getting different info for a repair...

[DOJO]

Bought a used 026 some time ago. Main issues with the saw was that I dies right after to switch it to ON position.

There were some problem with one of the fuel hoses and piston with cylinder where scores.
Got a new fuel hose and a new piston and carb kit. honed the cylinder.
But still the same problem. It's very hard to start takes me 5 min to do so, but after I'm able to "start" it it takes one pill, but still died right after i switch it to ON.

Called Stihl, and been told it happens because I honed the cylinder.

Reading the forum, found that it might be flywheel side seals. But when I called a local dealer, he said it might be something else.

At this point, I'm just lost and confused

 

[Erick]

Sounds like a carb rebuild is in order (cheap and easy), and then a pressure/vacuum test to make sure everything else is doing what it is supposed to.

 

[secureland]

I'm wondering if it's something simple regarding your Black Choke Switch/Master Control touching the Contact spring that grounds the electrical and turns the saw off. You could check that easily.

Lately it seem there could be an entire forum dedicated to rebuilding, repairing 026's. Not that they are a bad saw, it seems they are a good enough saw for folks to spend some time on.


Bill

 

[SawTroll]

Bought a used 026 some time ago. Main issues with the saw was that I dies right after to switch it to ON position. ....

Probably a dumb question, but do you really mean the switch/control lever, or is it actually the throttle trigger you refer to?

 

[Stihl #1]

If it dies as soon as you open the choke then it is starving for fuel:
no impulse signal
massive air leak
plugged fuel filter
bad fuel line in tank or between tank and carb
fuel pump diaphragm
inlet screen in fuel pump side of carb
plugged main nozzle check valve or circuit
H screw in too far
...

I am not trying to be a smart a** but when troubleshooting an engine all possible faults have to be checked so you know what faults are present as well as what faults are not. It is a process of elimination so you don't miss something and so you find all faults present, and often there is more than one. A scored piston means it was probably run with a lean fault, and the reason must be found before just slapping in a new piston.
STIHL has a worksheet that walks the dealer technician through an evaluation to do this, it is part of the Service Advantage training. See if you can find a local dealer that will help you out on doing it.

 

[DOJO]

Reading the forum get me confused about the pressure test as it been said that gasket can pass the pressure test but fail the vacuum. So what is the point of the pressure test if it might work or might not.

Erick; bought the carb kit and changed it. Checked the carb and it looks ok, but i'm not sure.

secureland; how do i check that?
Yes, i read them and there are some post that are like mine but there was no follow up so I do not know if it helped or not. Just wish they would follow up 8-/

SawTroll; I will try to explain, sorry, i'm new to the saws. Got a switch on start(choke) then then pull the rope. Once I get it started, i press the trigger and when I press the trigger the switch changes the position from "start" to ON. Switch goes it automatically every time I press the trigger.



Stihl #1;

no impulse signal -- how do i check that?

massive air leak -- will try to test it

plugged fuel filter -- new fuel filter with hose, and the other fuel hose seems to be ok.

bad fuel line in tank or between tank and carb --- new fuel line hose, and the other fuel hose seems to be ok.

fuel pump diaphragm -- is that the one in the carb?

inlet screen in fuel pump side of carb -- new carb kit, should have fix that?

plugged main nozzle check valve or circuit -- not sure what you mean

H screw in too far -- is all the way in, with one turn out. Same with L

 

[mattinky]

Anytime a 2 cycle engine has a scored/siezed cylinder you must figure out why it happened. Just putting a new piston in it and expecting it to run correctly is not the answer, something caused it to sieze and you'll burn up your new piston in short order if you don't find out what happened in the first palce.

I've seen it a thousand times on old dirt bikes, someone will find an old bike thats been sitting in a barn for 20 years, put a new piston in it, take it out and sieze it up in about 5 minutes because the crank seals are shot and then bring it to me wondering what happened.

 

[secureland]

The other guys that posted know more about saws.

What I suggested is checked by taking off the plastic air filter cover, and looking down at the shiny silver piece that touches the black choke/off control. Put the black piece in the "run" postition, and see if the metal portion of the wire that comes off of the back of the black piece is touching the shiny metal contact spring. This grounds it out, just a possibility, but an easy thing to check.

Bill

 

[Mr.]

1. Start it with the switch to ON with a prime.

2. Report back.

Fred

 

[rmh3481]

Do you have a compression tester that you can give us a reading off of?

Are you saying you can get the engine to start and idle but the engine dies as soon as you hit the throttle trigger?

Thanks,
Bob

 

[Lakeside53]

Reading the forum get me confused about the pressure test as it been said that gasket can pass the pressure test but fail the vacuum. So what is the point of the pressure test if it might work or might not.

Gaskets fail symmetrically.. Seals MAY pass pressure but fail on vacuum. It's a lot easier to find a leak with pressure than vac...


Use SEARCH. There are many great posts on pressure and vac testing.

 

[DOJO]

Finally got the vacuum pump yesterday, waited 2-3 weeks to get it.

Just now was able to do a vacuum test. Pressure was dropping very fast, and it doesn't drop constant. At some point it stops for a second or two then start to lose pressure again. Used some oil around the crankcase gasket but wasn't able to find anything. So I guess it's the flywheel side gasket, does nay one got the part number for it?

 

[Dan Forsh]

9640 003 1190 flywheel side

9640 003 1600 clutch side

these are the oil seals, not gaskets. If you're going in I say change both.

 

[Bowtie]

Just a warning, the flywheel oil seal, (the small one) is a major PITA to get in correctly without popping the spring off the back side of it. If your dealer is worth a crap you might see if he will put at least this seal in for you for a decent price if you have the saw all ready for it. I ended up buying 3 seals before I got it put in right on mine. Still cheaper than Stihl's ridiculous price for their tools.

 

[DOJO]

Dan Forsh, thank you, i will order parts tomorrow. And will change both sides like you said.

Bowtie, thank you for that. Will definitely ask the dealer to change it then.