Running problems Husqvarna 246 and Shindaiwa 457S probably bad fuel issues

[ellinghamso]

 

 I have an old Husqvarna 246 and a Shindaiwa 457S which both start with some effort and then die in a few seconds, stall if I try to rev up. Both carburettors cleaned and fuel filters blown with compressed air through fuel hose. Both have been running a couple of months with 2 year old fuel, some over rich (4% oil). I now suspect clogged spark arrestors, but can't find a mesh on either. Tried to split the Husqvarna muffler, is it supposed to come apart? Anyone able to help?

[Air Lad]

Obviously some fresh fuel. Mabye some fuel additive that can clean the system if they will run.
You could see how they go without mufflers for a bit to eliminate the clogged arrester theory.

[hedgerow]

Your gas must hold up better than mind does. When my gas has been around more than a couple months I notice my saws get hard to start and don't run at there peak. If its more than a month old I just put it in the pickup and start with fresh. I try to time my cutting so I don't end up with almost a full can of mix if we are not going to be cutting for a while. 

[lxskllr]

Where are you located? You may not have spark arrestors. I believe they're unique to the US, at least in year's past. It'll most likely be one of the last things before the exhaust hits the atmosphere, so if it exists, you should be able to see it with the muffler installed on the saw. It's also a maintenance/replacement part, so I wouldn't expect it to be hard to get to if you have one. You might need a carb rebuild, especially if it's sat with corn gas in it.