Thursday, August 28, 2014

low carb

I spent most of my Saturday with my arms elbow deep in the bowels of a Chinese scooter. 


It was a cool day, so it wasn't the worst way to spend an afternoon.  It's amazing how much trouble that shiny silver carb cover was hiding. 

About two months ago, the scooter in question went to a shop to have the carb checked because it was flooding. It was fine for about two weeks, then earlier this week, it started flooding again. After work on Saturday, I opened it up, put a bit of carb cleaner in it, and it fired up and was puttering away nicely, then cut out. We loaded it in the back of my wife's car (it was at the home of one of my son's friends), and took it home. At home, a quick inspection revealed that, wonder of wonders, there was no gas in the tank, which is apparently a requirement of internal combustion engines. After the addition of fuel, the scooter again fired right up, and seemed to be idling fine. After a few minutes at idle though, it suddenly started to rev higher and higher, then cut out. Apparently this is what was happening when it was shredding belts a few years back, except in that case, the engine would rev so fast the belt would fly apart.

It would then start and run for a bit, then eventually flooded. I tinkered with this and that and since the carb has been worked on a few times and I have no idea how to competently take the thing apart so I just ordered a new one off Amazon for $25.00. It's a standard carb type and replacement parts are so cheap, it wasn't worth taking to someone for a rebuild. I figured it might take some tuning, but would be easier than trying to figure out what is wrong with the old one. I also ordered a new fuel petcock as it was one of the other possible causes of this revving issue, and for good measure ordered one of those snazzy little air filters to replace the crummy old airbox.


The parts arrived today and were waiting for me in the mailbox when I got home at six. After about an hour of unplugging this and that, replugging this and that, and mashing my knuckles into the scooter frame, the new carb was in place along with the replacement petcock.

A quick last check and I inserted the key into the ignition and hit the starter. The starter whirred and whirred as fuel slowly trickled down the transparent lines to the fuel filter. A few moments later, the engine chugged to life, sounding better than it ever has to my ears. The scooter ran for a good twenty minutes with no issues and idled at a regular rate.

So, yes, I still think Chinese scooters aren't for everyone, but with a bit of mechanical ability (and if I'm any measure to go by, it's not a whole lot), they can be repaired and maintained very inexpensively. Consider that my Kymco just had to go through inspection, and the bill for labor and parts came to $455.00. Compare that to this little 50cc with its simple engine and it's hard to argue that they aren't a viable alternative. I'm not certain I would rely on a China scoot as my sole transport; however, I will keep observing and continue to take in data.



7 comments:

kz1000st said...

Welcome to the world of Chinese scooters. A good way to prevent the carb issue is to use an ounce of Seafoam every other tank or so. You probably sucked glop into the carb when it ran out of fuel, setting the dominoes in motion. Every experienced Chinese scooter owner has Seafoam in his garage. I have two bottles.

Paul Smith said...

Yeah. I tried using carb cleaner after it started flooding but to no avail. New problem though, it blew another belt, but I have a hunch it blew because it had been through a lot of running at high revs. So I stand by my thoughts of secondary vehicle only.

kz1000st said...

What kind of belts are you using? www.partsforscooters.com has Gates Powerlink Premium, an aramid fiber belt, for that scooter. My belt on the 150 lasted 2400 on the original, 6,000 on the Gates Powerlink so far, and the CF Moto went 9,500 on the original Bando Kevlar. Even the Lance Charming 50cc had over 1,000 on the original. Belts don't just implode without a reason. Either they're really cheap, the clutch or the variator is malfunctioning or the vent for the case is clogged or blocked. I did an 80 mile ride with the 150 recently with the Gates belt. No problems. You might try running without the case cover on and see what happens.

kz1000st said...

Oh and Seafoam isn't just a carb cleaner. I'm not up on exactly what separates it from carb cleaner but it's amazing stuff. It won't instantly clean up glop but given some time it might have worked. I put it in my scoots and the Rebel before winter and they all work cleanly in the spring.

kz1000st said...

Here this will fix it.

http://www.partsforscooters.com/106-96-Bando-Belt?sc=38&category=138773

kz1000st said...

Check this out.

http://www.partsforscooters.com/scooter-parts-diagrams/50cc-QMB139-4-Stroke-Clutch-and-Variator-Parts_2?range=31%2C51%2C51

Note that a stock belt is $14.99, a Bando is $28.00

Paul Smith said...

Not sure what brand the new belt is and I haven't gotten into the cvt to get at the old one, but I do think the belt only blew because it was overstressed from the recent issues with the engine racing. When I got it back from the shop it would only run at high revs.