Engine stall when clutch lever depress while slowing down

Hi,

What will be the possible causes when clutch lever depress while slowing
down and engine stall ? This happens from occassionally (once or twice a
month) to every morning during the 10 minutes from starting. If engine left
idling after started in the morning, it will stall after 3 to 5 minute.
After that, Engine will back to normal.

Suzuki Maruader GZ125.

Any pointer is appreciated.

 

the 10 minutes from starting. If engine left idling after started > in
the morning, it will stall after 3 to 5 minute.

Stalling when you pull in the clutch to slow down usually indicates
that the idle mixture is too weak. You can tell the idle mixture is too
lean if the engine stalls when you pull the clutch in while slowing
down, or if the engine spits back through the carburetor when you open
the throttle. Also, lean mixture will cause little backfires out the
exhaust pipe when you slow down. The sound is fart-BANG!

You can make the idle mixture richer by using a slot screwdriver to
turn the idle mixture screw about 1/2 a turn counterclockwise. The idle
mixture screw may be located on top of the carburetor, between the
throttle butterfly and the engine, or it may be underneath the
carburetor in the same position. If you look at the carburetor and you
can't see the idle mixture screw at all, it's probably hidden by an
anti-tamper plug that must be carefully removed by drilling a small
pilot hole, screwing a small sheet metal screw into that hole and then
when the screw is pulled out with a pair of pliers you can see the idle
mixture screw. If the idle mixture screw is on top of the engine, you
can probably remove the plug without taking the carburetor off the
engine. But if the idle screw is underneath, the carburetor will have
to be removed.

If you turn the idle mixture screw too far counterclockwise, the idle
mixture will become too rich. The exhaust sound will be thudding and
dull, you may smell some unburned gasoline. But the engine will start
well and warm up fast...

Then, when the engine gets hot, the idle speed will be too high, the
engine won't slow down when you roll off the throttle...

You can tell if your idle mixture is too rich if you open the throttle
with the engine warmed up and the engine speeds up and doesn't return
immediately to the original idle speed.

You may have also have some dirt and rust in the fuel system or the
idle jets and idle passages are getting plugged up...

You can try cleaning out the fuel system by adding one ounce of xylene
and one ounce of acetone to a full tank of gasoline and riding the
motorcycle. This will clean gum and varnish out the carburetor. Repeat
the xylene/acetone treatment for three or four tanks of gasoline...