JETS-R-US: CARB SWAPPING CONVERSION
AND
CONVERSION FOR KEIHIN TO MIKUNI TO DYNOJET

Question, I am swapping a Keihin carb for a Mikuni carb, what jet do I use? The table below may give a place to start. For example lets suppose that a Mikuni carburetor has a size 100 main jet in it, the equivalent Keihin jet would be a 110. Therefore after the carb swap a "guesstimate" to start with would be a keihin 110 jet. The chart will not be a perfect match because there are many variables, for example, different carb flow characteristics, different needles, orifices etc. but it is a starting point.

Question, I have some dynojets and would like to purchase Jets R Us jets, how do I compare the size of your jets to dynojets? We do not sell dynojets. Dynojets as well as many other aftermarket jet manufacturers try to duplicate the original jets but they cannot. A simple example of this inability to copy a jet is they do not carry hex jets, only round, and you must use a main jet adapter. Dynojet cannot manufacture the internal lead in and exit taper and other important details that match the OEM jet. A dynojet is not an equivalent jet to the OEM jet. Because dynojets are not manufactured 100% the same as mikuni there is not an exact comparison between the two.

Question, how is the table below used? Example: 1) A Keihin carburetor has a dynojet 100 in it. The Keihin equivalent would be a 102. Example 2) A Mikuni carburetor has a dynojet 112 in it. The Mikuni equivalent would be a 105.

Note that Keihin jets cannot be placed in Mikuni carbs and vice versa.

The table below is an approximation, results in the carburetor will vary.

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