150cc GY6 issues By jamesissopro (Read 684 times)

[jamesissopro]

First off, I don't have access to these boards from tapatalk, anyone know why?
Secondly, my GY6 is the 1P57QMU

What I've done.

The scooter ran fine, I was test riding it up and down my road. It then slowed down. It ran from then on but if I went over 25% throttle, it bogged and would stall.

I cleaned the carb after that, and it didn't bog anymore but it wouldn't go above 25mph.

The piston in the carb was getting stuck, so I cleaned again emphasizing on the piston and piston walls.

IT STARTS! I can feel the power has returned, so I take it down the road. SMOOTHLY cruising up to speed when it stalls at 35mph. =[

I get it home and find out the carb is flooding (It was draing from overflow, emptied the float bowl and tried startingg again until the carb overflowed again)

I took the carb apart yet AGAIN! and cleaned the bowl out a little better and tested the float system with carb cleaner, it works fine.

I put it back together and tried starting again, the carb no longer over flows but it won't start... wierd.

After I while I took off the fuel in line and plugged it, i cranked for a while and it eventually cranked on STRONG for a few seconds then stalled (obviously)

My theory was the cylinder was flooding. I believe I am correct because once I get to this point listed above, the motor will try to crank and I can hear it igniting and sometimes it will run with WOT at a VERY LOW RPM, and then eventually stalls and I have to repeat the above until I believe the cylinder is empty.

Any advice on this? I am very frustrated at this point. I have tried to let the bike dry and a similar thing happens until it, what I believe, floods.

[jamesissopro]

Just realized that I have fuel in my vacuum lines. My petcock is inline right before the fuel in, I am going to try and bypass it now and see what happens. Any other advice is still welcomed.

[Alleyoop]

Bypassing it for now is the only way and hope the float stops the fuel from overfilling and flooding the carb.
But whenever you suspect the chamber has been flooded take the plug out and crank it the fuel will blow out the plug hole.
Alleyoop

[jamesissopro]

Thanks for the tip alley, I will try that. I have managed to get it to start.

Just to clarify, the card does not overflow anymore, at least not to the overflow valve.

The ONLY time I can get it started at this point is if I remove the fuel line from the carb (Which is purely gravity fed at this point) and if I drain the carb. Then it fire up BEAUTIFULLY but only for a split second with a large puff of smoke and stall. (Obviously, since there is not anymore fuel to burn.) if there is ANY fuel down in the carb it refuses to start... Any other tips? I am going to go take the spark plug out and try and blow some gas out. Alley, if my scooter ran for that split second then stalled with no fuel supply in the system, wouldn't that mean I burnt any fuel in the cylinder? If so, why would the scooter not run if there is a fuel supply? The gravity fed fuel supply definitely is bringing down fuel, and the fuel is not overflowing the carb.

[jamesissopro]

This is REALLY frustrating me, The scooter will start and run at VERY LOW RPM with WOT with little to no gas in the carb and the fuel in disconnected. When it has just a little bit of fuel left it it actually revs up with me holding WOT with a LOT of power. The scooter jumps forward and then runs out of the remaining gas. Again, this ONLY happens when fuel is disconnected and most of the carb has been drained like only fumes are there. I removed the carb and tested the float. It works perfectly. When the float is fully lifted no fuel comes through the fuel in port. I removed the carb and the bowl from the bottom of it and tested it and it works perfectly. I am at a loss.

[jamesissopro]

Ok everyone, I opened the carb AGAIN to find the needle had come out, well I replaced and secured it and my scooter runs now!!! but guess what, read the first part of my story

"The scooter ran fine, I was test riding it up and down my road. It then slowed down. It ran from then on but if I went over 25% throttle, it bogged and would stall."

THE SAME THING THAT I STARTED OUT WITH IS HAPPENING NOW! I'm going to throw this thing in my trash can and let the dump truck come get it >.>

[Bashan]

If it is happening again you are not securing the needle properly against the slider bottom. There are titantic forces going on down there, it must be a stable config. Get us some pix?