New Taotao ATM50-A1 Bogs Down Under Throttle By jdlev (Read 30,570 times)

[jdlev]

2011 TaoTao ATM50-A1

I can't figure this out. First of all, this Chinese carb is bull crap. You can't crack the housing to get to the floats. I had to drill out some brass cap to get to the mixture screw.

I can't get the carb dialed in to save my life, and am not sure what the heck is going wrong. It has an autochoke...which I hate, and might be the source of the problem.

Symptoms:
Difficult to start
Erratic Idle - Engine spins up with no throttle
Bogs down under throttle (typically greater than 25%)...but you can rev it...you just can't leave it WO.

I can't figure it out. I pulled the carb and cleaned (what I could) of it. Put it back in, and the same symptoms....hard to start and bogs down at full throttle. Pulled the air filter to get straight air in. Same problem. Sprayed the entire engine with soap to see if I could find any vaccum leaks, and nothing. Pulled the carb again, and drilled out the retarded cap, and went through the full spectrum from lean to rich (to the point that the drain tube on the bottom was dripping gas)...and THE SAME FREAKIN PROBLEM...bogs down under throttle I will say that it has become a bit easier to start since richening the mixture.

What the heck should I do? If I should replace the carb...can anyone recommend a good one for under $50? Should I replace the vacuum tubes? This has annoyed me to no end!

Thanks for any help!

[rob63]

Have you checked and set your valves, they`re sometimes the cause of poor starting ? Here`s a tutorial to help scooterdoc.proboards.com/index.cgi?board=engine&action=display&thread=140
For a carb do a search on ebay for gy6 50cc carb and see what comes up, they`re normally available for around $30-$40

[kz1000st]

Yes, check the valves but stop and listen to it. If you hear a hissing noise from somewhere there's a vacuum leak. Use WD-40 to spray down the engine. I had a tube valve go bad when mine was new. The hose was at the front and didn't connect to anything.

[jdlev]

Thanks guys. I hadn't thought of checking the valves. Since it sounds like a big job, I'll try the wd40 method first. Then tear it down if need be.

I guess I'm lucky I enjoy tinkering with these things otherwise I'd be pissed!

[jtoro]

Hey just landed on this thread. What was the verdict. I have exact same sit. Purchased 7/12. Ran great till Oct. Just pulled it out of storage last week and exact same issues you have to the T! Please post what you figured out if anything.

[Alleyoop]

The carbs on the new scoots that come plugged up are set really LEAN to pass emsissions.
You have to richen the fuel ratio mixture up due to the COLDER TEMPS otherwise they will bog and be hard to start.
In cold temps the motor needs a lot more fuel than in hot weather 70+

If you start it will probably idle high due to the ENRICHER feeding it extra fuel for cold starts.
Then the idle will start to come down after 3-5 minutes.

But if after 3-4 minutes the idle goes high and or bounces up and down your are VERY LEAN Richen it up using the FUEL RATIO MIXTURE SCREW. Or if you have a SLIDER TYPE carb the AIR RATIO SCREW on the Air FIlter side.

If you do not know how to adjust it properly let me know.
Alleyoop

[jessetoronto]

Alleyoop, yea please point me to a tutorial on the Fuel mix adjustment please. I have a 50cc ATM TAO TAO.

[Alleyoop]

Hi Jesse,
I am assuming it is a 4 stroke:
Alleyoop

Here is how to adjust your carb and idle:

If your carb has a SCREW near the INTAKE MANIFOLD side the Carb has a FUEL RATIO MIXTURE Adjustment screw.

Turning the Fuel Ratio Mixture Clockwise LEANS it Turning it Counter Clockwise RICHENS it.

The Idle Speed screw is on the Throttle Control Wheel that the Throttle Cable pulls on. The Idle Speed Screw usually has a SPRING under it to keep the setting. Turning that Clockwise RAISES the Idle and Turning it Counter Clockwise LOWERS the Idle.


[red]IF YOUR CARB HAS A SCREW ON THE AIR FILTER SIDE GO SEE 2TS CARB TUNING.[/red]


[red]Follow this procedure to tune the carb: Take your time 1/4 turn to much in either direction makes a big difference.[/red]


[blue]ADJUSTING YOUR FUEL RATIO MIXTURE:[/blue]


[red]YOU WANT THE HIGHEST RPMS OUT OF THE AIR RATIO MIXTURE SCREW:[/red]


Start your scoot and Get The Engine Nice and Hot about 5 minutes so that the Enricher IF it has one is no longer Allowing Extra Fuel to come in. Then do the following to fine tune the Fuel Ratio Mixture:


[blue]FUEL RATIO SCREW:[/blue]


FIRST TRY RICHENNG THE FUEL MIXTURE FROM ITS CURRENT SETTING:

1. [red]RICHEN THE FUEL RATIO MIXTURE:[/red]

Turn the Fuel Mixture Screw COUNTER CLOCKWISE 1/4 of a turn and wait 10 seconds to let the engine catch up with the new setting.

a. If the RPMS go up REPEAT #1 UNTIL the RPMS GO DOWN OR NO CHANGE(then go to b).

b. TURN the Fuel Ratio Mixture Screw CLOCKWISE 1/8 and that should be your highest Fuel Ratio Mixture setting—GO TO #3.

[green]******[/green]If on the FIRST 1/4 TURN from the STARTING Position IN #1 ABOVE the RPMS GO DOWN OR NO CHANGE , turn the Fuel Ratio Mixture Screw Back the 1/4 turn to the Starting position and wait 10 seconds until the engine catches up -- GO TO #2[green] ******[/green]


2.[red]LEAN THE FUEL RATIO MIXTURE:[/red]

Turn the Fuel Mixture Screw CLOCKWISE 1/4 of a turn and wait 10 seconds to let the engine catch up with the new setting.

a. If the RPMS go up REPEAT #2 UNTIL the RPMS GO DOWN OR NO CHANGE(then go to b).

b. TURN the Fuel Mixture Screw COUNTER CLOCKWISE 1/8 and that should be your highest Fuel Ratio Mixture setting—GO TO #3.

[red]IF YOU GOT TO THIS POINT AND NOT INSTRUCTED TO GO TO #3 THAT MEANS THERE WAS NO CHANGE IN RPMS FROM DOING #1 or #2 ABOVE, IT IS TIME TO CLEAN THE CARB:

YOU NEED TO CLEAN YOUR PILOT JET AND PASSAGE AND AIR PASSAGES AND THEN START FROM #1 AGAIN.[/red]


3. [blue]IDLE SPEED SCREW:[/blue]

The Idle Speed Screw on a Carb that are on most 4Ts you will find on the right side on the THROTTLE CONTROL WHEEL. It is the screw with a SPRING on it.

To Lower the IDLE you turn it COUNTER CLOCKWISE to Raise the IDLE you turn it CLOCKWISE.

If after adjusting your Fuel Ratio Mixture your idle is to fast Turn the IDLE SPEED SCREW COUNTER CLOCKWISE. For the 50s-150s they like to idle around 1500-1800rpms, for the 250s+ they like to idle from 1800-2000 rpms, pick the smoothest idle with the rear wheel not spinning ---GO TO #4.

4. [blue]TEST YOUR ADJUSTMENTS:[/blue]

Now give the Throttle a QUICK twist and the RPMS should climb up quickly without hesitation or bogging and come down to where you set your Idle at---GO TO #5.


5. NOW take a ride and try it out, the Fuel Ratio mixture may need a tweak in either direction now that the motor has a load on it.

The tweak will be minor maybe a ¼ turn richer or leaner IF it acts up with a load---GO TO #6


6. When it acts up BACK OFF the throttle about ¼ of an INCH AND HOLD IT THERE:

a. If the motor speeds up it is LEAN you need to richen it up a little.

b. If the motor settles down and or stumbles and then settles down it is RICH you need to LEAN it out a little. GO TO #5 AGAIN.


[blue]Problems with the IDLE:[/blue]

1. Give the throttle a quick twist:

A. If the rpms drop below idle speed, then recovers (or stalls), it is RICH —Turn the Fuel Mixture Screw Clockwise ¼ turns at a time and go to #1.

B. If the rpms do not drop quickly to the idle speed but hang and drop slowly it is LEAN —Turn the Fuel Mixture Screw Counter Clockwise ¼ turns at a time and go to #1.

Left Side Of Carb:




Right Side Of Carb:

[jessetoronto]

Thanks so much. Tackling this tomorrow.