Idles fine, but dies when I try to ride away/won't restart

[DanielPerrin]

I hope this sounds familiar to someone. My 2009 Buddy 125 died, and wouldn't restart. It will start and idle smoothly, but as soon as I put some real load on it (trying to ride away) then it will die and not restart.

This started when I was riding along at speed and the scooter died. I was able to get it running a few more times for a total of about 4 miles, but it kept dying and eventually wouldn't start any more. I searched ModernBuddy and checked things like spark plug, battery charging, valve gap, etc. After changing the fuel filter and spark plug, it started and idled for more than 10 minutes, then died as soon as I tried to ride away, and would crank but not start.

Today it did the same thing: I got it started, it idled for more than 10 minutes. I could accelerate on the center stand and get the rear tire turning. As soon as I took it off the center stand and tried to ride away, it died/won't restart. It dies right away, without any sputtering.


Here is more information. I have organized this into three sections below, to organize all of these words: 1) what happened when it first died; 2) what I did to try to fix it; 3) what happened after my fixing.

This is what happened a few days ago:
- I had ridden more than 10 miles
- I was driving about 55 MPH
- The motor stopped and I pulled off the road
- If I kept trying then the scooter would start and I could drive somewhere between 1 mile and 50 ft before it died again; I was able to go another 4 miles like this
- During 2 of the 8 times the engine died it sounded like it was backfiring, but this backfiring did not happen every time the engine stopped
- Eventually I could not get it started again, but the starter kept turning over
- AAA towed me home


This is what I did to try to fix it:
- My gas cap is vented; I blew through the cap to verify the holes weren't plugged
- Replaced fuel filter
- Replaced spark plug
- Checked valve gap; intake and exhaust were both within spec, at 0.08 mm
- Cleaned carb main jet, slow jet and float valve with carb cleaner spray
- I didn't want to screw anything up, so I did not clean anything else in the carb, such as any internal passages, the needle jet base or the needle jet
- I have been riding regularly, and add Seafoam every two or three tankfuls


This is what happened after I did the fixing listed above:
- It started and idled for at least 10 minutes. When I tried to ride away then it died and would not restart.
- I had been able to accelerate on the center stand, and the engine speed increased/rear tire turned as expected
- While it was idling the battery read 13.25 volts
- The fuel level in the new filter looked the same before I started it as it did afterwards (when I could not get it started)
- The gas tank is about 1/2 full
- The starter turns over as usual, and periodically even sounds like it is about to start

Any helpful suggestions would be much appreciated. Thanks.

[scootERIK]

My first thought is a bad stator.

Have you tried to start it and ride it without letting it warm up?

Also, how many miles does it have?

[DanielPerrin]

It has 8,500 miles.

I thought the charging voltage at idle would indicate the stator is working. Or am I thinking of something else?

[DanielPerrin]

Have you tried to start it and ride it without letting it warm up?

I will try tomorrow to start it and ride without letting it warm up. I just tried to start it, and it won't start now. It hasn't run in about 3 hours, but it cranks without starting.

[scootERIK]

You should also check if it is getting a good spark. When one of my stators went it still had a spark but it was weak and inconsistent.


Instructional video if you need one.
http://www.youtube.com/watch?v=mUOmsGiirTU

[OldGuy]

Sounds like you are doing all the right checks, but my guess is fuel flow. I wonder if you got some bad gas with water in it. Or maybe got a piece of junk trapped in the wrong part of the carb.

If spark is good, and the air filter is not totally clogged, then fuel is the most likely problem.

[dkw12002]

Sounds like there is still dirt or varnish in the carb main jet to me. Try squirting a little starting fluid into the intake port and see if that allows you to open the throttle and increase the revs. If so, it is probably a dirty carb jet. If so, I would use a half can or so of carb cleaner spraying it as per directions on the can into the intake as the bike is running and again increasing the throttle. Once you do get into the higher revs, then you can also take it out and ride it hard to get some gas flowing through which should solve the problem after a tank or two of gas.

[DanielPerrin]

Have you tried to start it and ride it without letting it warm up?

I tried this morning to ride away as soon as I started it (without warming it up), it died immediately.

Thanks everyone for the suggestions, I will go for the carb cleaner and check the jets, and hopefully that will do the trick.

I'll let everyone know how it goes.

[DanielPerrin]

It was the fuel petcock. Sometimes it would work, but other times it wouldn't even fill the fuel filter. Works like a charm with a new petcock.

Spark was good. Thanks for the link to video of how to check spark.

Thanks for all of your help.

[RoadRambler]

Thank you for reporting back with the solution. I learn so much by reading these threads!