Modern Buddy

It started out with slightly difficult starting right after a fill up. Once it got down to half it started and ran fine. Now after 10 days of sitting it was difficult to start and was missing, sputtering, and surging. Had to turn around and take the car. Any ideas? Please include location of any items that you mention. I'm a newbie and don't know where anything is but the battery.
Thanks

First place I would look is the carburetor (directly under the seat bucket). Take it off, give it a good cleaning.

Have you had your valves adjusted anytime recently?

I am going to say that it has something to do with the gas that was used. It either had some sediment in it that has messed with the carburator, or it is just bad gas (old or had some water in it).

Number one, drain the old gas out of the tank. Number two, the carb needs a good cleaning. A new fuel filter should be used when putting things back together.

I had a spark plug boot crack and just not fit tight. Cheap and easy to replace if yours is damaged. Also had the carb come loose from the intake once, that I think was the prior owner just didnt snug it down. Also check battery terminals.

Just out of curiosity, is your bike stored inside? If not, maybe water got into the gas and into the carb? Either way, your carb is gonna have to come off and be thoroughly cleaned, paying special attention to both the main and idle jets.

And dont forget the dreaded stator! Depending on model, year and millage it could be taking a walk. I do agree with the bad gas suggestion, as the stator tends to fail on higher millage/older scoots. Any luck so far?

sc00ter wrote:And dont forget the dreaded stator! Depending on model, year and millage it could be taking a walk. I do agree with the bad gas suggestion, as the stator tends to fail on higher millage/older scoots. Any luck so far?

I had a stator go bad at 7,800 miles and another after 4,000 miles.

It doesn't sound like a stator to me though since it is "missing, sputtering, and surging." Be I might be wrong, stators can act differently as they start to fail.

If it was my scooter I would try to run a few tanks of gas through it as fast as possible, making sure not to overfill it. And a good dose of Seafoam wouldn't hurt. In the least I would run it 10+ miles to see if the problem clears up.

One thing you might want to do is open the air filter and see if there is any gas in there. If I fill my tank then park overnight and the temperature drops more than 30 degrees it will often dump gas from the carb into the airfilter. When this happens the scooter will be hard to start then will miss, sputter, and surge for 2-3 miles before it clears up.

Just fixed this problem on my buddy, needed can of carb cleaner, 10 mm socked wrench phillips screwdriver and some experience in taking apart a carb. good news is that i didn't have to totally remove carb. took off seat - 4 10 mm bolts . took off intake manifold from top of cyclinder head - 2 10mm nuts and washers , loosened two screws on intake tubes on each side of carb and pulled off fuel line at filter and a hoes on side of carb . rotated the carn to get the bowl off bottom, screws were real tight used a good fitting screw driver and vice grips for leverage. took out idle jet and it was clogged . soaked in cleaner and used fine wire to unclog, reassemble, watch out for o rings in carb bowl seal and one that goes between intake manifold tube and head. runs like a charm now