Stalling after rpms dip below 3500-4000

[Mike Husting]

Just purchased my new vision, what causes the bike to stall after falling below 3500-4000 rpms?  You have to rev it to keep it going?  Once it hits 4000 rpms it is okay.  I have heard there was a carb jet problem and a fix might be out there?
Mike

[Lucky]

If by stalling, you mean just that, stopps running, then sounds like you have a big vacume leak, probably YICS canister leaks or a hose is off.  also plug the vac line going to the petcock for a test. if the petcock leaks you could be pulling air  OR fuel.
if that all checks out, then carb sync may be way off.

if by stalling you mean a flat spot when you crank the throttle, then you have a plugged or dirty pilot jet or passage.
--Lucky

[jasonm.]

I agree with lucky. I have seen a Vision start fine then die once the choke was off. And the throttle needing to be inputted to keep the revs up. It was the YICS or another vacuum leak every time.