My cheapo Gardenline 16" chainsaw has saved me a heap of money in firewood since I bought it a couple of years ago but something seems to be fecked in the chain tension adjuster.

There's a large knob that you wind to move the bar in and out for adjustment but now no amount of twiddling advances the bar. I suspect the teeth between the knob and the gear that turns the adjustment shaft are stripped.

Is there any likelihood of this part being available as a spare (or as part of the whole chain retention/chain brake assembly) or should I just cut my losses and buy a new one?

It doesn't owe me anything but it starts and runs well so I don't like the thought of just ditching it.

So far I've failed to find a part like it online for sale.

Tim