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Post by aczanderna on Mar 24, 2014 16:53:18 GMT -5
I have a 2012 TaoTao CY50-T3 scooter. I've had it since last summer and never really had any issues with it other than running poorly in michigan cold (expected). A week or two ago I got it out to drive it to class and it started stalling after I'd get a couple hundred yards down the road. After stalling it wouldn't start again unless I let it sit for a minute. Very frustrating. Then every once in a while it'll start up and run great with no problems. Problem has gotten progressively worse, so my dad and I replaced the following trying to narrow down the problem:
Carburetor
Fuel Filter
Spark Plug (NGK)
Battery
Checked the air filter, it was fine.
Added sea foam to the gas
After all this and the present symptoms, we were sure it had to be the vacuum petcock so I ordered a new one and installed it today. No dice. It'll start right away and run for about 30 seconds and then slowly bog down and die. Doesn't matter if I just let it idle or rev the engine (revs fine). Just seems like it has gas at first and then slowly runs out. I could be wrong.
I'm getting extremely frustrated here as this is my main form of transportation at college. I also don't have any tools at the moment other than the crappy little tool kit that came with it. PLEASE any help is appreciated. Thank you
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Post by frederick on Mar 24, 2014 18:54:30 GMT -5
Make sure there are no vacuum leaks. Likely the valves are to tight. This will require tools to remedy. A feeler gage and a 9 millimeter box end wrench to set the valve lash at .003" or maybe a little more. Each scooter likes its valve lash set differently it seems.
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Post by JerryScript on Mar 24, 2014 19:26:21 GMT -5
When you installed the new carb, how did you tune it? When it dies, does it make any popping or backfire sounds? What happens if you try to rev it about 15 seconds after starting it?
I'm wondering if your enricher has failed? If so, it could be bogging out due to too much fuel once warmed up.
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Post by aczanderna on Mar 24, 2014 19:37:37 GMT -5
We didn't do anything to the new carb just figured it should be good enough to work as it came, which I realize is naive but it acted the same before and after we changed the carb. No popping or anything like that. It runs great while it lasts just shortly after it gradually dies. And correct me if I'm wrong, but isn't the enricher part of the carb? If so that wouldn't be it because we put a brand new carb on. And I don't think it's getting too much fuel once it warms up because it won't run long enough to get warm. I should also add that the old spark plug looked fine when we took it out
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Post by aczanderna on Mar 24, 2014 19:39:52 GMT -5
Make sure there are no vacuum leaks. Likely the valves are to tight. This will require tools to remedy. A feeler gage and a 9 millimeter box end wrench to set the valve lash at .003" or maybe a little more. Each scooter likes its valve lash set differently it seems. Never done this before, how much of an operation is it gonna be to get to the valves if i do get the proper tools? |
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Post by alleyoop on Mar 24, 2014 20:29:00 GMT -5
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Post by frederick on Mar 24, 2014 20:32:27 GMT -5
Yep thats how to do it. Valve adjustment is considered routine maintenance for the qmb chinese scooter engine.
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Post by aczanderna on Mar 24, 2014 20:38:14 GMT -5
Yep thats how to do it. Valve adjustment is considered routine maintenance for the qmb chinese scooter engine. My only question is would the valves go out of adjustment so suddenly? I really don't have any experience with this but it seems like it would happen gradually |
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Post by frederick on Mar 24, 2014 20:51:05 GMT -5
It does happen gradually even though it seemed suddenly.They have been going out of adjustment from mile one actually. It is the result of the valves seating into the cylinder head. As miles add up the valves finish seating in and the need for adjustment tends to decrease in frequency. Regular oil changes with good oil is also helpful in this regard. Note that valve adjustment is likely the culprit but there can be other issues such as CDI timing. I even know of a cracked piston that happened and drove us insane trying to diagnose. Basically check the most likely things first.
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Post by alleyoop on Mar 24, 2014 20:58:21 GMT -5
Some times they come with tight valves right from the factory or set with not much of a gap and that will cause them to loose the gap much sooner.
Alleyoop
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Post by aczanderna on Mar 25, 2014 0:52:23 GMT -5
Update: I bypassed the petcock by connecting the carb right to the fuel filter and it made no difference, so it's definitely not a problem with getting gas to the carb.
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Post by ramblinman on Mar 25, 2014 1:26:43 GMT -5
Update: I bypassed the petcock by connecting the carb right to the fuel filter and it made no difference, so it's definitely not a problem with getting gas to the carb. agree with everyone else, start with valve adjustment. i do mine about every 1,000-2,000km on my old atm50 and just did one on my new 150 Jonway with only 145km on the odometer. the first time it probably took me an hour (maybe a little longer) but now can do it in under 30 minutes on my atm50. just watch many how to vids until you feel comfortable doing it yourself. you will definitely notice a change in performance afterwards and will likely fix your problem. note: you will have to tune the carb after valve adjustment. here is another how to vid. i prefer to use a small pair of vise grips and a 9mm wrench but his method with his tools works also just a bit more difficult imo. |
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Post by JerryScript on Mar 25, 2014 2:46:47 GMT -5
Softer metal alloys is one generally accepted reason the valves need adjustment more often on chinese scooters. You have a controlled explosion pressing the valves against the head. The lower quality metal and/or forging means the metal compresses a bit. It actually happens in all engines over time. With a gap of only .003, the tiniest compression of the metal can make a difference!
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Post by scootergang on Jul 1, 2015 20:47:37 GMT -5
I have a 2012 TaoTao CY50-T3 scooter. I've had it since last summer and never really had any issues with it other than running poorly in michigan cold (expected). A week or two ago I got it out to drive it to class and it started stalling after I'd get a couple hundred yards down the road. After stalling it wouldn't start again unless I let it sit for a minute. Very frustrating. Then every once in a while it'll start up and run great with no problems. Problem has gotten progressively worse, so my dad and I replaced the following trying to narrow down the problem: Carburetor Fuel Filter Spark Plug (NGK) Battery Checked the air filter, it was fine. Added sea foam to the gas After all this and the present symptoms, we were sure it had to be the vacuum petcock so I ordered a new one and installed it today. No dice. It'll start right away and run for about 30 seconds and then slowly bog down and die. Doesn't matter if I just let it idle or rev the engine (revs fine). Just seems like it has gas at first and then slowly runs out. I could be wrong. I'm getting extremely frustrated here as this is my main form of transportation at college. I also don't have any tools at the moment other than the crappy little tool kit that came with it. PLEASE any help is appreciated. Thank you |
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Post by scootergang on Jul 1, 2015 20:50:06 GMT -5
Hey bud. Ran into the very same issue. I adjusted my valves....same outcome even.
Buuuuut....found the issue!!!
Turned out to be a bad intake o ring gasket on the bottom side of intake where it bolts to the cylinder.
Runs better than ever.
Hope it helps!!!
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..BAD TO THE BONE..