GY6 having fuel piss out/vacuum issues By zeonsredcomet (Read 19,208 times)

[zeonsredcomet]

Hello, Im new to the forum, but NOT new to scooters. I have fixed TONS of GY6 scooters, but I need a fresh perspective on the current issues with this 150 long case GY6. It is a HUNTER style GY6 and I have replaced the Petcock, engine mounts, brake pads ( I have a question about one of the bolts that go through the assembly and pads themselves on where to find one!)

My main question is this: I replaced the engine mounts, and when I put the engine back on, and double checked all wiring, I now have the carb pissing out gas from the overflow, there isn't even a screw for the overflow and it now passes gas, it wasn't doing this before. The other thing is it DOESN'T start if i have the vacuum line hooked up to the PCV valve that goes into the vacuum diaphragm. If i take the line off and put my thumb over it, i feel vacuum, but when i do that it EVENTUALLY STARTS AND RUNS STRONG.
Am I getting a vacuum leak somewhere?
I have some ideas like taking that line off again, and spraying the intake to check for leaks, and MAYBE replacing the vacuum diaphragm in the carb.

Has anyone had this problem before? If so please give me some ideas, and what you did to get this to stop.

P.S The float bowl height is nice and level.

[sprocket]

You have something hooked up wrong possibly.. and there is no PVC valve on a GY6 do you mean the ACV valve on the right of the carb also called the de-acceleration valve??...you have a vacuum leak or a line not connect right..Pull the cover off the ACV valve and check it out...

[zeonsredcomet]

Im sorry, I thought it was a PCV. It's good to know that's an ACV, what is the primary difference though.

So you think I have a leak somewhere? The bike was running before the mount swap. I double checked all the connections, maybe a line has a kink in it.

I did notice the guys air box has a GIGANTIC tear in it, but it ran before, and now it doesn't.

[zeonsredcomet]

Any Idea why gas is majorly pissing out of the overflow now? It wasn't doing this before.

[sprocket]

PCV is positive crankcase ventilation ..vents the crank case on cars etc... (crap)
ACV is a acceleration cut-off valve...it stops backfiring when you let off the gas...it enriches the engine

Sounds like you have a vacuum hose leaking or you haven't got them hooked up correctly...

The diagram is a basic set-up for most scooter...vacuum and fuel lines

Attachments:

[sprocket]

What overflow?

[zeonsredcomet]

The overflow on the carb bowl is pissing out gas like CRAZY

[Alleyoop]

Which line are you calling an OVERFLOW the hose that is bent near the TOP of the CARB or the hose all the way down at the BOTTOM of the Carb.

If its the ONE AT THE BOTTOM of that Carb, that is your CARB DRAIN hose.
a. If that hose has a sprial wireing on it on the END of it should be a SCREW that shuts off the gas from draining. If it doesn't you lost the shutoff screw, you can get a GOLD tee and stick it in the hole and tape it on or you can bend the hose and zip tie it bent so fuel does not come out or get another screw for it. Best thing to do is take the hose off and take it to a hardward store and get a screw that will fit.

b. If the hose does NOT have spiral wireing on the SHUT OFF SCREW is on the carb itself right next to where the hose is connected to it . Just tighten the screw to stop the fuel from draining out.

IF the hose your talking about is near the TOP of the CARB and is bent down and that is where the gas is coming out of that means your CARB IS NOT SHUTTING off the fuel when the bowl is full. You will have to take the CARB off and Check the FLOAT and plunger to fix it so that it shuts off the fuel from coming in when the bowl is full.
Alleyoop

[zeonsredcomet]

The fuel is coming from the bottom of the bowl like I said
There is no screw, it doesn't seem to have a threading it just is gold, and has a equally long hose over it with a clamp. I guess I could re-check to MAKE SURE it doesn't have a threading which means the screw simply came out.

What should I do about my vacuum problem though. Fresh persepctive is needed.

[sprocket]

Sounds like someone has messed with the drain hose... just get a golf tee and plug the long carb bowl drain hose...

As for the vacuum , we will need pictures.. you have something hooked up wrong or the ACV valve is open and you are loosing vacuum pressure...

Follow the diagram.. and check your connections.. if they are like the diagram it will run...

Probably a good idea to just order a new carb if you are having these problems...

[loose]

Hi, I'm having what I think are vacuum issues also. All lines are clear and petcock diaphragm is intacked (it clicks if you suck and blow). However there doesn't seem that fuel is flowing firstly to the filter or the carby. Any ideas?

[Alleyoop]

LOOSE,
Take the fuel hose off the carb and put it in a cup or whatever.
Then Take the Vacuum hose going to your PETCOCK and SUCK ON IT:
a. gas should flow into the container.
b. If no fuel then IF there is a FUEL FILTER between the End of the Fuel Hose and FUEL FILTER take the fuel filter off.
a. Suck on the Vacuum hose going to the petcock/
1. If fuel flows YOUR FILTER IS CLOGGED get a new one.
2. If fuel does not flow Take the PETCOCK off and see if FUEL FLOWS from the TANK OUT TO THE PETCOCK. BE READY TO BEND THE HOSE SO YOU CAN STOP THE FUEL FROM COMING OUT.
Alleyoop