need to get my scooter running,?

i put a new carb, on my scooter i put new gas mix in. i try to start it .it allmost starts but wont stay running.i messed with the adjustment screw on the carb, now i dont know where a good spot is for the screw  to be.to get it to run.and what should the sparkplug gap be??

Andsetinn4 years ago
Quercus advice is good. All I can add to it is to gap the spark plug to just under 1 millimeter (if you'd rather use the metric than the illogical standard system). Google your carb and try to find a manual that gives you all the information. 2 turns out is good starting point. Sometimes the adjustment screws is supposed to sit flush with the carb when in factory default position.

The best website I have found for scooter setup and tuning information is 49ccscoot.proboards.com
Spark plug gap is probably around 0.034. Check with manufacturer for actual gap. If you cannot find what the gap should be, adjust for the strongest, closest to blue spark, possible. Take the plug out and gap to 0.034, and reattach to plug wire. Lay plug on engine case so the metal that the threads are on touches metal on the engine. Give it a spin with whatever method you use to start the engine. Check the spark and adjust accordingly. *Make sure all metal contacts in the spark plug path are clean and free of any rust/corrosion.* When you are satisfied with the quality of the spark, measure that gap and write it down for future reference.

*Most* small engine carbs are simple and use only air bleed adjustment screws. The basics for this adjustment are to turn it all the way in until it stops. DO NOT crank it shut tightly, stop turning when it hits bottom. Then open it back up 1-2 turns. Start the engine and adjust for idle quality. Each engine is different and may require different idle settings. Best I can advise you on is to get it to idle easily, but not fast. Once you achieve that, try riding it. Make adjustments to see what works best. When you finally get it to where you want it, turn it all the way back in, counting the turns, Write that down next to the spark plug gap and then turn the screw back to where it was (the appropriate number of turns). You should be good to go.