Scooter GY6 Hard Starting (Video)

[micscience]

So I have been having a hard time starting my scooter lately. It has a 80cc BBK installed. It takes about 5-10 seconds in a cold start using the start button. Kick starting from cold takes much longer. Before it would not start at all from kickstart until I fixed two things not sure exactly which one did it the trick but it was a frayed ground chassis wire from the CDI and I replaced the fuel enricher though the one I replaced may still be suspect.

The scooter is running rich I get back fires occasionally when decelerating. Anyways to make a long story short I bought a new carb since my old carb has a little carbon build up inside the main orifice probably from running rich. I have an after market exhaust, performance carb, cam and UNI filter.

Today I noticed either oil or fuel leakage or maybe both. I'm not sure yet where it is coming from but for sure it looks like there is excess fuel when either riding or from cranking. I removed the intake before packing it up and I noticed either fuel or a mixture of fuel and oil getting passed the valves. Here is the video.    youtu.be/Jvw4ezhlVSg

I wanted to document this fixing process so it can maybe help someone with a similar issue and also a little feed back would be nice thank you.

[GrumpyUnk]

Being who I am, that video was useless to me. There was no focus, no direct light on the intake port and valve, and it wobbled so much that focusing on anything was questionable.
If you want to make a documentary that will help, check those produced by 90GTVert who runs this place. His are exemplary.
That said, you should not have liquid fuel in the port where the intake valve is located. If you do have liquid fuel, it is because the carburetor is not stopping fuel flow from the tank, nor is the vacuum petcock stopping the fuel flow(if you have one, otherwise it is you not shutting off the fuel flow manually.)
The float valve will not stop flow if the tank gets pressurized due to sun heat, etc. The float valve my be sticky, have debris preventing sealing or other malady. Fix that before pursuing other problems as an unregulated level in the float bowl will mess up any jet/idle screw/needle valve adjustment. IOW a waste of time to adjust to 'whatever' the fuel level is in the float bowl AT THAT MOMENT. Fix the float valve if it is failed.
I figure the 'new carb' is after replacing the fuel enricher??? Not to clear on the sequence of events.
Either way, the engine should 'spring to life' within a few seconds of cranking, like RIGHT NOW. If the carb is good, has no plugged passages or jets, and adjusted, AND the valves are adjusted, AND the fuel is fresh, AND the spark is good, AND the spark plug is not fouled, AND the cam chain was timed properly, AND the valves are adjusted to about .004-.006", AND the valve seat/face are not pitted or corroded or covered with carbon chunks, AND the rings are sealing giving good compression, it should fire right up. And they do.
Really, if the above is set, the engine will start within one or two seconds of cranking. They will...
tom

[micscience]

I did leave some info out I thought I was making the post to long. The carb is definitely clean the valves are exactly at .003 on both valves a .004 feeler gauge will not fit I double checked two days ago. The manual says to adjust at .002 but I set it to .003. I honestly think the valve adjustment is exagerated if it is off by 1 or 2 thousandths from my experience.

I did replace the fuel valve with one I had on hand. I sucked in air to see if the valve was working and I could hear it open but I couldn't hear it close. From all the valves I have apllied vacuum to I never hear them close so Im assuming that is normal.

I don't think it is a matter of fuel not stopping because when I remove the line from the carb it doesn't flow when engine is off. It is quite possible there is no ventilation in the gas tank however I do have a breather line setup for ventilation coming from the tank.

Im going to drain the oil and inspect the oil for fuel mixed with oil plus an oil change is do and I am currently going to see if fuel isn't stopping today thanks for the suggestions.

By the way it was impossible to get a better video while holding the camera with one hand then aiming the flashlight at the valve while holding the brake down and pressing the starting button all at the same time. The point of the video was to show the symptom of most likely fuel coming out through the valves.

[KSR Moto]

This is a classic exaple of clutch bearing failure causing the starter motor to struggle while trying to turn both the engine and the wheel

I have came across this problem a couple of times, could also be a weak connecrion or bad starter relay

Have you overfilled it with oil?

[micscience]

No I haven't over filled it with oil.

I ordered new fuel valves first I ordered this one: www.amazon.com/gp/product/B079LZXKFF/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

and a second for good measure with manual shut off and no vacuum input so fuel is flowing at all times unless manually shut. The first fuel valve took a long time to start the scooter and it would die immediately. So I added the manual petcock one and it started up right away. It started drizzling so I didn't get a chance to fiddle with it and see if it wasn't a fluke.

It kills me how many times I buy scooter parts and they don't work off the shelf. I could never recommend a chinese scooter to someone who isn't mechanically inclined. I would be surprised to see a Chinese scooter last two years with no problems from from a brand new stand point. Shoot maybe even one year.