Hoosqvarna 261 issue

[Mpl127]

Think it’s fuel related, first it wouldn’t start, good spark and compression. Took carb out (carb is OEM original, and was kitted when I rebuilt a couple years ago), removed fuel filter (which is massive, like 1-1/2” long that I received as an OEM replacement) blew fuel line out which was replaced a year ago. Got the saw started and it would idle but erratic. Adjusted carb after running for a few minutes, settled in to a nice 2700 rpm range on the tach. Went out and started cutting and the carb would recover after WOT in the wood, but a blip of WOT under No load and it would die. Even before I started cutting, getting the saw to settle back to a nice idle RpM was erratic, sometimes it would, sometimes it wouldn’t with RPM staying elevated. That fuel filter caught my attention, none of my bigger saws have a fuel filter that large.

 

[hi5]

what do you mean by the carb would recover after wot? is it revving up and down in the cut, but revving fine at WOT under no load?

edit: sorry, read that wrong, what are your carb settings like? pretty standard number of turns out?

ive had eratic idle a few times and it was always due to an air leak

 

[Mpl127]

what do you mean by the carb would recover after wot? is it revving up and down in the cut, but revving fine at WOT under no load?

edit: sorry, read that wrong, what are your carb settings like? pretty standard number of turns out?

ive had eratic idle a few times and it was always due to an air leak

bench tested saw when I rebuilt a couple of years ago and it passed pressure/vacuum. What I mean by recover after WOT is that it goes low for a few seconds after WOT and then settles back to a good even idle, at least this is what I experience on my saws that run well. This 261 does that some of the time but not all of the time.

 

[J D]

No air leaks 2 years ago doesn't mean it isn't leaking now. Was fuel fresh? Had it been sitting with old/ethanol fuel?
I'd start by pulling the carb apart & if everything looks fine in there I'd vac/pressure test it before putting the carb back on

 

[Agrarian]

Bad recovery after WOT can be the main jet check valve. You didn't by chance blow this carb out with compressed air when cleaning it? That can destroy the valve mechanism in the jet. Then the only fix is to replace the jet.

 

[Mpl127]

No air leaks 2 years ago doesn't mean it isn't leaking now. Was fuel fresh? Had it been sitting with old/ethanol fuel?
I'd start by pulling the carb apart & if everything looks fine in there I'd vac/pressure test it before putting the carb back on

No on the fuel, only running the Husqy or stihl premix through it. Sure wouldn’t hurt to test for air leak again.

 

[Mpl127]

Bad recovery after WOT can be the main jet check valve. You didn't by chance blow this carb out with compressed air when cleaning it? That can destroy the valve mechanism in the jet. Then the only fix is to replace the jet.

Can’t remember if I blew out compressed air when I rebuilt, I’ll test that check valve. Thanks.