2007 Tank Urban Classic 150cc won't start

[ransome]

 I have a 2007 Tank Urban Classic.63 miles.Was running fine, now it won't start.Turns over well.Tried no throttle, full throttle, couple of twists ect. Thought it might be flooded, let it sit overnight, still it won't catch. Let me know what to try next..thanks
 

[Sparky]

The first thing to look at is the kill switch, they have a tendency to stick closed. Unplug the electrical connector from the back of the switch and see if the engine will start. If so, you know it was the switch.
If it still won't start, then you need to check to be sure you have the three basics; fuel, air, & spark. That's all the engine needs to fire.
Pull your sparkplug out, put it in the plug wire, ground it against the engine and crank the engine to see if you have spark. If not, it could be the pick-up coil (Magneto). I have had to replace one on a 250 Roketa, and I know there was a rash of Tank 150's that had bad ones too.
It could also be any of the other components that make up the firing circuit so, if you get stumped, write back.
 

[ransome]

 Ok, I unplugged the kill switch, no luck.Then I removed the rear body to get to the air cleaner assembly, they don't make it very easy to change the air filter.Shot some starter fluid into the intake and the scooter started right up, it would only run as long as the stater fluid held out.Next I unplugged the fuel line right before the fuel filter(see photo)and ran the starter, I expected fuel to shoot out but nothing came out.Allright what now, the fuel pump or vacuum lines? Let me know...

[Sparky]

If your fuel tank is above the engine, (gravity feed) then the item in question is a vacuum operated valve. These have been a problem also. remove it, and open it up (if it has screws to do so) there is probably a pin hole in the diaphragm. Order a replacement from AllPro Powersports   @ 909-983-6200.

[waltereagle]

Hey Ransome,

Please let us know what happens and what the fix is.    I am going to pick up my Urban Classic 150 from AllPro Powersports next week and plan to ride it home on her maiden voyage...

[Fox]

Sounds like a vacuum leak. Instead of cranking the motor, I would try just disconnecting the vacuum hose from the intake and create a vacuum with your mouth to see if you can get the fuel valve to open.  Save your battery and starter.   

[ransome]

 Tube #1 goes to the gas tank(in the floorboard).Tube#2 is a larger tube that goes to the top of the engine(it only looks like it is attached to the vacuum tree). I made a makeshift gravity feed tank and plugged it in right before the fuel filter so I could test that as well.The scooter started right up and ran great, although it ran at high rpm I am guessing from bypassing the vacuum pump. I spent a lot of time looking at the vacuum connections, they all seem tight with no kinks.

[ransome]

Sounds like a vacuum leak. Instead of cranking the motor, I would try just disconnecting the vacuum hose from the intake and create a vacuum with your mouth to see if you can get the fuel valve to open.  Save your battery and starter.   

 How would I know if the fuel valve is open? By the way I did try suctioning the tube right by the red arrow and got a mouth full of gas...

[Fox]

  I made a makeshift gravity feed tank and plugged it in right before the fuel filter so I could test that as well.The scooter started right up and ran great, although it ran at high rpm I am guessing from bypassing the vacuum pump. I spent a lot of time looking at the vacuum connections, they all seem tight with no kinks.

Well, you isolated the problem. The fuel valve is bad.  It's there as a safety device. The auto choke is probably why it's idling high. It will slow down after a couple minutes. If it does not, then you may need to disconnect and plug the line that is running from the tee fitting to the valve.  You can leave the fuel valve by-passed if you want. It should be ok until you can get a new one.

Maybe there's grit in it. Try dis-assembling it. You might be able to fix it. At the very least, it will show you how it works and you will have learned something new. 

[ransome]

  I made a makeshift gravity feed tank and plugged it in right before the fuel filter so I could test that as well.The scooter started right up and ran great, although it ran at high rpm I am guessing from bypassing the vacuum pump. I spent a lot of time looking at the vacuum connections, they all seem tight with no kinks.

Well, you isolated the problem. The fuel valve is bad.  It's there as a safety device. The auto choke is probably why it's idling high. It will slow down after a couple minutes. If it does not, then you may need to disconnect and plug the line that is running from the tee fitting to the valve.  You can leave the fuel valve by-passed if you want. It should be ok until you can get a new one.

Maybe there's grit in it. Try dis-assembling it. You might be able to fix it. At the very least, it will show you how it works and you will have learned something new. 

 My tank is lower than the carb, don't I need the fuel valve to pump gas to the carb?

[Fox]

Well, now I'm confused. Maybe that thing is a fuel pump that uses engine vacuum for energy.

 If your tank is lower than the carb it would have to be unless there is a small electric pump near the tank under the floor board. SPARKY!  WTF! 

 

[Sparky]

Well first of all, you're lucky to be alive. Swallowing as little as a 1/2 teaspoon of gasoline can kill you. Never use your mouth to do things like this. Buy a hand held vacuum testing pump at your local auto parts store. (they run about $20-$30.)
Second, you sucked on the wrong line. You need to put suction on the other line that comes off the same side of the fuel pump, (notice that it attaches to the other side of the diaphragm in the pump) and see if fuel flows out of line #2.
And yes, you do need a fuel pump to draw fuel from the tank to the carb if the tank is lower than the carb. Check to be sure the fuel line doesn't loop up above the carb bowl, and then down to the pump, this can cause an air "pocket" that will cause the engine to starve for fuel as it runs. The fuel line should run "downhill" to the pump, and then "uphill" to the carb bowl. If the assembler mounted the pump above the fuel level in the tank, it may not have enough suction to draw fuel uphill to the carb.

[Fox]

   I would bet 5 bucks that there's some grit in the fuel pump/valve. 

[ransome]

 Ok, it runs now.Here is what I did..I hooked my makeshift gravity feed to the fuel valve(using the nipple that went to the gas tank) then when it was running well I switched from the gravity feed to the gas tank line, to my surprise it stayed running. Maybe the valve needed to be primed, or there was a bubble or dirt in the valve.But thanks again for all the help and support on this problem.Without forums like this, I never would have bought a Chinese scooter. But with all the big brains here, hopefully we can keep the scooters running.



One more thing though, I found a second nipple coming out of the gas tank( on the opposite side), maybe it was a vent.There was no hose on it and some gas was dribbling out, I put a hose on it and run it under the scooter, let me know what you think..

[Fox]

  I think I'm glad my 50's gas tank is above the carb. and I don't have that "tee" fitting setup. 

 Glad you got it sorted!