Buddy 50 help: Chokes, backfires. Scooter shop is stumped..

[sugarshark]

I wrote a novel about my issues which is posted below but if you don't have time to read the short of it is that my 2008 Buddy 50 with 1,600KM on it is choking on me when I decelerate at a light/stop sign or turn a sharp corner. It runs but backfires when I give it gas and lurches forward a bit. It seems to work after waiting 15-30 mins sometimes and if it's choking/backfiring and I keep giving it gas, sometimes it clears up and will all of a sudden ride like normal with a burst of power like it's cleared something but it always chokes again on me and now it's unrideable. I've tried taking the gas cap off. Scooter shop says it's not fuel and compression is low. Might be an air leak or pistons but they are stumped. I thought it might be the stator but they say no. Any ideas?



I bought a brand new Buddy 50 in 2008 from the local scooter shop who was fairly new then. I was really excited when they opened up as I'd wanted a scooter for years and we didn't have any scooter-only shops in my city.
I picked up my scooter and they told me to keep it under 50km/h for the first 300 km and bring it in for it's first service. Everything was fine and I rode it to it's 1000km service. Then things started to go wrong. I asked what I could do to get more power on hills since there are a few on my route home and it was only going about 25-30km/h up them. They de-restricted it I believe at that point and said they would 'chop' the exhaust? I'm not sure what that means but I didn't notice anything different about it afterwards.
The next summer I took it in without riding it because I was afraid I put the wrong fuel stabilizer in it. I didn't know there were two different kinds so they said they would clean out the carb. I paid for 1.5hrs of service and went on my way. My scooter died on me when I came up to a merge and I coasted to a stop. It would not start so I had to take it home in my moms van. It started again later but kept dying so I brought it back in (maybe 5 days later?). I came to get it and they told me the carb was full of nasty gunk and they cleaned it out and presented me with a bill for an hour of service. I was choked and told them I already paid them for 1.5 hours to do the SAME SERVICE 5 days before! The guy said his boss would be pissed if they let me leave without paying and I argued with them for awhile and then he said ok, what are you willing to pay? I saw red and said NOTHING as I'd already overpaid for a service that wasn't even done. My bike also now had an oil leak that wasn't there before as well!! Then he told me that they had to fire their mechanic because he was crap and this is the guy that worked on my bike. Who knows what he did to it?
Anyway, it ran ok that summer but I only rode it a few times as I was away most of the time. This bike has 1,600 KM on it currently to clarify and this was at the 1000 KM mark. so I probably put on another 400 that summer. I took it out this year and it ran ok the first short ride. The second time I took it out it choked on me again while driving. I waited about 15 mins and it started up again and I was able to get it to my aunt's house that was nearby and then it died and wouldn't start at all, even after a few hours. I came back the next day and it started so I drove it home fine. I replaced the battery thinking that might be the issue and had a friend look at it who adjusted the idle which was always off and he said the gas lines were mixed up like the big one was where the small one should be a vice versa so he switched them. I figured that was the problem and took it for a ride where it ran great so I was happy. Took it into town a day later and it choked on me after I turned a corner. It would start and run but it would do these little backfires and it would go forwards even at full throttle. It would just run really rough and lurch forward a teeny bit. Gas was at 1/4 so I walked partway to the station and tried again and it fired up and went so I drove hard without stopping as this seems to make it die and made it. Filled up and it drove again to the coffee shop down the road. Waited for an hour and drove it most of the way home without stopping and as soon as I took a sharp corner and decelerated it choked on me again. Waited 15 and made it halfway up a small, steep hill and and had to push it up the rest of the way. Then waited 15 again, wouldn't work, waited another and finally got it home running really rough. Took it out one more time and it choked after not even 1km.
Decided to bring it in the same shop even though I had a horrible experience there. Now it's been in there for 5 days and they haven't called me once to update me. I called on saturday and they said it would be ready by 5:30 so I went down there to get it and it wasn't ready!! They were not apologetic at all and said they needed to keep it for another hour. They are closed sun/mon so I wait until today and call at 2:30pm and they tell me they have no idea what is wrong with it. They have ruled out fuel and say the compression is low so they think it's either an air leak or the pistons.

I am so frustrated with this place and this bike.

[jmkjr72]

a back fire on a 2 stroke means only one thing unburnt fuel is getting into the pipe
some unburnt fuel is nromal and shouldnd cause a back fire
reed valves that are not sealing is one way unburnt fuel would get in
poor spark is another

with that few km i doubt it would be low compresion
did they run a leak down test or no

honestyl i would start with looking at the plug and tell us what the spark plug looks like

[Keys]

I was just going to say it sounds like intermittent spark. Have the shop check wire continuity from the loom to the coil.

--Keys

[SteveK]

A faulty choke (enricher). Backfires are mostly caused by rich fuel mixture loading up in the pipe then exploding. Ask me how I know? Just had the same problem with a new Arreche carb I bought for my TPT 70cc BBK and RS-II pipe setup. The new carb had an intermittent choke problem and was just dumping rich fuel mix into the engine.

It's worth a look see. In your case it may just be partially unplugged causing the intermittent condition.

I went manual choke to be done with it.

Good luck.