordable and functional 2 stroke tuning.
Twostroke high performance engine design and tuning. The way a two stroke motor works causes them to be f. There are different phases taking place in the crankcase and in the cylinder bore at the same time. Generally, you will also need to rejet your carburetor to allow a greater volume of fuelair mixture to enter your. A twostroke or twocycle engine is a type of internal combustion engine which completes a power cycle with two strokes up and down movements of the piston during only one crankshaft revolution.