There are a couple of things you might try. I don’t know what size
your smallest torch tip is, but if it gets dirty & you want to clean
it, you can get an assortment of torch tip cleaners at most welding
suppliers. They’re basically different size reamers that are inserted
into the hole in the tip. Inserting & removing them several times
cleans out the tip. You only use the size that fits the tip, if you
use a larger size you may increase the size of hole in the tip.
Another thing you might try is adjusting the regulator (increasing or
decreasing) the pressure the gas is delivered. This is done by turning
the knob/handle on the regulator attached to the tank.
A 3rd thing to check is the flame arrestor in the base of the tip.
Most tips for acet/air torches I’m familiar with have a removable
filter/flame arrestor in the part of the tip that screws into the
Remove a tip from the handle. Look inside the end that screws into the
handle. You’ll probably see a steel ring with a hex shaped hole in it.
At the bottom of the hex will appear something that may look like a
very fine screen or porous stone, this is the filter/flame arrestor.
The hex opening will accommodate an allen wrench, which is used to
unscrew the filter/flame arrestor.
I don’t know what the symptoms of a dirty or partially blocked
filter/flame arrestor are, but if it is removed from the tip, it can
be cleaned by soaking in a solvent that will cut petroleum products.
After soaking, clear the solvent out by blowing a strong air stream
through the filter. The other option is to buy a new replacement
filter at a welding supply.
The purpose of the filter/flame arrestor is to prevent the flame from
following the gas down the hose to the tank. DON’T use a tip that
doesn’t have one!