scooter sputtered this morning and then died.

[aschrauth]

Hello everyone.

I have a kymco 125cc that I use daily. So I had a problem this morning. On my way to work Hop on my trusty scooter and make it halfway up my subdivision when suddenly my scooter starts sputtering, I try to give it more throttle but it keeps sputtering, I let off the throttle and it dies completely. So being late for work I walk it back to my garage..... Fast forward to tonight. When I got home I did a thorough inspection,

Cleaned carb jets and entire Carb
Adjusted timing.004 for intake .005 for exhaust.
Checked for spark; Had spark.
Adjusted the mixture screw and idle screw

So far I have done all of these methods and when I try to turn over the engine it cranks but will not start.

I preformed a test where I took the sparkplug out of the socket and stuck my finger in the hole  with the clean carb I did not feel any gasoliene on my finger. As of right now I have the battery on the charger and will try to diagnose the issue tomorrow ( ran out of daylight).

I am probably going to end up ordering a new Carb.

[CROSSBOLT]

I would guess either your vacuum operated fuel valve is stuck shut or your vacuum operated vent valve is stuck shut or both.

[scooterfan]

Did you try a new fuel filter ?
Maybe you can also disconnect the vacuum pipe from the petcock, as well as the fuel pipe at the carb. Then just suck slightly at the loose vacuum pipe by mouth or seringe to see if fuel is running out from the loose fuel pipe. Fuel should be running freely from the fuel pipe when you start sucking.
Just put a container under the fuel pipe before you start sucking.

[Iahawk]

great advice from both Crossbolt and Scooterfan! Much better to try their suggestions before spending money on a carb. It's highly unlikely that your carb just 'stopped working'...it sure sounds like a fuel delivery issue.

[aschrauth]

Ok everyone so I found the issue for the moment. My scooter does not use a vacuum system like others do. Instead it uses gravity to help the gas flow. All I did was remove the fuel line and blow air into the tank. Reinstalled everything and she fired right up. Now I have another issue.

When starting my scooter Idles fine. However once I give it gas it starts to sputter to the point to where it floods the engine if I go complete full throttle, When I deep cleaned the carb I removed every component including the idle mixture screw. For some reason I cannot get the idle mixture screw and the low speed mixture screw sync no matter how much I adjust. Ran out of time today due to limited Daylight but will try again tomorrow. Any help is gladly appreciated. YOU GUYS ROCK!!!

[CROSSBOLT]

Ok everyone so I found the issue for the moment. My scooter does not use a vacuum system like others do. Instead it uses gravity to help the gas flow. All I did was remove the fuel line and blow air into the tank. Reinstalled everything and she fired right up. Now I have another issue.

When starting my scooter Idles fine. However once I give it gas it starts to sputter to the point to where it floods the engine if I go complete full throttle, When I deep cleaned the carb I removed every component including the idle mixture screw. For some reason I cannot get the idle mixture screw and the low speed mixture screw sync no matter how much I adjust. Ran out of time today due to limited Daylight but will try again tomorrow. Any help is gladly appreciated. YOU GUYS ROCK!!!

Well, yes it does use gravity but the vacuum valve opens the fuel line to flow to the carburetor. It is like the old petcock on a real motorcycle except automatic.

Try starting with idle mixture screw 2.5 turns open from seated.

[scooterfan]

Ok everyone so I found the issue for the moment. My scooter does not use a vacuum system like others do. Instead it uses gravity to help the gas flow. All I did was remove the fuel line and blow air into the tank. Reinstalled everything and she fired right up. Now I have another issue.

When starting my scooter Idles fine. However once I give it gas it starts to sputter to the point to where it floods the engine if I go complete full throttle, When I deep cleaned the carb I removed every component including the idle mixture screw. For some reason I cannot get the idle mixture screw and the low speed mixture screw sync no matter how much I adjust. Ran out of time today due to limited Daylight but will try again tomorrow. Any help is gladly appreciated. YOU GUYS ROCK!!!

Quite interesting. Just a couple of questions:
1. What model is this ? Agilty 125 ?
2. Did it originally came with a petcock valve, or has the petcock valve been removed as part of a modification ?
3. When you blew air into the tank - did you remove the old fuel filter before you started blowing air into the tank ?
4. Did you replace the old fuel filter with a new fuel filter - or are you still using the old filter ?

If the scooter originally came with a petcock valve I think the modification is part of your problem. If it came with a petcock valve but it has been removed, and the fuel filter was partly blocked, think there is a possibilty that a partly blocked fuel filter could have kept you going for a while. In such a case I think since you blew air into the tank there is a possibility that the engine might be flooded with fuel now.
Or if the old fuel filter has not been replaced - the old filter might be blocked by dirt again - the same dirt that’s been blown into the tank when you used air.

Bottom line - it is important to know whether the old fuel filter has been replaced or not, and whether this scooter originally came with a petcock valve or not.

[aschrauth]

Quite interesting. Just a couple of questions:
1. What model is this ? Agilty 125 ?

it is a kymco agility 125cc
2. Did it originally came with a petcock valve, or has the petcock valve been removed as part of a modification ?
still has origional oem petcock valve


3. When you blew air into the tank - did you remove the old fuel filter before you started blowing air into the tank ?
removed fuel filter and then blew air into the tank

4. Did you replace the old fuel filter with a new fuel filter - or are you still using the old filter ?

Replaced with new filter


So update on today,  went and reinstalled the old Carb, I had no luck getting the carb to cooperate, I tried adjusting both the idle mixture screw and the idle speed screw to no avail, For some reason I cannot get the engine to increase or decrease rpm with turning of the mixture screw.

My new Carb comes from amazon tomorow, Going to throw it on and see if it changes anything, Here is a video today of the issue.

https://drive.google.com/file/d/1kJgpg5Zc0IBZ1T9kQdIuqTM2-j_XNmxP/view?usp=sharing

[CROSSBOLT]

Is this fuel petcock manually operated?

[aschrauth]

no

[scooterfan]

Ok everyone so I found the issue for the moment. My scooter does not use a vacuum system like others do. Instead it uses gravity to help the gas flow. All I did was remove the fuel line and blow air into the tank. Reinstalled everything and she fired right up. Now I have another issue.

When starting my scooter Idles fine. However once I give it gas it starts to sputter to the point to where it floods the engine if I go complete full throttle, When I deep cleaned the carb I removed every component including the idle mixture screw. For some reason I cannot get the idle mixture screw and the low speed mixture screw sync no matter how much I adjust. Ran out of time today due to limited Daylight but will try again tomorrow. Any help is gladly appreciated. YOU GUYS ROCK!!!

Well since your comments (above) you mentioned the scooter has a petcock valve.

That means your idea that your scooter does not work like other scooters is completely wrong. It actually works exactly like other scooters.

If you did not test the petcock valve like I suggested, the petcock valve can still  cause your problem.
For a start, you need to get rid of the idea that your scooter does not work like other scooters, then test the petcock.

Your answer to Crossbolt’s question was “no” - which to my mind means you do not realize  there will be no gravity feed your scooter unless the petcock valve works properly. The petcock valve actually controls gravity feed on your scooter.
If the engine does not swing or run to cause suction (a vaccuum) at the petcock valve, there would be no way in life that you will have any gravity feed on your scooter.

[aschrauth]

Ok, starting to learn more. My old wolf wx50 ha d a petcock that operated with just one hose. Ill check the petcock tomorow evening, I did install a new fel filtwr.like you stated and.it ran jst fine at idle. However, it cuts ot when i gve it throttle, I have not change d any of the.jets, the inly thing i have messed with is the idle and fule mixtre screw, today I spent three hours trying to adjUst and no luck.

[CROSSBOLT]

Three hours?! Idle stop and idle mixture do not affect high speed. Saw the video. Nice and clean! High speed jet plugged/diaphragm stuck/not moving.

[Iahawk]

from the video it looked like it was idling fine but when you gave it gas it died. On my scoot that was a clogged pilot (slow speed) jet.  Tiny, tiny hole in that jet, can be hard to clean properly.

Have you pulled the carb and re cleaned everything?...or are you just going to put the new carb on and be done with it?

Let us know how this works out.

[aschrauth]

New carb comes in today. Will install after work and let you guys know