I added an extra rubber washer to the top because sawdust was coming around that and looked like it was getting around that foam seal. I think when people say fines are getting through specifically they are referring to it getting under the bottom of the filter I've seen that personally even with the additional washer providing that downward pressure but as you say it seals next to the stack people can say all day long that a phone filter breathes better. I remain unconvinced of that but regardless that's where the complaint is stemming from. I do clean my filter every few tanks it is definitely necessary with this saw. It really fills up fast.
Fines come in from the top, the foam washer compresses over time and doesn't create a good seal. There are many videos on this and people putting additional rubber washers under the foam washer. Mine had fines inside so I added one.
Bubba, before you say how great that filter is, run about 10 tanks of fuel through the saw and you will see the fines that get past the filter, they come through the foam washer on the locking pin, to remedy this use one foam washer behind the filter and one on top side of filter, Stihl sells a pre-filter for the hd 2 filter, a little filter oil on the pre-filter helps a lot, when you blow the filter out with compressed air you open up the paper element and you physically can't see it, I have three of the 500 I saws and 2 of the 661 models they all have the same glitch with the hd 2 filters.
The 500i and MS661 use the same filter. It does not work in any other saws. If stihl would have used the HD2 filter used in the older saws like the MS660 with a threaded stud and srew on nut both the 500i and MS661 would not have the filtration issues they have.
That's exactly how I see it too! Stihl in Germany pays a lot of expensive engineers to ensure the quality is right. Many millions of euros are invested in development and then a West Coast Saws and "Max Airflow" or Egan Performance with a foam filter is supposed to be better? I don't believe that! It looks like they want to make money with it!
Interesting. I think I got a bad filter. The original filter did not hold like that at all. Wish I would’ve known how it is supposed to be. We did have a bunch coming from the top but that’s an easy fix 100 different ways. Nothing against MaxFlow, we’ve had zero problems and the fit is great. A stain brush and/or air nozzle , and/or shop vac are a lot easier than washing and re-oiling a foam air filter. And I’m curious which filter flows more air.
