Carburetor Tips

Re-Installing the Carbs

The easiest way to reinstall the carbs is to spray the inside of the boots first real good with WD-40. Then the carbs will just pop right in, no help needed, no swear words. Works like a charm.


Synchronizing the Carburetors

Synchronizing the carburetors is easier than you think and very effective at improving the performance, efficiency and ride.

You can buy a simple mercury synchronizer (2-foot tall 4-tube "stick" filled with mercury) for around $40 - about what your local cycle shop will charge you for a single synch visit.

Synchronizing the carbs should be the last thing you do as a part of a tune-up.

Here's the process for synchronizing your carbs.

Before you begin, make sure the bike is warmed up first to normal operating temperature. Shut off the bike and proceed as follows:

1.     Remove the vacuum caps from the #1 and # 2 carb on the manifold side of the carb.

2.     Connect the mercury sync tool lines to carb #1-#2 where the vacuum caps were disconnected.

3.     Start the bike and let it run for a bit until it reaches normal operating temp again. Only run the bike at idle while warming up. *DO NOT REV THE MOTOR* you may suck the mercury from your synchronizer back into the engine.

4.  If the carbs are synched at this point (all columns of Mercury are even) then you are done. Otherwise use the following procedure to even out the columns:

1.     First sync carb #1 from above using the silver, slotted screw on the throttle linkage, halfway between the manifold for the two carbs (carbs #1 & #2). Turn the screw until the mercury columns for carbs #1 & #2 are even (within 1 cm). The adjusting screw will change the reading in one of the two columns - the goal isn't to get the columns to some specific height, it's to get them all even.

5.  Once all mercury columns are even, the carbs are synchronized. Re-adjust your idle (if necessary) and make sure that the carbs are stilled synchronized.

6.  Remove the hoses from the carbs and re-install the vacuum caps. I recommend holding the vacuum caps in place with tie wraps.

7.  Ride