49cc starts when it wants?

[HoosierDaddy]

Please help? I got this scooter back about two weeks ago with start up problems, sluggish run , top speed about 25 and stalling issues. I noticed right away dirt in the fuel filter, so I changed that, still not right so I changed the carburetor. Still no luck, Spark was good, then tried compression test... which came back 60 psi.

So since customer was a little frustrated (only 165km) on the scooter, I ordered a 100cc BBK thinking that could make up for things since she had a desire for more power... anyway put that in then I was getting random spark still hard starting.

Now I started on the spark issue, I replaced the coil with a high performance coil, same issue with sometimes a spark sometimes no spark... I changed the cdi, no help... so I started to pull the stator, but then I noticed the ground from the engine was loose. I tightened that up, now I have spark, but it is still hard starting... will start when it wants too?

I have also checked fuel delivery by sucking on the vacuum from the petcock valve and disconnecting the hose from the carb to make sure I'm getting vacuum. I even drained the gas and added new gas, changed the oil, and put in a new spark plug.

Oh yeah, the kill switch, start button, and battery seems fine.

Sorry for the long post, but please help?

I do get it started randomly, runs great, idles great, works great till I turn it off and try to restart? ugh!!