G'day,

Thanks!

I've just come in from having a start and run test and shining a torch down inside the fuel filling point (with cap and retainer clip removed).

I hadn't ever removed the tank filter line assembly as, due to the low usage of the saw and good 'fuel hygiene' practices and high quality 2-stroke oil I now use, I didn't think it was warranted. It certainly looks clean enough on the outer surface of the sintered plastic cylinder and there are no leakages around the grommet.

However, it seems that you came up with a stroke of genius! Having been used to seeing filter units flop around inside the translucent tanks of line and hedge trimmers, I had assumed the same for this, despite the black opaque plastic that the tank is made from obscuring the view. If you look inside from the right hand side of the saw with the torch, the grommet is up on the right ceiling of the tank (i.e. toward the back of the saw) and its internal tube sweeps down and toward the left (the front of the saw). Over to the left of the tank ceiling is the primer circuit return line 'spigot' which protrudes slightly into the tank also. The filter had become wedged in behind this somehow, and although nominally level, it probably was sitting about 4-5 mm above the 'floor' of the tank, which isn't completely flat anyway, but has a sloping section on that side..It was obvious the filter had become stuck as I couldn't shake it loose by gyrating the saw, but had to use long nose pliers to free it up.

Hmm. that suggests poor design strategy, but also the inner Tygon tube segment might need to be a bit shorter. Anyway, due to your insight I now know how to fix this if I see it happen again. Meanwhile, the priming action has removed most of the air pockets, and after starting and idling, I notice no bubbles now in any of the fuel lines.

I believe I do have another residual problem with the release of trivial amounts of 'scale' deposited inside the carburettor (engine version of kidney stones 'dissolving' - I can tell by listening to the engine tone while slowly revving the idle circuit after tuning the mixture,, but I've been working on this issue for a month or so, and finding the problem has decreased exponentially with regular running and paying attention to using clean, very fresh fuel. So for now anyway, all is looking good!

Thanks heaps for your expert evaluation!