Stihl 026 Hard to start

[Bl8tant]

My neighbor brought over an older 026 that had been in his brothers shop for awhile and asked me to bring it back to life.

The saw was DOA due to burnt piston (impulse line had cracked and they continued to use it until it seized)

So I replaced/repaired/inspected:
New Piston (aftermarket)-saw has great compression now and my shoulder can vouch for it.
Cleaned cylinder
New impulse line
Pulled fuel line and it looked fine so I re-used it
Carb kit (except for inlet needle-the one in the kit was not correct, but all the other parts were a perfect match.)
Vacuum tested (seals are perfect - held over 15inHG with NO leakdown)

After getting it all back together, I cranked and cranked and cranked. FINALLY got the carb primed by slightly pressurizing the fuel tank through the vent hole and it fired right up. Idles perfect, runs great in the cut. One pull starts when warm.

So I let it sit overnight, went to start it......crank, crank, crank. I was just about to give up when it finally took off. Ran great, cut great, idles great, one pull to start when warm.

Anytime the saw sits overnight it takes 30 or more pulls to get it going. Once started and warm, it's perfect.

What the heck is going on. I've tinkered til I'm ready to pull my hair out. My shoulder can't take much more pulling. HELP! What am I overlooking.

FYI-I've tried multiple starting sequences, and the only way to get it started is to choke until it fires, leave choke on for a few seconds until the saw starts to smooth out, flip off the choke and let it run for a few more seconds, then goose it and she's ready to go. Choke+holding throttle=no start. No choke+holding throttle=no start.

It seems strange to me that the saw is able to run for awhile with the choke on when it's cold. My saws (024, 290, 020, and an Echo 330T) would just flood out if you left the choke on after it pops.

 

[Mastermind]

A few ideas for you to try. Open up the low speed jet a little. Re check the metering lever height, if it's too low it could make it act strange. Also, make sure the throttle linkage is opening the throttle when the choke is on. If you took the throttle butterfly out, it may need to be adjusted so the notch is in line with the idle holes in the carb body.

 

[Saw Dr.]

Either the choke flap is not closing the whole way, or the pump diaphragm and gasket are reversed in the carb. The pump diaphragm should sit flat against the block f the carb, and then the gasket. If this is right, then you are up against that crappy choke setup. I never did like those. Quickest way to test that is to remove the air filter and hold your thumb over the carb venturi. While holding your thumb there, give it a few quick pulls on a cold start and I bet she fires right up. You'll need to figure out where the slop is in the system in order to get it closing properly.

 

[Bl8tant]

Mastermind:
I didn't remove the butterfly, so I am assuming it is correctly positioned. The way the throttle and choke are set up on this saw, the throttle is not activated by the master lever. Only the choke. I will take a closer look at the setup. Maybe something is broke/missing.

Saw Dr.:
On the pump side I put the diaphram against the carb and the gasket on top of it. For the metering diaphram and gasket, I put the gasket on the carb and then the diaphram.

After looking at the parts diagram, I definitely need to take a closer look at the master lever setup.

Also, shouldn't the carb maintain prime overnight? This saw acts like the fuel drains out of the carb after sitting overnight.

Thank You for the replies!

 

[lone wolf]

Vac/ pressure test in order

 

[1steve]

Since you mentioned you had to pressurize tank to get fuel and said runs with it choked it sounds like an air leak so i would vacuum/pressure test to verify.
i know you vacuum tested and passed but did you pressurize?? Also inlet needle leaking could cause fuel to leak down overnight, you might want to replace with correct one. Hope this helps keep us posted.

 

[redoakneck]

Sounds like you have a work saw that needs to be run 24/7, so just keep cutting LOL

I have an 026 and 30 pulls would flood it if it was getting the gas. 3-4 pulls full choke, no more!! Then 3-4 pulls with the master lever flipped up. It usually starts then, if not, 1 pull full choke and 1 pull flipped up.

After I rebuilt it it only took 8-9 pulls to fire.

I agree, you must have a leak!!!!

 

[lone wolf]

Also double check the fuel line with vac tester.

 

[Bl8tant]

Well I think I figured it out. Since I was SURE that there was no air leak (re-tested everything including the fuel line) and the saw ran great once started, I decided to really give the choke/masterlever/linkage a real close inspection. At first I didn't notice anything. But after looking at the master lever on my 024, I realized that part of the lever that makes an "L" shape to hold the throttle partially open during "choke" and "start" was broken off.

To test I acquired an "assistant" to pull the cord while I held the throttle slighty open. Sure enough, after a few pulls on "choke" it popped. Moved the lever to the next detent and held the throttle slightly open (just like the missing tab would), and it fired right up. Problem solved....maybe.

I still need to let the saw sit overnight again and then see how many pulls it takes to get it going after a new master lever is installed. If it still seems hard to start, I will get a new inlet needle since the one in the kit was not the right one.

Thanks for the replies and everyone's input kept me from giving up and heaving the darn thing over the hill.

 

[Kogafortwo]

Well I think I figured it out. Since I was SURE that there was no air leak (re-tested everything including the fuel line) and the saw ran great once started, I decided to really give the choke/masterlever/linkage a real close inspection. At first I didn't notice anything. But after looking at the master lever on my 024, I realized that part of the lever that makes an "L" shape to hold the throttle partially open during "choke" and "start" was broken off.

That makes sense, especially after your other post where you said the lever operates choke only, not throttle. I think all Stihl master control levers do both. My 026 does as well as the 028 and the 440 Mag I sold off to a friend.
Glad you got it going.

 

[Bl8tant]

I felt pretty dumb not recognizing the potential problem sooner. I just thought that maybe some older 026 did not use the master lever to activate the throttle. I should have known better. I really hope this takes care of the last bug. The saw runs great and actually makes me think I'd like to add an 026 to my saw lineup.

 

[fearofpavement]

I really like my 026 and use it more than any other saw. Seems good for most of the cutting I do. I have an 18" bar on it.

 

[Asok Asus]

But after looking at the master lever on my 024, I realized that part of the lever that makes an "L" shape to hold the throttle partially open during "choke" and "start" was broken off.

To test I acquired an "assistant" to pull the cord while I held the throttle slighty open. Sure enough, after a few pulls on "choke" it popped. Moved the lever to the next detent and held the throttle slightly open (just like the missing tab would), and it fired right up. Problem solved

I know this is an old post, but thanks for making it! Identical symptoms, issues, and "tests" on my 024, and sure enough the throttle tab was missing from my master lever! Ordered a new one for $9.00.