My new (old) Stihl 026 idles fast/slow depending on vertical/sideways. Normal?

[777funk]

I notice the idle speed changing depending on saw position. Is this normal?

 

[fearofpavement]

No, not normal. Usually indicates bad crankshaft seals.

 

[Saw Dr.]

My $ is on the flywheel side.

 

[777funk]

Thanks guys. If the bearings are still good can I get by with just new seals? What about just pulling the engine apart and putting a small bead of high temp gasket sealant between the bearing seals and engine block?

Other than this, seems like the saw runs and idles well. Never kills and I have it adjusted to just barely 4 stroke at high revs under load.

 

[SEAM]

Yo also may want to check the impulse hose. Turning the saw while holding it by the handles will deform the hose somewhat and may cause the same symptoms if there is a tiny hole or crack in the hose.
Besides the crank seals I would also check/replace the fuel and impulse lines and the carburetor diaphragms just to be on the safe side...

 

[777funk]

I cleaned the carb and the diaphrams looked pretty good (didn't run and plugged good when I got it). I also pressure tested the fuel line and it looked good. I'm not familiar enough with Stihl to know how to get the carb plastic housing off to get to the engine side of the impulse line. Couldn't figure that one out. I put a dab of grease on the impulse tube and pulled it over and it did suck in the grease dab. But I guess that wouldn't show just a pin hole would it. I didn't check the bearing seals. I'd seen a chain saw builder named Brad Snell(sp)? find a bearing leak with soapy water sprayed and bubbles. Maybe that'd be the way to check it. I'm not sure how he pressurized the crank case. Maybe airline to the impulse tube?

 

[SEAM]

The clutch-side seal you can easily check by having the saw idle with the chain/bar and sprocket cover removed and spraying some WD 40 or other oil around the clutch drum. If the engine speed drops (or changes) you've got a leak there. Same goes for the impulse hose (which can be removed easily after removing the rear AV mount bolts pull off the crank case connector and then pull out through the carb box).

PS: In my experience the clutch-side seal usually starts to leak first...

 

[777funk]

Started the saw and sprayed WD-40 near the starter area and clutch area with no change as well as near the impulse hose.

The change in idle depending on position is VERY slight but it's definitely there. I'd guess a 300RPM difference depending on vertical or horizontal idle. Other than this all seems normal. No problems with revs staying up etc.

 

[Stihlofadeal64]

My $ is on the flywheel side.

I work too hard for my money, but if I was to make a wager we would be standing side by side...

 

[777funk]

So looks like I pull the clutch and pull the flywheel and out they come?

I've pulled both on other saws. Do these apply?

Flywheel: loosen nut to a little above flush with crankshaft end, pry up slightly on flywheel with screwdriver and tap on the nut/crank until it pops loose.

Clutch: fill cylinder with rope to lock it up, knock the clutch CCW with brass punch and hammer.

I know there are special tools but assuming no special chainsaw specific tools exist (since they don't in my garage).

 

[Saw Dr.]

The clutch-side seal you can easily check by having the saw idle with the chain/bar and sprocket cover removed and spraying some WD 40 or other oil around the clutch drum. If the engine speed drops (or changes) you've got a leak there. Same goes for the impulse hose (which can be removed easily after removing the rear AV mount bolts pull off the crank case connector and then pull out through the carb box).

PS: In my experience the clutch-side seal usually starts to leak first...

Also my experience on other saws, but on 1121 series Stihls, it is almost always the flywheel side. Good practice to change both in any case.

 

[blsnelling]

Does it idle at normal RPMs, or is it high and won't come down with adjustment?

 

[777funk]

No it actually idles great (as far as I can tell anyways). No trouble with coming down from revs. Everything seems good but there's a slight change in idle speed when the saw is turned on it's side (slows down).

Here's a quick clip of it running:



Got this saw from a real nice older guy as non running for $65. Gave it a carb clean and it runs as you see in the video. I was pretty thankful for the deal. The chain is trash and the bar was an extra out of his junk box and well used but... it's my first Stihl! The piston is in good shape.

I have to say I was a bit disappointed that my Poulan 3314 with an Oregon 91VXL will cut circles around this 026 with some slow unknown chain on it. But that will change when I get a good chain on this one.

 

[blsnelling]

That to me does not sound like a cut and dried case of a bad seal. When the flywheel side seal went out on my 260, the idle was high and could not be adjusted down. I suspect that you may simply have fuel pooling, and no real issue at all. Of course, a vac/pressure test would answer that.

 

[blsnelling]

 

[777funk]

That to me does not sound like a cut and dried case of a bad seal. When the flywheel side seal went out on my 260, the idle was high and could not be adjusted down. I suspect that you may simply have fuel pooling, and no real issue at all. Of course, a vac/pressure test would answer that.

Thanks Brad, also excellent videos! I've seen a few of yours just in searching. Great work!

Fuel pooling, what does that mean? Sorry if that's a newb question.

 

[Frank Boyer]

Thanks Brad, also excellent videos! I've seen a few of yours just in searching. Great work!

Fuel pooling, what does that mean? Sorry if that's a newb question.

Do a muffler mod and that will wake the saw up. Pull the cover and make holes above and below the existing hole. Then check the carb adjustment.

 

[Red Amor]

Gday Brad
Mate for those that don't have the proper tool can you show us or suggest another way to remove the seal ? thankyou

 

[777funk]

Gday Brad
Mate for those that don't have the proper tool can you show us or suggest another way to remove the seal ? thankyou

I'm not Brad, but I did some reading on this because of my seal concern due to this thread. I've read that you can use a flat screwdriver with a notch ground into the side of the blade to hook the seal. For smaller saws smaller flat blade screw drivers were recommended. Also quality screwdrivers were advised. Cheapos had the notch break off. I'd think breakage would have to be affected tempering as well. Worth experimenting a little for what the Stihl tool runs.

 

[LegDeLimber]

At around the 40 second part of Brads video, It looked like the Garter spring was still on the crankshaft after the seal body came out.
IF my peepers aren't fooling me and it was still there.
I Just thought it would be a handy way to tell any first time seal swappers, to be sure and look out for that critter trying to stay behind and damage the new seal.

If Brad already covered that issue and my scatterbrain just missed that part, then everyone should just ignore me.