Chainsaw Repair

Another thing too that I've found with the Dolmar HD filters is that in drier, dustier wood the prefilter blocks up very quickly causing erratic running. I had both of my 7900's start showing signs of this while felling. The fix was to remove the pre filters and they've been fine ever since. I'm not yet convinced they are needed as nothing has got past these filters yet, even dead Red Gum which makes most filter systems look pretty average.
I believe the Dolmar HD systems are one of the best on the market along with the newer Stihl HD2 setup.

Here is a photo below of the difference in surface area between a Dolmar HD and Husky 390XP HD filter. I actually gutted a Dolmar HD filter and epoxied the paper element into the Husky housing. I don't have to oil the filter anymore and no more dust has gotten into the Husky since