stalls 10 seconds after start ???

[love2ride2222]

What is the reason for this ? I am having big problems to just start normally. I have checked for air leaks , I have the carb adjusted almost all the way rich , I've tried adjusting the rich /lean jet to no avail fixing the problem. I checked the auto choke , not sure if it is bad or not. I pull it all the way off and sometimes it does then idles ( but that  I don't think gives an answer because it is letting both air and fuel when its off ) and I let it warm up and put it back in. I purchased a new one and just stuck it  in the hole( which would allow it be rich as should be upon starting ) incase the old one has the needle broken down causing a lean mix. I installed it but nothing changed.
Something to add , maybe help with this mystery is that when the weather is back being hot or warmer ( I live in Florida ) it starts and idles fine. I have a pod air filter so nothing would be blocking the air I don't think .

[CROSSBOLT]

Any chance this machine sat unused for a long time before this problem? Long time = months/years.

[love2ride2222]

I ride it every day or several times a week . I talked to a scooter mechanic today. I told him a few things that are apparent and going on, such as the plug has been showing hot even with the Arriche carb tuned/turned all the way in rich , exhaust is loud even with new pipe , some reason pipe wont seal , bolts constantly loosen  . He said to change the plug , as he says he changes them every few months. I don't see the need I owned this for 14 years and have gone years with out changing it , but Ill put another in. I changed the fuel filter the other day , nothing changed . He said the reeds could be bad  but I don't think so . I checked them a few months back looked strong , no light came through ,etc etc. Ill check again .  It idles sometimes for 30 secs and then makes this POOOOOOF sound out the exhaust and dies.

[CROSSBOLT]

The plug tells the story that you have an intake leak somewhere between the carb and the reeds.

[CROSSBOLT]

Just thought of another possibility: have you checked the vacuum operated fuel valve?

[love2ride2222]

Howdy.

No I don't  think so what is  vacuum operated fuel valve  ?    But I had a dream while sleeping about something I remembered someone saying about a valve in gas tank lid  . If I remember correctly the lids have some small simple one way valve for air and if it somehow gets blocked it can mess things up  ?

I've checked a variety of ways for air leaks , none seem apparent , except the exhaust . Though I have not pulled the carb intake to look at the reeds any time recently, guess Im gonna go an check.  The mechanic ( different answer then others ) says the exhaust leak doesn't do anything bad , he says they race these with no exhaust . Idk , I always was under the impression the exhaust we put on these have particular tuning and give our bikes extra power.

[CROSSBOLT]

There are two vacuum valves on most bikes, one for fuel tank vent and one for fuel feed to carb. Either one sticking can cause the engine to run poorly or not at all. The fact that it runs for 10 seconds means the run/stop switch on the handlebar is RUN!

Two-strokes may or may not have Reed valves. I do not know if yours has them or not but you have one or more of the three causes: 1. Stuck vent valve, 2. Stuck fuel valve or 3. Air/ vacuum leak. That's why your plug color is white and why it quits quickly.

The "tuned" two-stroke exhaust pipe can produce amazing engine outputs over just a muffler. Running any engine without either a muffler or exhaust pipe of some kind is terrible practice. Especially 2t engines have an exceedingly irritating sound with nothing on the exhaust port.

[eamartin]

Howdy.

 so what is  vacuum operated fuel valve  ?    But I had a dream while sleeping about something I remembered someone saying about a valve in gas tank lid  . If I remember correctly the lids have some small simple one way valve for air and if it somehow gets blocked it can mess things up  ?

Vacuum operated fuel valve uses vacuum (sometimes via a hose from the intake) to open the fuel valve allowing fuel to flow to the carburetor.  You can check this by first,disconnecting the fuel hose at the carburetor and directing this hose into a container; then, disconnect the vacuum hose from the intake.  Now, draw in air on the disconnected vacuum hose like you're sucking a soda straw, hold that vacuum with your tongue, and watch to see if fuel begins to run into the container.  If it runs, the fuel valve is working. 

As for the valve in the gas tank lid, just loosen the gas tank lid and ride.  If the problem persists, the lid is not the problem.

[love2ride2222]

Sorry for late reply, just  did that today. So there are 2 lines to the carb as you said . I pulled them off drew in air like you explained and the fuel flooded out the other.  I got a propane the other day because I am so fed up with this . I was trying to use it to detect leaks , but something happened to the propane tank , it was not full or something and that was then the end of my test.  I held it around the intake connection  and the flange where the reed is and nothing changed. If I held directly at the carb opening the engine would die. I put a new plug it last week to see if that did anything different , I pulled it after riding it and it is very white.

[CROSSBOLT]

Too white spark plug = too lean = air/vacuum leak, jet too small, starve for fuel, etc.
Too black spark plug = too rich = choke/ auto rich too much, clogged air filter, jet too large, etc.
Tan spark plug = everything perfect!
All this is with engine under normal load for  about 15 minutes after warm-up....

[eamartin]

You seem to have determined that the vacuum operated fuel valve is working properly.  I re-read the posts and it does not appear that the jets have been removed for inspection.  Make sure they are clear (i.e. you can see light through them).  By the way, what is an Arriche carb?

[eamartin]

Also,  I have no idea of your exhaust set-up or your jet sizes.  But...a pod type filter will allow a lot more air to enter the carb than the factory filter and can cause a lean issue.   

[love2ride2222]

Yes its lean , it has been for a little while now . I cant figure it out  that is one reason why I am here.
Yes pulled a few weeks ago , jet is clear , and its large , not stock and scooter was showing gray plug for years with same size carb and jet.  Im just so confused , its not that much to these engines .  The exhaust is still leaking at the exhaust port( or its loud coming from somewhere ) , something is wrong down there . Ive been advised to redrill the exhaust port threads but am afraid to do that .  The power is still with this kitted scoot. It launches like a rocket.

I had a Tecnagas  r - next or what its called now I have a reverse made by GIANNELLI. Neither exhaust changed the leak or the plug color. it has a pod filter.

  arreche 19mm  Carb   

Actually this is more accurate  https://www.ebay.com/itm/Arreche-19mm-Kymco-Carburetor-/232559475481
I just changed the link.

[eamartin]

I'm not familiar with this carb.  Aren't there 2 jets?

[scooterfan]

The problem can be caused by a faulty CDI, or insufficient Voltage supplied to the CDI.
Make sure the battery is fully charged, and the battery terminals are clean. Specially if your scooter has a DC CDI, the engine will not run properly if power supply to the CDI is not correct.
If the battery is fully charged, passed a proper load test at a specialist, all terminals are clean, and you still experience a problem - maybe you should try another CDI.  Specially if your scooter has a DC CDI.