Bike stalls when coming to a stop

[Vision]

Hi All. Recently my bike has been stalling out. It runs fine until the engine is warm, then it stalls out when coming to a stop or starting from a stop. I'll be stranded for 10-15 minutes. The starter will be working, but it won't start seemingly until something cools down. Then it will start, it will run fast, and may stall/strand me again depending on how far from home I am and how many times I have to come to a stop.

After checking a few things and doing a valve job I believe the problem is gas is being cut off from the engine when the engine is warm. Is there anything I should do other than replace the carburetor? 

[Iahawk]

this wouldn't be another one of those 'gas cap not venting, killing motor' things, would it? Seems to be more common on some models (can't recall which..)
The diagnosis is to pull the cap after bike dies and see if it will restart. If yes, then the vent in the cap is blocked.

[Vision]

I don't know. I did open the gas cap during one stall and that didn't change the timeline of the bike not starting/restarting.

I don't think the cap has a vent it in. I believe the vent is a tube off the tank which runs into a charcoal canister/emissions device. I can't find a video to find our more about it.

The fuel filter is clear and appears fine.

[Ruffus]

AFAIK the Agility 125 has a vacuum operated fuel pump, a greyish square or round alu piece with at least three thin hoses on it.

(Some have the electric pump already within fuel tank. To be seen.)

 Should sit on scoots RH lower frame. Maybe check all this hoses and the pump itself for cracks (diaphragm inside).
For testing reasons fuel filter completely out.

Second suspect would be ignition line:
-plug, cap, cable, coil
Check or renew plug, cap and cable

Third but not very likely, totally clogged airfilter.

[Vision]

It's gotten warmer so work can continue on this issue. I think the problem may have been a dying battery and the CDI is DC based so that's what was causing the stalling. Installed a new battery and a quick test drive went well. Hope that was the problem.

[Vision]

Well I was wrong. One test drive went well and the next failed (bike stalled out)- in the exact same spot. I think that makes 3 stall outs at the same stop sign. I'm going to pull the carb off.

[Tromper]

Just food for thought, I had a similar issue with my People s200 when the breather tube that runs from the valve cover cracked.
Rare I assume, but glancing at the service manual looks like you have the same setup mine did.

[Vision]

This morning the bike started up and ran for a few minutes after the carb was cleaned and reinstalled so that's good news.

I'm thinking the issue is the petcock isn't getting enough vacuum for it to release gas. Is there any other element involved with vacuum to the petcock besides vacuum from a running cylinder and the hose lines?

[Ruffus]

Easy to check:
- sideline vacuum pump
- direct fuel supply from a bottle
- scoot runs without attitudes, prob located

Carbs, once clogged, are pretty hard to clean again, if not subbed in an ultrasound bath.

[Vision]

Good news, a lot of progress was made today. I confirmed the fuel system is pumping fuel into the carb when the bike is running. The biggest surprise is the bike became easier to start once the puke tube was emptied. Why would that be?

Then after changing the spark plug it successfully completed a test drive. After getting back I tried restarting it a few times and about half the times it worked and then it became hard to start again- but did by pumping the throttle when turning over. Not sure why that would be. It will be interesting to see how this week goes.

[Ruffus]

Seems to me a carb prob, maybe consider (pls see link) might be the less expensive fix.

https://www.kymcoforum.com/index.php?topic=35081.0

[JJJoseph]

You didn't say if it's carburetor or fuel-injected. It makes a big difference when trying to assist from far away!  A carb will have an electric choke which can cause trouble like this, for instance.

[Vision]

The Agility 125 has a carb; all gy6's do.

It stalled and wouldn't restart on yesterday's test drive. My current theory is the ignition coil is going bad so it's being replaced.

[Iahawk]

The Agility 125 has a carb; all gy6's do.

not completely accurate...your 125cc is a smaller version of the 163cc I had in my People S200 (163 may be bored out, used to have a chart which showed bore and stroke of both). Mine was carbureted. The Like 200i has the same 163cc motor but it is fuel injected.

[Vision]

I stand corrected.