Didn’t time it but as far as the tach goes it seems to hold a bit better rpm under load and has a touch more trigger snap. I didn’t go nuts with the muffler so it’s not much louder than stock either just different tone. Watch the video of it back a few posts to compare. Same log same chain.
Great saws. Check to see if you have green or black oil lines. The green is the old style that shrinks and then leaks and puts less oil on the bar. Nate can hook you up with the updated lines. OEM 7900 top end with HD filter are good additions as already mentioned. Mine, running that same config, has been rock solid for 6 yrs now.
The HD filter can drop rpm and power. It's not the filter that restricts airflow but the sharp turn in the new intake that is required along with the HD filter.
Is there a way to mod that bend a little to ease this restriction, or would you say the standard filter is better for power?
I don't think anyone has come up with a work around for it. Of the two stock choices the standard filter makes moar powah.
Hmm. I think I'll need to get the HD filter for my 6421 and take a gander. I've been known to wield a Dremel and do plastic/rubber modifying.
What’s the big benefit to the HD filter set up? Just a better filter than the little plastic loose fitting screen one?
From Bailey's. "Heavy duty air filter kit from Dolmar. This kit greatly increases the filter surface area, which gives the saw better air flow and longer runs between filter cleaning. Fits the following chainsaws:" But if there's a restriction, how's that helping?
The HD filter is gooder for the fines you'd typically run into with seasoned hard wood cutting and cutting with a dull chain. I've had my 7910 for a couple years now and never really saw the justification for the loss of power with the HD set up. I'd cut with it awhile and see if you are noticing a lot of fines getting past the stock filter and go from there.
