There was the established common knowledge about the carburetor parts of motorbikes : Pilotjets always controle only low speed area, mainjets high speed ares, and jetneedles middle.
We repeated the tests with our chassis dynamometer under many conditions in order to develop the new power full fuel control parts. We found that such common knowledge is not correct.
We would like to explain our right theory here by comparing the bike and their carburetor parts to a theater ply. In the drama of "Motorbike",pilotjets play the major role on the low speed scene and other actors (mainjets and jetneedles) play supporting roles. On another speed scenes,major role change to supporting role alternately. Even on the maximum speed scene,pilotjets play some role.
Main jet and jetneedle also influence all ranges of the speed.
So , if you want to get proper Air/Fuel mixture ratio (A/F) in the wide speed range,it is very difficult to achieve it with traditional carburetor parts.
KEYSTER combines three kinds of fuel adjustment parts, (pilotjets, mainjets and jetneedles), and developed new method to control A/F all over the speed ranges.
This is our new carburetor kit "Keyster".
Now we would expiain "Keyster" method with some examples.These technology may be surprise you.
In the low speed areas,you can turn up A/F a little with pilotjets "L" or jetneedles "L". If you want to increase A/F much more,you must use pilotjets "L" and jetneedles "L". By mainjets "L" or LL", you will get emphasize the effects.
In the case that you need turn down A/F, each fuel adjustment parts must be selected from "R" or "RR". (Usually, to decrease A/F by 1 in the low speed areas,you can achieve it by adjusting the idle screw. So,"Keyster" does not contain pilotjets "R")
From middle speed to full speed,"Keyster" is very useful to adjust A/F also.
We show A/F KAIZEN Maps in the developed illustrations. These maps advise you to the A/F adjustment ranges of each fuel adjustment part. Especially important theory that KEYSTER discovered is A/F adjusting effects can be added by the combination use of our mainjets and jetneedles. For example,if you use a mainjet that decreases A/F by 1 together with a jetneedle that decreses A/F by 1, your bike's mixchure decrease about A/F by 2. This admirable technologies is also under application for the patent.
There are a lot of carburetor kits,carburetor parts sets and carburetor jetsets in the worrd. However,only our "Keyster" can prospect the results of A/F adjustments.
Only KEYSTER can design all fuel adjustment parts easily.
Only KEYSTER can pruduce all fuel adjustment parts freely.
Only KEYSTER can fully test all fuel ajdustment parts with our chassis dynamometer.
Use our "Keyster".

Environmental management system.
Acquisition of  ISO international standards.
EMS 581432 / ISO 14001 : 2004

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