All
you are doing when balancing the carbs is trying to get all the
throttle valves to be in the same position when they open and close.
The
throttle valves are the gold coloured discs in the inlets of each carb,
as the throttle is twisted they open allowing more air into the motor
which also makes the slides/needles rise which allows more fuel into
the motor so if one throttle valve is open more than another more
fuel/air will go to that cylinder and it will try and run faster than
the others causing the engine to run rough and erratic and when the
throttle valves are all different the motor can really suffer, it’s
something that is often overlooked but it can cure many rough running,
clutch rattling, bad pickup and tickover problems
Note:
These carbs are from a FZR1000 and have the remote tick over
adjuster fitted this is not on the standard Fazer/FZX carbs.
The
choke lever from the FZX 750 carbs has been fitted because is a neater
set up than the plastic lever and cable used on the FZR 1000.
The numbers 1-2-3 refer to the adjusting screws that are used when balancing the carbs.
I am using the FZR 1000 carbs but the balancing procedure is exacly the same for the 700/750 carbs.
If
you have never done it before and want to have a go this is how it’s
done, you will of course need a carb balancer, I use the Carbtune II
synchronizer.
Balancing the carbs on the Fazer/FZX is an easy
job (compared to some bikes) get the motor warmed up so it runs without
choke and turn it off, remove the plastic covers that fit over the
little pipes on the inlet manifolds and push on the hoses from the
carbtune keeping them in order so the hose from the needle on the left
of the carbtune (call it number 1) goes to the far left hand cylinder
(number 1) and so on, start the motor and if your carbs are anything
like mine the carbtune needles will be all over the place!
Now you should have 2 pairs of needles (1 and 2 and 3 and 4) on the carbtune that are balanced but 1 & 2 will probably not be at the same level as 3 & 4 as in the photo below.&
Firstly, you balance one pair of carbs together, 1 & 2 or 3 & 4 it doesn’t matter which ones you do first, turning the number 1 adjusting screw (see photo above) will adjust carbs 1 and 2 turn it in or out until the needles for carbs 1 & 2 on the carbtune are level, when there ok do the same for carbs 3 & 4 using the number 2 adjusting screw until they are level.
2 will probably not be at the same level as 3 & 4 as in thoto below.
Now this is the good bit, using the number 3 adjuster turn it so the 2 pairs of needles come together until they are all the same level, you should hear the difference as the carbs come into balance and the motor smooths out, you might have to adjust the tickover once the carbs are balanced.
That’s about as good as it gets,
all four carbs balanced together :>)))
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