Stihl 026 wont idle and surges at mid throttle

[GlenDeep]

Hi: New to this forum so hope I can get some help. Traded my small Husqvarna for my brother's non-working Stihl 026. Tore it down (complete disassembly - just for fun) over the winter and rebuilt it with new carb kit and other bits and pieces. Started it in the spring and it worked fine, at least under no load (nothing around to cut!) and it would idle just fine. First major job at the cottage this year and it started out fine but then would not idle (would still run and cut at WOT). Tried all sorts of adjustments but will start and run (and cut) at WOT but as soon as throttle is relaxed it starts to surge and at low throttle it dies completely. Brought it home and took out the fuel pick-up hose and found it partly split (it was an old hose so may have split when I removed it). Put in new hose but the saw runs exactly the same - will start and run at WOT but surges at mid-throttle and dies at idle. What next? Open up the carb again?

Any help much appreciated. Back to the cottage today so will be a few days before I am back on-line.

Glen

 

[AKDriveSprocket]

Sounds like the saw needs to be pressure and vac tested.

 

[Whiskers]

Check the impulse line and intake boot for cracks, if the fuel line was cracked those will be next.

 

[nstueve]

yep... air leak is causing lean condition causing saw to rev unexpectedly.

on an 026 If your lines are good I got $25 that says the flywheel side oil seal is leaking.

 

[ncfarmboy]

yep... air leak is causing lean condition causing saw to rev unexpectedly.

on an 026 If your lines are good I got $25 that says the flywheel side oil seal is leaking.

Bingo!!!!
Shep

 

[Frogfarmer]

The split line may have let trash into the carb but those symptoms are very common for an air leak and the crank seals are known for wear. Best to tear down and replace seals and impulse line. You will get to know the saw a little better and one step closer to a reliable saw.

 

[zogger]

You cleaned the carb once, but then reused the old cracked line, so ya, it sucked up dirt. It can move enough fuel to sorta run, but not reliably under load.....

Might be other issues there as mentioned above, but I would look there first, new lines/filter/carb cleaning. New crank seals maybe, other potential leaky areas.

 

[GlenDeep]

back in business

Sorry for taking so long to reply. Have been busy at the cottage putting in a septic system (old age, eh). Took the saw into the local dealer and yes, it was a crank seal (clutch side) and a dirty filter. $100 (including a sharpen) has put it back into business. My wife has taken to pointing out flyer ads for new chainsaws for $200. Still haven't convinced her that my old Stihl is worth twice as much as that new junk (sigh). Thanks for all your help.

Glen

 

[psuiewalsh]

Sorry for taking so long to reply. Have been busy at the cottage putting in a septic system (old age, eh). Took the saw into the local dealer and yes, it was a crank seal (clutch side) and a dirty filter. $100 (including a sharpen) has put it back into business. My wife has taken to pointing out flyer ads for new chainsaws for $200. Still haven't convinced her that my old Stihl is worth twice as much as that new junk (sigh). Thanks for all your help.

Glen

Isin't the 261 like $600 something in Canada? Show her that ad.

 

[rocketnorton]

Isin't the 261 like $600 something in Canada? Show her that ad.

it is...

 

[rocketnorton]

Sorry for taking so long to reply. Have been busy at the cottage putting in a septic system (old age, eh). Took the saw into the local dealer and yes, it was a crank seal (clutch side) and a dirty filter. $100 (including a sharpen) has put it back into business. My wife has taken to pointing out flyer ads for new chainsaws for $200. Still haven't convinced her that my old Stihl is worth twice as much as that new junk (sigh). Thanks for all your help.

Glen

did they do both sides?

 

[GlenDeep]

Thanks again

Yeah, will definitely show her the ads for the MS260 (I think that is the current equivalent to my 026?). As for the seals - the dealer only changed the one because the damn fool (that would be me) who put new seals in over the winter apparently installed one of them incorrectly so the other one was still brand new.