026 Problems

[Adirondackstihl]

A buddy of mine brought me his 026 to work today to take a look at.
Tells me it runs O.K. cold, but once its hot it dogs out and dies.
He tells me he put a new plug & diaphragm kit in a few weeks ago.
I'm still at my desk and havent even looked at the saw yet.
Any ideas?

Few things come to mind..
1) Cylinder pulling air from somewhere it shouldnt be and leaning out.
2) Clogged muffler screen
3) Poor carb adjustments

PS....The saw has had a fresh top end not too long ago

Any insight is greatly appreciated.

 

[PA Plumber]

Here's a recent thread on an 026...http://www.arboristsite.com/chainsaw/182999.htm

Fuel tank vent, new fuel filter, Air filter clean, did he make sure the carb was clean before putting in the new parts?

 

[JustinM]

Tough to say with the limited amount of info you've given us (i know you only have a bit yourself).

Id probably start with the muffler (checking for carbon build-up) air filter and the tank vent. Hopefully one of those (minor fixes) would do it, but if not then it would be time to dig deeper.

 

[Adirondackstihl]

Thanks for the speedy replies.
I will start there I guess!!
Is the tank vent a common issue ?

 

[PogoInTheWoods]

PS....The saw has had a fresh top end not too long ago

I'd start by finding out why. Next I'd want to know if the reason it needed one was corrected. If it wasn't, it may need another one.

Poge

 

[jus2fat]

A buddy of mine brought me his 026 to work today to take a look at.
Tells me it runs O.K. cold, but once its hot it dogs out and dies.
Any ideas?

Check all the easy stuff first...of course...
But "dies when it gets hot"...sounds like a bad coil.
If it will start again and run when it cools off...then dies when hot again...coil..!!

J2F

 

[Adirondackstihl]

I'd start by finding out why. Next I'd want to know if the reason it needed one was corrected. If it wasn't, it may need another one.

Poge

Apparently the previous owner had it leaned way out and melted the piston.
I pulled the plug at lunch (which is the same plug it had when it melted) and it had a nice coating of aluminum on it. Gonna stick a new Bosch in it when I get home and run it for while.
I will keep you guys posted.
I think the temps from the previous meltdown did some damage to the coil now that you guys mentioned a possible coil issue. I will check spark with new/cold plug VS new/hot plug and see if there is any noticable difference.
Also gonna dump the fuel and put my mix in it. 93 mixed 50:1 with Stihl HP Ultra. Between a new plug and fuel that I know is mixed properly, this will give me a good starting point.

Also, any idea where the tank vent is located ? Still havent had a chance to look that deep into it yet.

 

[pioneerguy600]

The tank vent is just under the airfilter cover, on the left side just above the fuel tank filler cap.

 

[watsonr]

The tank vent is just under the airfilter cover, on the left side just above the fuel tank filler cap.

Jerry,
That was a very good reply to a simple question....calmly spoken to a man who reported that the piston was melted......rep inbound!

The piston is melted you replied and said that the aluminum was caked on the plug....do you really think it's going to run like that or run really good like that by changing the plug and new mix?

 

[atvguns]

Jerry,
That was a very good reply to a simple question....calmly spoken to a man who reported that the piston was melted......rep inbound!

The piston is melted you replied and said that the aluminum was caked on the plug....do you really think it's going to run like that or run really good like that by changing the plug and new mix?

Ready the whole thread it has a new top end with the same

 

[watsonr]

Ready the whole thread it has a new top end with the same

Yep, I read that it had a new top end some time ago, doesn't mean it is still good.

 

[watsonr]

I may have been a little premature in my response...but if the previous owner or the shop that fixed it put the same old plug with melted aluminum on it back in the saw to run, what else did he forget to do?

I would check the piston first thing and make sure it wasn't about to be toasted again, he may have used the same fuel as he did when it toasted the first time. Also check the muffler screen and fuel system because he said his buddy rebuilt the carb. Get the carb parts in the wrong order and that would do it and then coil.

He didn't mention that the saw wouldn't restart until it was cold, it just died out.

 

[PogoInTheWoods]

And while we're at it, do we want to suggest a vac/pressure test just to make sure that nasty little flywheel side crank seal isn't shot? Or the clutch side seal? Or the intake boot? Or the impulse line?

I'm guessing another piston meltdown in the process is what's happening due to not having the original problem properly addressed during the last top end replacement.

'Course it'll probably end up being the coil or the tank vent!:hmm3grin2orange:

Poge

 

[Adirondackstihl]

Well......I pulled the exhaust and found they had it already completely gutted and the exhaust side of the piston to be scored pretty bad. Think it may have had a bad crank seal and still does. Thats how I believe they cooked it the first time and why its cooked now! I dont have a compression tester, but it surely doesnt have enough IMO.

 

[rwbinbc]

Same thing that happened to Me, But mine was only a year old. The muffler is like that on the insde not much in there. They said I had bad mix in it, Thats BS. My other saw would have messed up to. I'm looking at rebuilding it soon. If You dont want to rebuild the saw part it out, We'll buy her.............

 

[Adirondackstihl]

Same thing that happened to Me, But mine was only a year old. The muffler is like that on the insde not much in there. They said I had bad mix in it, Thats BS. My other saw would have messed up to. I'm looking at rebuilding it soon. If You dont want to rebuild the saw part it out, We'll buy her.............

Might offer him $25-$50 for it as is.
It'll give me something to do this winter between hunting and ice fishing.
I'm always looking for a new saw to add to my collection

 

[PogoInTheWoods]

Might offer him $25-$50 for it as is.
It'll give me something to do this winter between hunting and ice fishing.
I'm always looking for a new saw to add to my collection

As you already know, it's a very easy saw to work on and parts are plentiful. If you can get it for 25~50 bux, jump all over it and get it running like it should. If you haven't run a healthy 026 before, you'll be pleasantly surprised!

Poge

 

[thomas72]

Fill out this little sheet and most of your problems will be solved.

https://www.ffa.org/documents/lps_stihl_stihlenginecheck.pdf

 

[Adirondackstihl]

As you already know, it's a very easy saw to work on and parts are plentiful. If you can get it for 25~50 bux, jump all over it and get it running like it should. If you haven't run a healthy 026 before, you'll be pleasantly surprised!

Poge

He at least wants the bar and chain back. I'll give him a sharpened chain back and see if $25 will take it