Troubleshooting Stihl 026 Won’t Run

[Matt Martin]

Hey guys, unfortunately I did not grow up in a mechanically inclined family so everything I’ve learned has been self-taught or researched online. My greatest accomplishment was rebuilding my push mower’s carb and getting it to run. I know, pretty lame.

My father-in-law paid $25 for an 026 that wouldn’t start and gave it to me. I’d like to try my hand at getting this thing to run. My biggest fear is taking things apart and not really understanding their function, but at some point I need to get over that. I thought this would be a great time to try.

What would be the process you experts would follow to see if you could get the saw started and running? What would you do first, second, third, etc? At what point, assuming your knowledge was limited like mine, would you give up? What parts should be replaced compared to being cleaned and put back on?

Thanks in advance for any and all help!!

 

[cuinrearview]

Remove the muffler cover and take a picture of the piston through the exhaust outlet and post it here.

 

[grizz55chev]

Pull the muffler to check the condition of the piston, should be smooth, no vertical streaking. If all looks good, pull the spark plug and place it against the cylinder with the lead attached and give the starter a yank to see if you have spark. If the saw has both of these things in good working order, chances are, the problem is fuel related. The next thing to do would be to squirt some fuel mix into the cylinder through the spark plug hole and reinstall the plug, then try to start the saw. If she fires and dies, chances are you’ll be needing to rebuild the carb. Good luck, hope this helps.

 

[cuinrearview]

In the chainsaw forum at the top under stickies you'll find the beg for manuals thread. Go there and ask for a service manual and IPL. Those will help a lot.

 

[HarleyT]

here....

 

[cuinrearview]

Lol, or just "@" Triumph...

 

[Jasonrkba]

$25!!

 

[Matt Martin]

Here’s a pic of the muffler cover removed and looking at the cylinder... I THINK!!

;-)

 

[HarleyT]

Ow!!

 

[grizz55chev]

Here’s a pic of the muffler cover removed and looking at the cylinder... I THINK!!

;-)

Looks like you’ll at least need new rings, I’ve seen a lot worse.

 

[HarleyT]

At least a new piston and 2 rings.

 

[Matt Martin]

For my knowledge, what’s the negative of running the saw with piston and rings in their current state?

Is it worth repairing this saw? Or am I going to spend the equivalent of a new saw on parts?

 

[grizz55chev]

For my knowledge, what’s the negative of running the saw with piston and rings in their current state?

Is it worth repairing this saw? Or am I going to spend the equivalent of a new saw on parts?

Chances are, the cylinder is saveable,not so much if you keep running it with those score marks . A good meteor piston with caber rings, pressure-vac test, you might be back in business for around $50.

 

[cuinrearview]

For my knowledge, what’s the negative of running the saw with piston and rings in their current state?

Is it worth repairing this saw? Or am I going to spend the equivalent of a new saw on parts?

It most likely wont make enough compression to run as is.

 

[rupedoggy]

 

[Matt Martin]

I took the air filter off and tested the plug... got spark. Sprayed a little 40:1 into the carb and boy is that chord hard to pull. A couple of times I got a “pop” coming out of the cylinder through the exhaust outlet.

 

[Ax-man]

I'll chime in here . That saw will run with that piston and rings . It may not run quite right or will be weak but it will run enough to see if you want to put money into a new piston and rings.

Did you put the muffler back on when you primed it to see if would fire ???? If you did remove the muffler and put it off to the side and then try to prime it to see if it starts. Don't put it back on till you get the saw running if you get that far. That saw has been run really rich, too much oil and not enough gas, judging by all the carbon build up around the exhaust port. Your muffler probably looks the same way on the inside and probably has the spark arrestor screen all clogged up.

Does the plug look like that exhaust port ??? All black and cruddy looking . If it does clean the plug up and try priming it . If you have gotten it to pop already the saw should start and run for a brief moment and then die. You probably have enough vacuum and compression to get the saw to start on prime. If you get this far about all that is left is to see if the carb works. Dump some fuel in the tank and see if it will start and run.

If you get the saw to run even briefly the rest will fall into place.

 

[grizz55chev]

I'll chime in here . That saw will run with that piston and rings . It may not run quite right or will be weak but it will run enough to see if you want to put money into a new piston and rings.

Did you put the muffler back on when you primed it to see if would fire ???? If you did remove the muffler and put it off to the side and then try to prime it to see if it starts. Don't put it back on till you get the saw running if you get that far. That saw has been run really rich, too much oil and not enough gas, judging by all the carbon build up around the exhaust port. Your muffler probably looks the same way on the inside and probably has the spark arrestor screen all clogged up.

Does the plug look like that exhaust port ??? All black and cruddy looking . If it does clean the plug up and try priming it . If you have gotten it to pop already the saw should start and run for a brief moment and then die. You probably have enough vacuum and compression to get the saw to start on prime. If you get this far about all that is left is to see if the carb works. Dump some fuel in the tank and see if it will start and run.

If you get the saw to run even briefly the rest will fall into place.

You’re right on with the too much oil symptoms, lean run condition streaks all the way across the exhaust port, the streaks your piston show is more likely carbon damage. That cylinder is likely salvageable.

 

[Matt Martin]

I stopped trying to crank it because when i pulled on the chord it was pretty tough. This is probably a time for me to learn something...

When I had the plug out and resting on the cylinder to test for spark, the chord pulled like any good operating machine. When I put the plug back in it got hard to pull the chord. I could pull it, then would hang up, a little further, than hang, etc. What causes this?

Should I just keep yanking on the chord until I get it to run for a few seconds? I shouldn’t have to spray any more fuel mix until it actually cranks and runs for a few seconds.

And yes, I left the muffler off. I also took the air filter out to get to the carb. It looks like it’s never been changed. The saw is horribly dirty with oil/dirt/sawdust/carbon debris everywhere.

 

[Ax-man]

The top of the piston probably has excess carbon build up and the rings might be sticking because of the same problem. Take a look at the top of the piston with the piston down and the exhaust port all the way exposed . If it looks like that exhaust port on the outside that is most likely why it is hard to pull over with the plug in the cylinder.

Give the saw a good bath with top cover off and the starter removed with an air compressor and some kind of soap based detergent degreaser like purple cleaner, simple green. Dawn dish soap will work also. Make sure the piston is up covering the entire exhaust port, spark plug installed, and the carb inlet is covered . You don't want to blow any more dirt and kunk into the inside of the engine. After the soap bath give the saw a good air drying with the air compressor.

If you take the starter off check to see if the rope pulls free and pulls back freely. If that works ok then your hard pulling over problem is in the engine itself. Take the plug back out and see if the engine rotates freely by turning the flywheel that is under the starter cover. You will be able to tell much better if your engine is hanging up in certain places by moving the flywheel back and forth . Look at the piston while doing this also to see if it is at the top or bottom of the stroke and take a look at the inside of the cylinder for vertical scoring marks.

Carefully scrap some of that carbon build up out of that exhaust port with a small screw driver with the piston up and covering the entire exhaust port. Don't let any of that stuff get near the piston or inside the engine and DO NOT scratch the piston itself with a screw driver. After you do that move the piston down and squirt two cycle mix onto the top the piston ,don't be afraid to use too much . Try moving the engine up and down now . Also try this with the plug installed . Basically what your doing is trying to get the engine good and loose so it moves freely.

If this doesn't work then more drastic measures are called for.