My Scooter has me scratching my head.
 

The problem I'm having is that my scooter died one day while I was out riding and I couldn't start it. I have been trying to diagnose the problem with no luck. I've replaced the cdi, carb, sparkplug, sparkplug wire, stator, volt. reg, and the fuel petcock. I even tried to adjust the valves. Still no start. It has to be something simple. The engine is only so big. lol. I don't want to give up on the engine. I have a 2012 velocity 150cc. I came here to see if anyone can help me out. Attachment 947

How long has the scooter been sitting idle before the day that it died just a suggestion but check that battery a battery tender is a good idea if you're scooter spends any amount of time without you starting it every few days etc..

I was driving it daily at the time. My truck was in the shop so it was my daily driver. It was running good up until it stalled when I was riding one day and never started back up. I adjusted the valves after to see if that helped. I didnt replace the valve cover seal. I think that air might be escaping from the valve cover because of there being no gasket. Im gonna put some gasket maker on it to see if it helps any.

Fuel, spark, air... that is what it takes to make it run. If it ran fine up until it didn't, then messing with the valves was probably unnecessary. Many times it is a fuel delivery issue; that could be a blocked, clogged, pinched or kinked fuel line, clogged fuel filter, defective fuel pump (or blown fuse), closed or plugged fuel petcock, some problem in the float bowl, clogged carburetor jet, possible engine flooding (Too much fuel) or simply something as unexpected as water in the tank or a batch of really, really bad gas.

Spark may be weak or inhibited by bad or weak battery, weak or faulty ignition coil, bad spark plug, faulty spark plug wire or connector, defective stator, defective voltage regulator/rectifier, faulty ECU, loose connections, faulty connections causing grounding.

The air situation most often applies to problems with keeping the engine running or very rough starting; that is, some engine firing does occur, but the proper combination of fuel/air is not happening well enough to start and stay running.

Start with checking to see if it is getting fuel to the carb.
Then check to see if there is spark and that it is strong enough make it fire.

It's not often that both fuel and spark fail at the same time. But it could with a grounding or fuse issue that would prevent the fuel pump AND ignition from working.

There is more I'm sure, but start with the basics of going from most likely and least complicated or invasive before going on to the more complicated and technical stuff. Being methodical and thorough should get you where you want to be in your search for the source and solution to the problem.

Thanks for the reply. I've replaced the carb, spark plug, stator, rectifier, spark plug wire, ecu, vacuum petcock. I know it's getting fuel to the engine because the spark plug is wet when I take it out. I think My scooter only has one fuse and I changed that. I even changed the gas.

Replace the batter and see what happens.

Have you verified there is a good strong spark? Just throwing parts at the problem isnt going to fix it. If your getting good spark, good fuel, then the next step is to check to see if the flywheel key sheered off, which throws the engine's spark out of time. And not amount of parts is going to fix the timing if the key is sheered off. Its a tiny alum key that keeps the flywheel in a precise spot on the crankshaft. Check that and report back to me. I am a professional small engine mechanic. The flywheel key is your next place to check, going by what you have done and if you have verified that you are getting a nice strong spark. Mike