I have a Kymco People 50cc scooter. It’s very nice but it’s been sitting outside unused for about a year, including a Colorado winter. It won’t start. A buddy of mine who fixes motorcycles told me it probably needs new spark plugs. The thing is, I can’t find a manual for this thing on the internet. Something that shows me whats inside of it and how to get in there and what all the parts are called. The thing appears to me to be a proprietary black hole. We only have one scooter dealer in town and I just know this guy is going to rip me off if I ask him to come pick it up and fix it. I want to do it on my own. How do I get started?
I have a PDF copy of the QMB-139 service manual. You’ve got the same engine that I have in my Kymco Sport 50. If you want a copy, drop me a line.
After years of owning scoots with this engine, I’m pretty much an expert on them. I’ve done it all from basic maintenance to a complete teardown and rebuild. Any questions not covered in the manual, feel free to ask.
Q.E.D.++ 
Its also worth mentioning that gasoline breaks down after a couple of months, so if there’s gas in there from last winter then you’ll need to drain the gas tank and bleed the fuel line and fuel filter too. Also your tires may have flat spots from sitting around, so be careful on it and decide whether they need replacing if the flat spots dont go away.
It’s not that I don’t believe you, just that I successfully started my lawnmower with age old gas the other day. What do you mean by breaks down?
I am starting to regret my neglect - its going to be a good deal of work. Should be fun though.
I took the unused for two years carnivorous plant generator to the shop, and it was diagnosed with “bad gas”.
Whatever that means. They changed the gas and charged me their minimum fee for being a dummy.
Its a crapshoot, sometimes the gas lasts and sometimes it doesnt. Gumminess, condensation, and seasonal formulations can cause a lot of issues. I would replace the gas, but its your bike.
I will replace the gas, thanks.
You’ll probably also want to pull and disassemble the carb. Clean everything off with Gumout, paying special attention to the various jets inside. Make sure the float valve mechanism moves freely and the valve itself isn’t stuck to the seat with varnish. Gasoline doesn’t “break down” in the normal sense of the term, but it does 1) get contaminated with water because gasoline is slightly hygroscopic and 2) it polymerizes over time, forming a gummy varnish. Modern fuel formulations have additives to help prevent this polymerization, but they don’t keep it fresh forever.