Hi Craig, welcome to the site.
Your flare is pretty and blue. But like JO says, a pre-mixed air/fuel flare will generally burn blue no matter what, and can lie to you about the gas quality. You want a straight pipe coming off the end. Turn the blower down until the flame stays attached to the pipe. Most of us get a purple-orange color that's hard to describe, but you know it when you see it. Eventually you won't need to flare-stare at all... experience and good gasifier design will keep your engine tar-free.
Yes it's easy to cook the vacuum cleaners. I would be extremely careful flaring from one, because if the flame backs up the pipe it will try to become a jet engine and go BOOM. Make sure the vacuum is sealed internally, any air mixing with the gas will dilute the flare and lead to the above boom.
That looks like a FEMA gasifier, correct? In general we don't recommend them for running engines you care about, because it's very easy to make tar. Great for playing with though, and you can certainly run an engine... just use a cheap mower or something to start off. You will probably mess it up.
Another long term observation... From your accent I'm guessing Canadian? Meaning cold winters. A wet filter/bubbler will only work during warm seasons. You'll have to look at some different filters for cold weather running.