Jules Richardson wrote:
....

... Don't think I have any carb cleaner, although I do
have some brake parts cleaner - maybe that's asking for trouble, though!
(I'm not sure how similar it is)

Close enough; anything highly solvent that evaporates cleanly will do...

Then start over with a dry, clean, gas tank and lines. Fill with gas
that you bought within the past month.

Yeah, the gas lines/filter are another possibility I suppose - as I said,
it seems to get good flow from the tank, but I've heard of rubber hoses
essentially delaminating and collapsing internally when they age. As a
test I suppose I can ensure a clean tank and try without a filter (I
think I have some spare new hose somewhere of the right size)
....

These small engines if the hose flows it's not the problem. If there is
a filter (many don't, that is a possibility--the w/o it test is easy to
eliminate the possibility of course).

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