2 Stoke Bike idles but won't rev

[gc754]

I know this isn't technically a 49cc scooter/moped but its pretty close so I was wondering what you guys think.  I just got a 09 kx65 and just put a new stator and top end in it with a new Athena cylinder jug but for some reason it doesn't want to rev much past idle.  After the top end it only has 90psi compression which goes up to 130psi if I put oil in the cylinder.  I checked the ring gap and its ~.24mm which is within the .15mm-.35mm spec, so still don't know why its that low since its supposed to be around 180psi.  But I think 90psi should still be enough to run.  I've also tried 4 different carbs including the oem one and almost every jet possible, but for some reason, it will only run on choke for all the carbs unless I have an extremely large pilot jet in it. So I replaced the reeds with Vforce3s and changed the spark plug but it didn't change anything.  Thinking I have an air leak I leakdown tested it, but it held 10 psi and only dropped 1 psi over an hour and the only place I saw it leaking a little was my exhaust plug I made.  So I'm about all out of options and was wondering if you guys have had any issues like this with any small 2 strokes.  Any feedback or suggestions would be greatly appreciated. 

Video of it running: youtube.com/shorts/fmyRQ33237o?si=Agabtxcu9--j_u5g

[190mech]

Could be very late ignition timing.. Why did you replace the stator?

[gc754]

Aug 1, 2024 16:45:48 GMT -5 190mech said:

Could be very late ignition timing.. Why did you replace the stator?

I replaced the stator because the old coil was shot and was disconnected somewhere in the coil so it didn't generate any power and I had no spark.

[jodaddy]

Air leak could be crank seals. Any oil behind the stator when you replaced it? Does the exhaust smell like tranny fluid? When you whack the throttle does it do the lean bog bwaaaaaaa noise? Does that little thing have a apower valve? What’s the air filter situation?

[kosmos]

90 psi lost if thats a brand new cylinder, shows some big problem there. is the gaskets; head and base, the ones that came with the kit? Did the head come with the cylinder? sure it'll start, but idk about making it run very much with that low of psi any more past starting up.

running issue.. jetting? pilot jet, main jet, needle.

[bacon]

Check your squish and adjust gaskets as needed. 90psi is low...might start real hard and have low power if you run it. Throttle wide open (or carb off) when doing a compression check.