My experience with the Jet-Tech software. By Alan Rees-Reynolds I have had the pleasure of testing for some time now. I did intend to do a back to back comparison of the other jetting products available but I met with some reluctance from the other software vendors. You may draw your own conclusions as to the reason for that by the time you reach the end of my article but I will say that I have tested the others so I do have knowledge of them, I just haven’t included them in the review. The first thing you realise when talking to John is that he is passionate about his product.

I deal with students with learning difficulties so I like products to be fool proof, so that if I try and be as awkward as possible with something and it still works, then practically anyone can use it. Jet-Tech is such a product. There are helpful notes available on screen to guide you through the various stages towards obtaining the correct settings on your carburettor. If all else fails, you can rely on John to talk you through calmly and easily over the telephone or by E-mail.

Included with the basic product is a section for the setting up of different carburettors other than the Dellorto, so whether you have a Tillotson or a Walbro or something else on your engine, help is at hand. Also included is information on gear ratios and conversion tables for fluids etc.; also included is a section on tyre temperature analysis. A section for recording your chassis setup and weight distribution is another aid for the karter that is included. My only small criticism with the help files is that you cannot print them out and refer to them as you negotiate your way around the screens, but it is a minor point and it can be got around if you know how.

For each setup, the following carb values are given: main jet, emulsion tube, needle type and clip position, inner pilot jet (iddle diffuser) and outer pilot jet (iddle jet).

However there is a built-in notes feature which allows you to make you’re your notes / testing diary at the track which you can print out on your return home. Much of the information you would need at the track can be found on the CD. How the software works.

The most essential thing you need to go with the software is a weather station that has barometric pressure and humidity include in its functions. These are available from or from the Internet. Once you have set up and calibrated your weather station for your height above sea level your weather station data is ready to be entered into the software. This gives you a starting point for jet size and needle settings. The thing to remember is that no software can give you the absolute correct information instantly.

Engines vary and carburettors vary, so to arrive at the ideal setting, you have to work a little bit. It is this work that suddenly makes the penny drop and you understand what you are doing and more importantly, WHY.

That is where John’s little sliders on the screen come into play. Those mystical phrases like Air Density etc start to become apparent and have some meaning. By reading the help files and notes, you begin to understand exactly what the problem is with the Max and more importantly, how to resolve it! You will find yourself saying things like, “Oh is that what that’s for, now I understand”. Once you have got it right, the software allows you to save all your hard work and be ready to jet up the next time you are at the track without starting from scratch again. Just as soon as you input your weather station data, the software presents you with your jet and needle settings.

The amazing thing about John’s product is just the sheer amount of work he put into its development and continues to do so. It is not just a glorified Excel spread sheet. It is a lesson in getting you to understand carburetion. He has included not just the normal float, jet and needle options, but you will find settings for needle types etc that you never even knew existed, such is the comprehensive nature of the product. If you run ‘non MSA’ then you can also use half clip needle positions by using a washer under the circlip, as the software allows adjustments of such small increments.

This allows you to get between those stages from one jet size to the next, more accurately. Hitting that ‘sweet spot’ where your engine sings sweetly and pulls through the rev range without that annoying popping or bogging is very satisfying. Just remember that all the other bits on your engine like the power valve, pulse pump, reed block and exhaust have to be in good working order to get the best from this product. You will also learn how to read your plug and piston crown colour and to look at the exhaust header colour and interpret what is going on in the engine. How many times have you heard people say that they only run the 168 jet size that came with their engine and it goes alright? Sure it goes, but only when the weather exactly matches the conditions for running a 168 jet, which isn’t often. Dop soglashenie o zamene tovara obrazec e.