Saw cuts out at WOT

[tesart]

New to this sight and to tuning saws. Getting quite the education here... I think?!? Anyway the low idle on my stihl was too low and the saw would stop running with the throttle off. I backed it out a smig and solved that problem but now the saw cuts out completely at WOT. It still cuts fine with plenty of power as long as I don't hold the throttle in all the way. What going on???

 

[Lakeside53]

what type is the saw?

Sounds like you are staving for gas.. fuel filter? air leak in fuel hose?

More info...

 

[tesart]

I'm a bad saw owner, I'm not sure of the model #. 250 sticks in my head but I'm not sure.

 

[Lakeside53]

how about a brand? or a color?

 

[fishhuntcutwood]

lakeside, could he be too rich on the H screw? He says it'll cut fine if he's not all the way WOT, but then when he is, it dies. Is he flooding it out when he's got it WOT? Just curious.

And it was good talking to you on the phone yesterday. You sound like even more of a gentleman on the phone than you do online! Perhaps next time we'll be able to meet. I didn't get up to Bellingham until after six, and didn't get home until the wee hours this morning, but the Sun's out over here, so I might go do those trees...

Jeff

 

[tesart]

Its a stihl. At least 7 years old, with a 16 inch bar.

 

[fishhuntcutwood]

Is there a model on it? (And I guarantee it's not 311Y.) It should have a nameplate on top. If not, see if you can find a part number on a signifcant component. That'll get us headed in the right direction.

Welcome to AS.

Jeff

 

[tesart]

I'm not anywhere near the saw right now. but I thinks its something like 056 or 250, 256. I'm realy not sure. I'll check when I get home and post monday.
Do you think it had anything to to with the low idle adjustment I made?

tom

 

[Lakeside53]

lakeside, could he be too rich on the H screw? He says it'll cut fine if he's not all the way WOT, but then when he is, it dies. Is he flooding it out when he's got it WOT? Just curious.

And it was good talking to you on the phone yesterday. You sound like even more of a gentleman on the phone than you do online! Perhaps next time we'll be able to meet. I didn't get up to Bellingham until after six, and didn't get home until the wee hours this morning, but the Sun's out over here, so I might go do those trees...

Jeff

Too rich on the high would be unlikely to make it "cut out". With the throttle wide open, you can have just about any mixture (within reason) and it will chug along. Right now we're not sure if its an 025 or an 056... and that's quite a range!

Tesart : set both your L and H screws at exactly 1 turn out from gently seated, and test again...

Suns' out here, even though it is supposed to be raining and a windstorm this pm. Hmmm, best forecast may be to just step outside... Gentleman?? dang, and I aspire to be FISH...

 

[Lakeside53]

..and to answer your other quesiton, no, backing the LA screw out a Smig would not make the saw cut out at WOT - just drops the idle speed. If you're talkking about the L screw, then all you did was slightly enrichen the mixture at idle, and that would alo have no effect on the High end.

 

[tesart]

OK not to be thick here, but what does the LA screw do. I turned out the L screw.

tom

 

[Lakeside53]

LA is "Low Idle". It just "presets" the throttle opening. L is the mixture screw for the idle, and H is the mixture screw for the High speed running.

Try setting the L+H screws exactly one turn out for their seats, then fine adjustments from there. IN is leaner, OUT is Richer. If it won't idle at one turn out on L, then turn up LA a little to get started.

 

[tesart]

Thanks for the advice. I can't wait to get back out in the woods. Lakeside, get outside befor the sun goes down. Thies computers have a way of destroying a nice day.

Thanks Again, I'll be back,
Tom

 

[cbfarmall]

Tell you what, I've found myself adjusting the wrong screws from time to time. Turn the hi screw in too much, and the saw will never get enough fuel to even rev up. Like previously said, I'd reset the screws to 1 turn out and go from there.

Remember to set the idle mixture (L) screw so the saw idles well and also does NOT stutter or hesitate when you jump on the throttle.

Chris B.

 

[lostone]

Remember when you take the screws in all the way to be gentle and not tighten them just enough to get them in, then back them out.

 

[stihltech]

model

Had a cutomer looking for a used carburetor for his Stihl model 55. You know how HARD it is to find parts for those!

It was an 046 when he got there.

 

[tesart]

Thanks for all the help! It is a 026. I reset the H and L screw to one turn out and then richened the H a little and it is doing fine.

Tom

 

[tesart]

Turns out that the wire that goes to the kill switch had come loose and when the trottle was in all the way it ground out.

Tom

 

[Lakeside53]

sneaky!!!