Gas Issue, Vacuum Issue....not sure  By  scripting25 (Read 3,515 times)

Alright gang. I did some testing today and took notes.

So I started by taking a casual ride around the hood. Ran like a champ.
I decided to start by checking the carb drain hose while the scooter was running fine.
Does fuel come out after successfully riding around?
Yes.

Does it spit fuel out the drain hose while trying to crank over, again after the scooter ran fine?
Yes.

So now I plug the carb drain hose back up.
Now it doesn't want to start. It's exhibiting the same symptoms as before, won't stay running, sounds like gas isn't getting in. Seems I've made it mad.

So... since it's angry and won't stay running, lets test with carb cleaner.

Lets spray carb cleaner on the back of the carb, the exhaust side I guess. What does it do?
Now its really mad and doesn't even want to kick over.
I tried a few times, nothing.

Ok, lets spray carb cleaner on the front of the carb, intake side I guess. What does it do?
It starts up and runs. Hmm... could be coincidence but it is running now.

So with it running I spray carb cleaner alllllll over the intake, what does it do, does the idle rev up?
No, nothing changes. Still idling fine. Zero change.

With it still running, I spray carb cleaner allllll over the exhaust side, what does it do, does the idle rev up?
No, nothing changes. Still idling fine. Zero change.

Lets go for a test ride since it's running ok.

30' down the road.... it dies out.

Ok, so it crapped out. Does fuel come out the carb drain hose?
Yes.

Does fuel come out while still unplugged and trying to start it?
Yes

So.....I put it away for the night.

I still have my wife's carb in my scoot. However, I am still using my auto choke thing. It was easier to take the 2 screws out and disconnect the auto choke and re-use it as opposed to un-wiring it all the way and using her's.
Perhaps the auto choke isn't disengaging?
I'll use her's tomorrow and test that next but wanted to get my testing details out to you guys for more advise.

late to the party again as usual,,,does the vacuum line to the auto fuel tap have fuel in it??? perhaps the diaphragm has a hole in it,,,on the electrical side try running a ground to the engine,,,frame to a valve cover bolt,,,i've seen bad engine grounds create running issues,,,start fine then die out when warm,,(,an edit,,,check your exhaust also,,,a restricted exhaust will create conditions such as this as well,,a pinched pipe or internal collapse in the silencer will cause a no run issue as well when under load,,,but idle fine)

yes the one with the Y,,,pull it from the manifold,,,it should be dry with no liquid fuel in it,,,if there is pull the individual lines off the Y and find out which one has the fuel in it,,,

Alright peeps, today's update is as follows:
Switching out the automatic choke thing didn't make a difference.
No fuel comes out the Y connector hose line, I checked it by unplugging from the manifold.

Volt meter reads a good 12V+ from positive terminal to valve cover head.
With motor off. Reads a touch better with motor running.

It reads nothing from negative terminal to valve cover head with motor off.
It reads -1 with motor turned on from negative terminal to valve cover head.
Is that normal?

Here's a pic of the current spark plug.
I can get a new spark later and test.


The issue I'm having can be triggered by simply riding around a little bit, not having to be WOT.
I actually made it mad the other day by releasing the carb overflow hose.
I plugged the hose back up and the scoot was not wanting to run right.

Is this where I would check the clip?


If so, how do I get the needle out of the harness? I tried to twist and pull but doesn't want to come out and I don't want to break it.

There is usually a Phillips head screw that sits inside where the needle head sits. Unscrew that, then the needle should fall out.

And obviously the spark plug looks like you are running way to rich.