Buddy 50 sputtering on throttle

Celebrandir · Post by **Celebrandir** » Fri Mar 28, 2014 4:41 pm

I've been working on getting my 2009 Buddy 50 ready for spring and I've run through all the routine maintenance fixes but I'm still having a problem when I try to ride it out of the driveway. The scooter starts easily on electric-start or kick-start, idles well, and revs up when I apply the throttle while it's on the center-stand. But after a couple of minutes it'll start to idle lower and lower and then will sputter out. If I try to ride the scooter out of the driveway it won't get more than 100 feet before applying the throttle causes it to drop power down to a weak idle. If I apply the throttle very slowly it can rev up but if I apply throttle as normal to accelerate from a stop it will sputter. If I keep trying the throttle it will stall.

So far I've carried out the following work on it:

- Replaced the air box filter, applied air box oil to filter so it's damp but not wet
- Changed the gear oil, precisely measuring the new fill to match volume of old
- Replaced the spark plug and checked the gap to be correct
- Replaced the battery with a new one, fully charged with my battery tender
- Replaced the fuel filter
- Cleaned the carburetor, soaked the jets in carb cleaner until I can see light through both jet bores
- Filled tank with new fuel and treated fuel with sea foam
- Topped off oil supply in reservoir
- Adjusted the idle to as high as I can before the rear wheel spins
- Checked the mix screw but I can't open it more than a partial turn from its set point before fuel starts to dribble out the rubber exit tube at the base of the carburetor, so I kept it at the position where I found it

It seems like the problem is elsewhere, but I'm not sure where it's most likely I should look next. The scooter has plenty of electrical power, headlamp is bright and turn signals are strong, and it starts by push-button easily.

Maybe I need to replace the petcock? Or does this sound like something related to the stator? I don't really have much experience with all this; I'm basically teaching myself everything from the service manual and Youtube videos. Any suggestions? And thanks!

OldGuy · Post by **OldGuy** » Sat Mar 29, 2014 2:29 am

Sounds like it runs fie when the automatic choke is on, then not so good as the choke shuts off. I would suspect a clogged jet, especially the main jet. Have you added Seafoam? This may help clear it out.

Celebrandir · Post by **Celebrandir** » Sat Mar 29, 2014 2:46 am

Yes, I treated the gas tank with sea foam, and both the main jet and slow jet look clear, with light visible through both. I'd expected that to be the main problem, but cleaning out the carb and jets didn't help at all.

OldGuy · Post by **OldGuy** » Sat Mar 29, 2014 4:07 am

Does the main jet have very small holes along its sides (to atomize the fuel)? If so, are these clean also?

Celebrandir · Post by **Celebrandir** » Sat Mar 29, 2014 4:12 am

Yes, tiny lateral holes running along parallel to the narrow barrel of the slow jet, and they all look to be shiny clean.

zuki · Post by **zuki** » Sat Mar 29, 2014 4:43 am

how many miles are on it?

Celebrandir · Post by **Celebrandir** » Sat Mar 29, 2014 4:59 am

~4,500 miles so far. It's my primary vehicle outside the snow months.