Motorbikes need proper mixture gases to obtain nice engine performance. The condition of mixture gases is judged by Air/Fuel mixture ratio (A/F). The theoretical A/F is generally 14.8 and air-fuel mixture is preparated in carburetors.
However accordind to the condisions of engines or handling way of bike by riders,differet A/F is required. To make the matter worse,A/F of each motorbike changes gradually while the bike is being used for long time. Because of ①ageing of carburetors, ②changes of condition of airfilters or mufflers, ③looseness of joint parts.
Additionally, electrical matters and deterioration of engines complicate the troubles.Consequently, tune-ups of motorbikes are fairly hard work.

For repairment and tuning-up carburetors, many kinds of carburetor parts are on the market.
Especially, main-jet sets and pilot-jet sets are rich in size.
It is generally said that pilot jets adjust low speed areas and main jets adjust high RPM areas. Middle speed areas are mainly controlled by jetneedles. Howeve spare jetneedle sets are almost not on sale in the world. So we must change clip trenches of jetneedes and adjust A/F only within ±0.5 at maximum.
We use these carburetor parts and try tuning. However it is dificult to get satisfied in the result. why?
If we choice one size of the jets,we can't prospect how much A/F will be change. We must repeat try and error until find a proper jet making by accident. Only a few high skilled technicians can achieve this stage.

KEYSTER introduce a new product "NENCHO-KIT". This is a epoch-making carburetor kit.
"NENCHO-KIT" contains not only regular repair parts but also diverse fuel tune-up parts,such as needle valve,idle screw,float chamber gasket,etc,・・・・・・・・Rubber needle is famous AA-Needle.
AA means Anti-Alcohl. It has superior resistance against ethyl alcohol and methyl alcohol. Additionary,We won an invention award by this superior needle.
Especially important parts in "NENCHO-KIT" are 6 size mainjets, 3 size pilot jets and 4 size jetneedles.
6 size mainjet indicated LL, L, S, R, RR and RRR. S is standard size (original size).
L means "Lean" and R means "Rich". More "L"s means leaner air-fuel mixture (A/F become large) and more"R"s means richer(A/F become small).

A/F= LL > L > S > R > RR > RRR
(jet hole size= LL>L>S>R>RR>RRR)

3 size pilot jets are indicated in L, S and RR.
Each size of jet is showed in developed illustration.
Also KEYSTER can offer you such A/F cotrole set even with jetneedles.
4 size jetneedles are indicated L, S, R and RR.
Only KEYSTER can make these variations of jetneedles. Each size and angles is also showed in developed illustration.
You can flexibly control motorbike A/F with "NENCHO-KIT" fuel tune-up parts.
These superior technologies are under application for patent.

There are many kinds of jet sets in market. Without exception, they contains several sizes of jet with equal interval,such as 100,105,110,115・・・ etc. However, "NENCHO-KIT" is not contain equalinterval size jets. Our jet sets and jetneedle sets are very useful for ajust A/F effectively and precisely.

Try our "NENCHO-KIT".

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

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