What is the best cleaner to clean motorcycle carborator

You have something assembled wrongly. Get a local mechanic to have a look see.

You will need some carb cleaner in an aerosol, and access to an airline to blow out any debris. If you have never done this before, carbs have lots of small parts and you may need a knowledgeable pal to look over your shoulder the first time.
When you use a blow gun wear eye protection!!

might be a problem with the electric choke sitting on the carburetor.
-or you should adjust the air/fuel ratio & idle speed settings on the carb (by a Vespa-shop)

most likely carbulator related , but i would try gas first , pick up some fuel cleaner preferably when bike is on e , pour in tank , and turn bike on , throttle it down with just the fuel treatment to really clean it out , if problem still persist check the choke on the carborator it may be to open causing a choke out as well

FIND THE FUEL SHUT OFF VALVE.IF IT WAS CLOSED WHEN YOU HAD IT RUNNING,THE FIX IS AS SIMPLE AS DRAIN OLD FUEL,REPLACE WITH FRESH GASOLINE,OPEN THE VALVE TRY TO CRANK IT AGAIN.
IF IT WAS OPEN WHEN IT WAS RUNNING,SOUR GASOLINE AND VARNISH HAS LIKLEY GOT TO THE CARBORATOR.
REMOVE THE AIR FILTER,LOCATE THE BOLT IN THE CENTER,ON THE BOTTOM OF THE CARBORATOR BOWL AND REMOVE IT. CAREFULLY EASE THE BOWL STRAIT DOWN,AS NOT TO BEND THE TAB THAT CONTROLS THE FLOAT LEVEL,OR LOSE THE FUEL INLET JET. EXAMIN THE BOWL FOR CORROSION OR GUNK.
THIS IS AN INDICATION THE CARBORATOR MAY BE PLUGED WITH GUNK,WHICH COMES FROM GASOLINE SOURING AND TURNING TO VARNISH AS IT EVAPORATES OVER TIME.
ON THE CARBORATOR,WHERE THE BOWL WAS TAKEN OFF,IN THE CENTER ON THE BOTTOM NOTICE THE FUEL PICK UP TUBE,TAKE A PIPE CLEANER AND CLEAN IT BY PUSHING STRAIT UP AND DOWN A FEW TIMES,THEN FLUSH IT WITH CARB CLEANER.
REPEAT THIS UNTIL IT IS CLEAR.
LOOK CLOSELY AT THE SIDE OF THE PICK UP TUBE FOR A VERY SMALL HOLE,WITH A SMALL WIRE,CLEAR THE HOLE AND FLUSH WITH CARB CLEANER.
CAREFULLY REPLACE THE BOWL AS NOT TO BEND THE TAB ON THE FLOAT,MAKE SURE THE NEEDLE JET IS IN THE NEEDLE SEAT AS YOU PUSH THE BOWL INTO PLACE.
PUT THE BOWL BOLT BACK IN,CAREFUL NOT TO OVER TIGHTEN IT.
WITH FRESH GASOLINE IN THE TANK,AND THE FUEL VALVE OPEN,YOU ARE READY TO TRY CRANKING IT.
IT MAY TAKE A FEW TRYS.
IF YOU FEEL CLEANING THE FUEL SYSTEM IS TOO MUCH FOR YOU,PLEASE DO NOT ATTEMPT THIS.TAKE THE MACHINE TO A SMALL ENGINE MECHANIC.
YOU MAY CAUSE COSTLY DAMAGE TO DELICATE PARTS OR UNINTENTIONALLY CHANGE THE FLOAT LEVEL CAUSING FLOODING OR STARVING OF FUEL TO THE ENGINE.
BEST OF LUCK...

The slow circuit of your carburetors is dirty or plugged. Take the carbs apart and squirt carb cleaner through the slow jets and the carb bodies. Count the turns in on your air screws, pull them and squirt cleaner through those passage ways too. Be sure to carefully remove, clean and inspect the carb tops too.When everything is clean and in good shape the bike should run great.

low compression

Were the carbs leaking before you took them apart?
try this use a rugger mallet of the hadle of a hammer and rap on the carb body to jar the carbs some times after rebuilding the carbs the float has not reacted to the fuel level. or you missed something in replacing the needle seat. If the carbs where gummed up from old fuel the little plunger on the float needle may be stuck it should move freely check it if its stuck soak it in carb cleaner you may need to take small needle nose pliers and grab it and give it a little twist to fee it be careful don't chew it up then soak it work it a few times.
Hope this helps

your carb. is gummed up. Get some carbeurator cleaner spray and spray it into the air intake as it is running until it clears up. if it wont clear up, you will have to have the carb rebuilt.

yes clean it with carb cleaner, take it off and take it all apart, every last piece and put it back together, it'll have trouble starting the first few pull but itll go