Need scooter help

[hnm3355]

hello every one i reacently got a 150 cc scooter with about 2k miles. i drove it home and drove it around a bit, but when i removed the carb and put it back it would just crank over.  im getting fuel by sucking on the vacum line from the tee to the fuel valve. also getting spark i tested it with a timing light.  so guys i need help can't figure out whats wrong since it was working before i removed it.

[Fox]

You sure you have all the lines installed back in the right place?

When I remove and replace a carb I always hook the fuel line up and suck on the vac. line for ten or twenty seconds to fill the carb up before I start cranking the engine to save the battery.

 Why did you remove it if it was working?

[hnm3355]

we had to install it into another scooter to see if it would start. i did (prime the carb)by sucking the vacuum line to fill the bowl


im going to get some carb cleaner to see if some how my carb got dirty with bad fuel from the second scooter.

[Fox]

That's weird. If it worked before and you didn't take it apart and change anything inside it then it should work now.   

[hnm3355]

yea it was just  a quick swap but im going to take it apart and clean it i think the other scooter had dirty fuel

[Fox]

That's the only real explanation. Something must have got in there and clogged the jets.

[hnm3355]

i went ahead and cleaned the carb out and i realised that using a timing light is not a good way to check for spark, the coil was bad , after swaping in another used one it fire up. but now it doesn't fire up right away like it used to. it take a few seconds and somtimes i have to give it full throttle and release as it is cracnking. 

[Fox]

Did you take out the idle mixture screw?

[hnm3355]

no i left that alone i didn't want to mess with that one, am i suposed to remove it.

[hnm3355]

i also didn't know how to proper;y set the throttle screw on my gauge its a 1.5k rpm but some people say that the back wheel should be turning slowly but its not do i ignore the gauge and just jump up the throttle screw.    ??

[Fox]

The idle should be set to a speed just below where the wheel spins.

Here's a guide for adjusting the carb:
http://www.scooterforumonline.com/index.php/topic,1603.msg7405.html#msg7405

The idle mixture screw meters the amount of fuel that is mixing with the air when the throttle is closed. Opening the screw allows more fuel. Basically you warm up the scooter for 5-10 minutes and then you turn the mixture screw to the left slowly until you hear the engine idle pick up. When I clean a carb I always remove the mixture screw and spray that passage out real good. having the idle mix right will make it start up easy and idle smooth. It also helps it transition from idle to open throttle better. No hesitation or "hiccups"

NOTE: There is an anti-vibration spring on the screw to keep it from turning. it will sometimes stay in the carb when you remove the screw. DON'T LOSE IT! I've have actually had to stretch the spring a little bit on a few occasions cause it was compressed so much it didn't do it's job.

[hnm3355]

thanks for the link i will have to adjust both of those after i clean the mixture screw. im about to order performance coil, cdi, new rear tire and a few other things hopfully then i can get my scooter rolling properly

[hnm3355]

well i just orderd new coil cdi , plug aswell as some new studs and exhaust bolts, i went ahead and and opened up the air/fuel mixture but my scooter still boggs down around 7k rpm and the speedometer says "80"kph the first time i drove it home that little needle would pegg out at 100kph. so im a bit stumped.    also another issue is that when i set the idle screw to were the rear tire berly wants to turn its at to high of an rpm so i just backed it down a bit not sure if thats the problem?   thanks for the help fox, i have the same scooter you do but in black.

[Fox]

Check for any cracks in the rubber intake boot.  Also check for cracks in the carb diaphragm.

 Did you change the air filter? If so, that might be the problem. Those aftermarket filters let in more air so you have to increase the size of the main jet to compensate.

[hnm3355]

Check for any cracks in the rubber intake boot.  Also check for cracks in the carb diaphragm.

 Did you change the air filter? If so, that might be the problem. Those aftermarket filters let in more air so you have to increase the size of the main jet to compensate.

diapharm was good and i didn't replace the airfilter, i did remove it to inspected it so i check to see if its loose inside or something