Adjusting Carbs

External Since: Jun 26, 2003 Posts: 4

I've got a XL125S with a non-CV carb. I just installed a rebuild kit
which I assumed used all the stock specifications. It runs now but
when I give it gas it bogs down a little and then takes off.
Mid-range and high-end throttle response are fine. This does not
happen with the choke on.

On a CV carb this behaviour is caused by the floats adjusted to low,
right? Is this the same on a non-CV carb? Before I start tinkering I
would like some "expert" advice.

Thanks

External Since: Oct 23, 2003 Posts: 76

DeZ <dez RemoveThis @cba.com> wrote in message news:<i7fkkv80jffqoloj1js7nl0k5vftd39upb RemoveThis @4ax.com>...
> I've got a XL125S with a non-CV carb. I just installed a rebuild kit
> which I assumed used all the stock specifications. It runs now but
> when I give it gas it bogs down a little and then takes off.
> Mid-range and high-end throttle response are fine. This does not
> happen with the choke on.
>
> On a CV carb this behaviour is caused by the floats adjusted to low,
> right? Is this the same on a non-CV carb? Before I start tinkering I
> would like some "expert" advice.
>
> Thanks

I do not know of a single carburator (CV or not) that uses float adjustment
as a means to adjust the mixture. An improperly adjusted float will affect
the mixture, of course, but you are supposed to properly adjust the float
before adjusting any other part of the carburator.

Perhaps you mean "the needles adjusted too low," which may be the case
for the low-range mixture in a CV. Note that a rich mixture will also cause
a power loss. "Bogging" is often caused by an overly rich mixture, but
you need to check. Running lean can cause problems so quickly that you
don't want to lean out the carb to test.

Did the carburator work fine before you took it apart, or was this problem
apparant before that? If the former, you may have dislodged some dirt and
gotten it where it does more harm than before. If the latter, it's possible
that the small ports didn't get cleaned properly, or that the carburator
was maladjusted before.

As for advice, run the engine for a few minutes, while trying to use the
slow jet circuit only. Simultaneousely release the clutch and turn off
the ignition, then coast to a stop and remove the spark plug. The plug
insulator knows all and tells all, if only you ask.