How To - Synchronize The Carburetors

Parts Needed, Tools Needed, What and How? Step-By-Step

Topic:                           Synchronizing wetbike/seaflash/jetstar carbs

Expertise Required:      Intermediate

Estimated Time:            CE Method (see below) takes about 10 minutes

                                    Using synchronizing tool takes about 15 minutes.

Parts Neeed:               You will need the following parts:

      • None really

Tools Needed:             You will need the following tools:

      • A fully quallified and/or certified CE (Calibrated Eyeball)
      • An electronic Synchronization Tool
      • A bubble-type Synchronization Tool


What and How?          There are 2 basic synchronizing techniques.

      • The first is best done using the "Butt Dyno". This involves use of the "Calibrated Eyeball" (CE) method to synchronize carbs. Easiest to do when you have the motor on the workbench and an unobstructed view of the carburetor shafts/flaps. Wipe off the CE and crack the throttle open approx. 1/2 way using the top-most carb linkage. Then, if your calibration shows that the lower carb isn't in the same position, then adjust it's position using the linkage. Be careful with these linkages and be sure you get the jam nut(s) tightened back securely.
      • The second involves using a Synchronization Tool. This procedure is similar except that you need to have the bike/boat/seaflash fully assembled and running in the water (to put a load on the motor).


      • Run it long enough to get it warmed up
      • Hook up sync tool and vary the throttle a bit to see how close they are at various rpms.
      • Adjust the linkage as necessary to get them to be equal through most of the lower rpm range (less than 1/2 throttle)
      • Tighten the linkage.
      • Don't forget to put the hoses back on the nipples - including the bottom one. Either use a plug to block it off (if you are using velocity stacks) - or plug the stock drainage hose from the airbox back on.


Joomla templates by a4joomla