For Japanese Brand
Bikes
Carb
Synchronization
On most multi cylinder 4 stroke bikes the
carbs will eventually get “out of sync”.
The reasons for carbs to do this can vary but the results are
the same. Less power, bogging
at various rpms, and poor performance. Most obvious sign is the
lack of a steady idle point.
Your motor will rev high at times and want to die at other
times. This is due to your carbs
fighting one another.
We hope this tip on how to sync your own
carbs helps. Keep in mind bad jetting or a
damaged or “open” exhaust and electrical problems can cause
these problems too. You
should get professional advise on weather or not a carb sync
will work for you. I have
found a major difference in bikes I have synced.
First you must acquire a gasoline test
tank. This is a tank that can feed gas to your
carbs while your tank is off the bike. (note: a antifreeze
overflow tank from a water cooled
bike or car works nice. Most junk yards and bike shops have
these on hand). Also motion
pro makes one for 40-50.00 that has a petcock and fuel line.
Next you must acquire a set of
synchronizing gauges or sticks. The type I recommend
are the mercury filled type. They can be purchased for about
40.00.
Now, there are two basic types of carbs.
The two types are standard and CV (constant velocity).
Standard carbs will have a small cap on the top that must be
removed for you to sync them. The
CV carb ,usually on most all twins and most 4 cylinder bikes
after ‘79, are easier to sync due to
the fact that the adjustments are external.
The concept of syncing the carbs is to
make the carb work at its most efficient level with the vacuum
available to it. One off sync carb can drag down the rest of
the cylinders on power. So what you are
going to do is hook up a device (the carb synchronizer) to each
of your carbs vacuum tubes and adjust
the carbs until they are all working on the same vacuum level.
So here are the steps.
Now you should have a synchronized
set of carbs that will make your bike more powerful and
smoother than before.
If you have any questions about this procedure or where to
find the adjusters on your bike Feel free to call or e-mail
me.
SAFE HAPPY RIDING
Additional Information
Here is a link to a site about how to make the tool for YICS Yamaha's.
http://home.westman.wave.ca/~jbe/YICS.htm (non
functional link to save confusion.
You will need to cut and past to your browser to use) (You
will want to use the link below
to see the instructions in such a way that allows return
to our site) This is NOT our material.
It was copied from the link above. The actual tool is no
longer available from Yamaha.
This link could save you time and $ The link was
supplied by a customer that wanted to help.