|
|
Post by cyborg on Jul 2, 2015 8:13:47 GMT -5
i agree do the valves,,once they "seat" or wear into the seat they are actually receeding into the head exposing more valve stem,,,making them" longer"so the lash gap goes away,,check your gas cap you may have a venting problem,,,run it and when it stalls quickly remove the fill cap if you hear air rush into the tank ,,,,bingo,,,,i would go over all the electrical connections also including all ignition terminations starting at the cdi trigger by the flywheel,and i would also check the intake manifold and carb mounting bolts and nuts
|
|
|
|
Post by steve on Jul 2, 2015 12:52:00 GMT -5
I am glad you tried bypassing the petcock, as those can be an issue. With the carbs, you only really can adjust the idle. There is no adjustment that would make it go from running really rough, and cutting off, to running right, with the A/F adjustments. Unless the carb was defective, it came from the factory ready to run under throttle.
So, you have eliminated the carburetor, and the fuel delivery system. I think that it is one of 2 things.
1: the valves. The valves get really hot, and do go out of adjustment. It is gradual, but the effect can be sudden. The gap can start getting smaller, or larger, and you won't be able to tell a difference until they get past a certain threshold. Then, the effect can be that the engine goes from running relatively fine, to running really rough.
2. You have an air/vacuum leak somewhere. After adjusting the valves, if it is still running roughly, I would like you to replace the intake manifold, and all of the vacuum hoses coming off of that intake manifold, that are attached to 1 or 2 nipples.
|
|
New Rider
Currently Offline
Posts: 2 
Likes: 0
Joined: Feb 1, 2018 9:47:41 GMT -5
|
Post by jonrust1980 on Feb 1, 2018 9:56:58 GMT -5
I have a Tao 125 ATV starts and runs 30 seconds and dies if I jack the back tires up and put it in drive and mash the gas it will run all day long it's just when there is weight on it please help
|
|
New Rider
Currently Offline
Posts: 2
Likes: 0
Joined: Feb 1, 2018 9:47:41 GMT -5
|
Post by jonrust1980 on Feb 1, 2018 9:58:59 GMT -5
I have a Tao 125 ATV starts and runs 30 seconds and dies if I jack the back tires up and put it in drive and mash the gas it will run all day long it's just when there is weight on it please help It also sounds like it sucking a bunch of air in around carb maybe from air filter I've sprayed around it and it doesn't rive up |
|
Freshman Rider
Currently Offline
Posts: 82
Likes: 4
Joined: Mar 18, 2017 11:12:13 GMT -5
|
Post by 125scooterbro on Feb 7, 2018 3:11:43 GMT -5
I have a Tao 125 ATV starts and runs 30 seconds and dies if I jack the back tires up and put it in drive and mash the gas it will run all day long it's just when there is weight on it please help It also sounds like it sucking a bunch of air in around carb maybe from air filter I've sprayed around it and it doesn't rive up have you replace the cdi, check engine pressure? In the worst case you have a top end problem but dont go there yet, start with the small things, i would take all the plastic apart and look very closely at the wiring |
|
|
|
Post by chewbaca on Feb 7, 2018 11:13:44 GMT -5
its actually extremely easy to check the top end health of your motor
remove the CVT cover
put on a leather glove, i have cut myself a number of times no need for you to
grab the variator fan
turn it counter clockwise
it should be fairly easy to turn until you get to the compression stroke
then the air being compressed should give heavy resistance
until it bounces over into the power stroke
if you can't tell where the compression stroke is you'll be doin a valve job at the least.
|
|
New Rider
Currently Offline
Posts: 1
Likes: 0
Joined: Sept 14, 2019 21:00:02 GMT -5
|
Post by amberbob on Sept 14, 2019 21:26:03 GMT -5
It could be the automatic choke. I don't believe they come with a new carburetor. it's a separate electrical component it basically provides a rich fuel mixture for starting and then after about a minute or two minutes it heats and expands and plugs an inlet hole in the carburetor so the(running) mixture is attained. Also make sure you tune your carb after it has fully expanded.
Maybe I'm not an expert(at all).
|
|
New Rider
Currently Offline
Posts: 1
Likes: 0
Joined: Jul 14, 2021 13:59:17 GMT -5
|
Post by snakeoilii on Jul 14, 2021 14:12:09 GMT -5
Hello all,
I'm new to this site. Aczanderna's issue is what attracted me to the site. Did you ever resolve the starting and stalling issue ? I have a 49cc Jincheng gy6 motor doing exactly what your bike is doing. The vac. petcock is working fine, direct fuel feed doesn't help. Mine is a 2007 so Im trying not to replace all the parts you did. It was bad enough taking all the body parts off.
Snakeoilii
|
|
|
|
Post by w650 on Aug 3, 2021 16:02:11 GMT -5
Valve adjustment. A 50cc QMB engine runs its valve clearance at .002 inch. It doesn't take long before the exhaust valve settles in and clearance goes to zero, which causes the valve to be held open and lose compression.
Look on Youtube for videos on how to do the job.
|
|
|
|
Post by geh3333 on Aug 4, 2021 1:30:49 GMT -5
Possibly a pinched gas tank vent hose . I had the exact same issue
|
|
|
|
Post by geh3333 on Aug 4, 2021 1:32:08 GMT -5
Same symptoms . Runs a bit then stalls , then sits a bit then runs again , then stalls .
|
|
New Rider
Currently Offline
Posts: 2
Likes: 0
Joined: Aug 8, 2021 17:28:19 GMT -5
|
Post by cem5320 on Aug 8, 2021 17:29:58 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 |
|
|
|
Post by geh3333 on Aug 10, 2021 17:28:54 GMT -5
He didn't say anything about the gas tank vent hose. Wonder if he checked it. It will cause those exact symptoms.
|
|
