Stihl 026 not running propper

[merc_man]

Buddy of mine has a 026 that just dont seem to run right. It has had new intake boot, seals, fuel line and impulse line.
They tried a carb kit in the oem carb. Tried a chinese carb. And it just dont seem to hold a tune. Can get ot runni g great then few cuys later it runs crappy again. I did have it hear and tried it last year. I holds preasure and vac. If I can remember rite it had about 150 psi compression.
New spark plug as well.
Any help appreciated. Thanks

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[timg]

Not being a wise guy @merc_man. Did you pull the spark arrestor screen and retry??

 

[Kiwioilboiler]

Following. I have an 024 with a WT-22b that's proving stubborn.

 

[Duane(Pa)]

Try it without the air filter on.

 

[Kiwioilboiler]

Try it without the air filter on.

Choke flap is in the air-filter in mine, and on choke seems only way to get mine going. Any thing in particular we are trying to prove by trying to start it without the filter/choke?

 

[merc_man]

Not being a wise guy @merc_man. Did you pull the spark arrestor screen and retry??

Forgot. Muffler has been modded same as my 026 muff.

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[BuckthornBonnie]

Proper functioning of the choke flap during running conditions.

Is it going lean and then pig rich? Check that air filter.

I’ve found 1121s run better with OEM air filters and the larger fuel filter with the S-shaped line.

 

[merc_man]

My BIL lives down the road from him. He is gonna grab his saw in the morning and put his carb on it. He also has a 026. Will tell him to switch air filters to just to rule that out.

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[Duane(Pa)]

Choke flap is in the air-filter in mine, and on choke seems only way to get mine going. Any thing in particular we are trying to prove by trying to start it without the filter/choke?

Yes, you will have to choke the saw to warm it up enough to start without filter. The choke flap spring is really the weak link. It is possible that it has inadequate tension and the flap is being partially sucked shut at high RPM. Since there has been a second carburetor tried, my next suggestion is probably moot. The worst tuning problem I have ever had with an 026 was caused by excess buildup of fine sawdust under the metering diaphragm cover. It had a breather hole in it, and allowed the whole cavity to become filled with fines...

 

[tickbitintn]

I ran into the choke flap being sucked closed once the saw warmed up...
I think mine was an 028 though if I remember correctly.

 

[angelo c]

since your BIL is going with the other donor saw. swap out the coil after all the other swappages... had a funky 7500 redmax blower with a bad kill switch...had a bear of a time chasing electric continuity...turned out the coil was "open" and the weak link. coils is some funny bishes

 

[Wood Doctor]

I have to go along with Angelo C on this on. The problem at this point is likely electrical in nature. You've done about everything else to get this saw going. You would be surprised to discover how many engine problems I have encountered that are caused by electrical failure of some sort -- switches, wires, coils, connectors, etc.