Carburetor tuning Vespa GT 125

Hey Dave,
thought I answered this already,,,??? Classic "brass kit" symptom! >>> You need a "brass kit".. this is the needle jet and the jet needle in the center of the carb. The jet needle is the thin needle that hangs down from the center of the slide... The needle jet is the "hole" that the jet needle slides into...Remove the carb, take the bowl off, remove the main jet, the needle jet holder should be able to be gently tapped out, the needle jet is a short brasspiece,, it comes out through the hole where the slide goes,,, reinstall the NEW needle jet, needle jet holder...(it may have a groove in it for correct location). once its seated, you can reinstall the main jet..NOW >> to install a new jet needle,,, remove the slide from the carb.. remove the spring and seat from the slide that holds the needle jet in place.. NOTE which groove the clip is in on the old needle.... (should be the middle one). re install the new needle, reinstall everything else and your atv WILL run fine for a long time..This is a common problem on ATV's..
you need part #'s
1990 Kawasaki BAYOU 300 4X4 KLF300 C2 Carburetor

http://www.kawasakipartshouse.com/oemparts/p/kawasaki/16009-1503/needle-jet-n36w

http://www.kawasakipartshouse.com/oemparts/p/kawasaki/16017-1270/jet-needle-6

hi,,your carb wont do...its not big enuf airflow..but .the main jet for a vxr200 is a 1.18 or 1.20 (the 125 main jet is a 1.07).
i am haveing the same probs with a vrx 200 i bought..they run fine up 65mph & then seem to run out of fule...but chime back in when drops below 65mph..i have put the bigger main jet in & it doesnt make no diffrance..the carb carnt get enuf air to go above 65mph..carb of a 180-200 will sort it out but it may still need rejeting to suit big bore kit!!....also there is the carb of the dna 180 scooter as well.....good look..Howard

The idle circuit is plugged up. ALWAYS have a fire extinguisher on hand when working on carburetors.
Remove the water trap bowl at the bottom of the petcock, (gas valve). Is there any water or trash in the bowl? Drain a cup of gas from the tank. Is there any water or trash in the cup? Dump it, clean it and re-mount it, ( not all bikes have a water trap bowl ).

Drain the carburetor and remove the carburetor from the engine. Remove the float bowl and clean the entire carb with a spray carb cleaner from the auto parts store. Wear protective goggles to avoid getting spray in your eyes. Spray into all the little airways and fittings in the carb. Remove the idle screw and the air screw on the outside throat of the carb and spray into the screw holes as well. Pay special attention to the pilot jet area.
< < READ CLOSELY > >
Be sure to put these two screws back in the same hole they came out of. IMPORTANT > do not tighten these two adjusters down. Only screw these in until they LIGHTLY seat. Now turn each adjuster one and one half turns outward. Put the rest of the carb back together, clean the air filter and install the carb. Let the float bowl fill then start the engine. This process should get you back on the road. A “very helpful” rating for this answer? Thanks!

Remove the float bowl and clean the entire carb with a spray carb cleaner from the auto parts store. Wear protective goggles to avoid getting spray in your eyes. Spray into all the little airways and fittings in the carb. Remove the idle screw and the air screw on the outside throat of the carb and spray into the screw holes as well.
< < READ CLOSELY > >
Be sure to put these two screws back in the same hole they came out of. IMPORTANT > do not tighten these two adjusters down. Only screw these in until they LIGHTLY seat. Now turn each adjuster one and one half turns outward. Put the rest of the carb back together, clean the air filter and install the carb.

The stock main jet is #165. The number is stamped on the side of the jet. A richer jet would be #168. A leaner jet would be #162. Play with jet sizes to get the best overall performance at mid- range to high speed.
Can I get a “very helpful” rating on this answer?

Hello

>>The Following is an Instruction File I made for Correcting this Problem. Any Input is Appreciated.
>>****All the Carburetor Adjustments are the Same for Lawn Mower and Trimmers.
>>There are Several Location for the Air Mixture Screws.
>>The Idle Air Mixture Screws are Usually Located at the Top of the Carburetor Bowl and the Top of the Carburetor Body.
>>If the Main Air and Idle Air Mixture Screws are Side by Side on the Side of the Carburetor, then the Idle Air is the Nearest to the Engine.
>>The Main Jet Air Mixture Screw is Located in the Bottom of the Carburetor Bowl or Beside the Idle Air Screw on the Side of the Carburetor Body.
>>The Engine Idle Screw is Usually Easy to Identify because you can See where it Makes Contact with the Carburetor Throttle Shaft Plate Stop Ear. The H and L Air Mixture Screws Go Into the Body of the Carburetor and the Tips Cannot be Seen.
>>Some of the Older Model Carburetors have the Main Jet Mixture Screw Straight in from the Top of the Carburetor Body (this is Rare anymore).
>>If you have Cleaned the Carburetor (Disassembled and Soaked Overnight in Carburetor Cleaner (I Use Gunk). Then Blow Out the Passages with Compressed Air and Install a New Kit if Required.
>>Now Setting the Air Mixture Screws:
>>****Turn the Idle Air and Main Air Mixture Screws In Until SNUG **Do Not Jam** Then Reverse Both Screws 1 1/2 Turns.****
>>Holding the Throttle Full Open, Start the Engine.
>>Turn the Main Air Mixture Screw Clockwise Until Proper Revs are Obtained. Occasionally you May have to Turn this Counter Clockwise to Achieve the Proper Revs. Now Allow the Engine to Idle.
>>Set the Engine Idle Screw (Not Idle Air) so the Engine will Stay Running if Required.
>>Now Set the Idle Air Mixture Screw so there is No Hesitation when Throttling from Idle to Full Throttle.
>>Reset the Engine Idle if Required. If This Carburetor has a Single Air Adjustment.
>>Use the Section Above that Pertains to Full Throttle RPM Air Mixture Screw and then Adjust the Screw if Required to Eliminate Any Hesitation when Rapidly Throttling from Idle to Full Throttle.**
>>1- http://www.repairfaq.org/samnew/lmfaq/lmclctc.htm
>>2- http://www.cpdonline.com/692509.pdf .
Please, Do Not Hesitate, If you Hit a Snag or this Does Not Correct the Problem, I am Here if You Require More Assistance.
Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Be Safe and Be Happy. Thanks.

Good Luck

Respectfully

jbridger (John)