Need carburetor help 150cc going to blow my brains out By trunksferret (Read 375 times)

[trunksferret]

I've got a 150cc gy6 motor on a go-kart that is driving me nuts. So the story is my kid was trying to hotwire cuz he lost the key fried the electronics so I replaced the entire harness and all the electronics. While I was doing this I decided to switch the intake to a nibbi and the vacuum pack cock was deleted long ago. Go-kart ran fine before the hot wiring incident. Connected everything back up and connected what I'm assuming is the vacuum line to the intake and when I try to start it fuel is being sucked from the vacuum line port at the top of the carburetor into the intake and it immediately floods the engine. If I remove the vacuum line and connect it from the valve cover to the intake the motor runs but when I give it gas it bogs out and dies. What am I missing. The other thing is when I look up GY6 carburetors most other ones have a vacuum port on the opposite side opposite the enricher and the carburetor I have does not have one there. What I'm assuming is the vacuum Port is actually on the enricher side at the top of the carburetor. I need help would be greatly appreciated

[trunksferret]

Also I can post pictures if there's a place to do so as I am new to the forum

[classacted]

you don't give alot of info about the vehicle.

check the condition of the spark plug and the gap.  check for spark.

loosen the exhaust bolts and put a screw driver between the exhaust and cylinder.  you could still have an obstructed port - check the port (carbon).

after each task see if it starts and runs correctly.

remove the air cleaner.

make sure the spark plug cap is not coming off the plug.  gy6 is notorious for this.

make sure your valves are within acceptable range.  I had problems with this just last week.  spent a whole day making adjustments and retrying just to be 'good at it'.  when the engine started without giving throttle I was happy with it.

still no luck

try this to check if it's getting fuel.  DANGEROUS.  spray gas, wd40, starting fluid, etc in the carb intake and crank to see if you're not getting fuel.  it won't run for long.

I also remove the vacuum valve on my bike.  I let the fuel go directly from tank, thru filter, to carb.  totally removed the valve. 

if your gas cap is defective (not venting), vacuum will develop in the tank and fuel will quit flowing.  as soon as it dies, pull the cap to hear if it sucks air.

whenever I have a carb issue, I just remove it, disassemble it, and put it in an ultrasound.  this has always worked for me, and I am talking hundreds of times.  I don't change any parts from stock.

don't forget good ol water in the carb and the tank.  the gas station LOVES putting as much of that in your gas that they can get away with.

[trunksferret]

Okay so I got an update for you. This carburetor has no vacuum port on the passenger side it only has the overflow on the driver side at the top of the carb. So right now I just have one vacuum line going from the intake manifold to the valve cover. It will start and run but the RPMs are high and as soon as I touch the throttle it bogs out and dies. I'm using a paper air filter and toomy exhaust. Valves are adjusted to 004 and 005. Plug reads rich. The fuel air screw changes things slightly with the RPMs are always very high even with the throttle RPM adjustment all the way out. By this I mean there's no tension on the cable at all and the butterflies completely closed theoretically. I know that most GY6 carburetors have a vacuum port on the passenger side but this one does not and I feel like that's part of the problem but it ran fine before I took it apart.