scoot only starts after draining carb

[bull]

Skyrider, you are correct that a petcock can starve an engine for fuel, especially if it is stopped up. the filters in some fuel control valves are inadequate, especially in light of some of the additives people use that are up to 30% ethanol, which can destroy the filter in it and attack the tank coating.

I prefer testing, and repairing rather than just swapping parts, so with the latest information bluefire shared about his SD BBK, the next step for me would be to check the compression and valve adjustment.

[bluefire808]

I just redid valves and have kept up on them regularly. Do u recommend any compression test tools/brand or website u would use? I have never done a compression test

[bull]

my choice for tools is SnapOn, Mac & Cornwell, they are too expensive for hobbyist or casual users

there are plenty of videos on youtube showing how to do the test

[tcthomp66]

Thinking you might also check the air/fuel screw. I'm currently working on an issue with the air/fuel where it will either run or idle at start, but not both. If you have access to the screw, try setting it to 2-2 1/2 turns out, and see if it will idle at start. Then give it some gas and see if the engine actually revs up or bogs down.

My theory here is that you may actually have an air/fuel mixture issue. Try the petcock first (they're about $4 on Amazon), then check this. Good luck.

[bluefire808]

I tuned my air/fuel a few days ago which solved my starting issue. Now it just randomly dies.. compression test snd petcock are my next tasks