Getting Gas, but won't start 50cc TaoTao By nehmo (Read 961 times)

[nehmo]

TaoTao ATM-50-A1 with 50cc engine

I can start it using starter fluid, but then it dies after a few seconds.
If I detach the gas hose at the carburetor, and if I use my lungs to such on the tube going to the gas valve, gas will come out of the tube that is supposed to be attached to the carburetor. IOW, the gas valve seems to be working, and the carburetor is getting gas properly.

The engine will start when I squirt starter fluid into the intake manifold tube, but then it dies shortly (apparently, after it finishes the bit of starter fluid).

What's the next troubleshooting step? 

[jct842]

Look for a vacuum leak. Try cranking with the hose off that brings in the gas. It should be coming out pretty good. The ether trick proves the engine is fine and it just needs to have some gas in the carb.

[kz1000st]

Crud in the carburetor and the jets have to be cleaned.

[nehmo]

When I suck on the hose going to the fuel valve, as I said, the valve seems to open because gas flows through the tube that delivers fuel to the carburetor. And by sucking on that line, I can tell that the line, itself, is without any leaks. It's like sucking a closed line, which is what it is. 
I'll change the vacuum line anyway because you seem to suspect it. 
And I'll try only using the vacuum only produced by cranking to activate the fuel valve. 
But I'm beginning to suspect the carburetor is the problem. 
Fuel is getting to the carburetor but not in the fuel-air mixture going to the intake manifold. 

[ucwt]

Maybe you are creating a greater vacuum than the carb..

Check that too.