150cc dies at 15-20mph

[baddley]

Hi

So I have a TaoTao Quantum 150 that has a bunch of mods done too it like a big bore kit, different exhaust, carb with a 30 mm intake that has been re jetted and nibbi extension with a UNI air filter on it.
The bike runs great on the kickstand and transitions fine and has a good idle too it. Top speed is great and has no problems at all. It actually runs good for a few miles than it's starts this issue. The problem is when u get down to about the 15 mph or so the bike shuts itself off and dies out. You CAN restart the scoot bike right away.

It does have a fuel filter up by the tank itself(stock location)and I added one on the main fuel line going to the carb too, both look good.

Things I have done already are:

1. Drilled a hole in the gas cap already to prevent vapor lock, since I had this problem when I first got the scoot
2. Checked the valve clearance are both set too .004
3 Zip tied the vent hose off of the vapor canister off and deleted the EGR from the head too
4 I also have played with the float bowl level in the carb and ended up putting it back in the original spot I found it in....
5. Checked the idle numerous times

Anybody have any idea what could be going on or what a remedy for me would be?

Thanks
Scott

[kz1000st]

Look for a vacuum leak. It sounds like it's going lean after warmup. A cracked intake manifold or a vacuum line could be the cause.