026 Can This Be Saved Or Junked

[bigbadbob]

Got a near dead 026. 140lbs compressions.

Opened up the muffler saw some scoring so I pulled it apart.
Here is what I found. This is the exhaust side, the intake side was fine.
What do you all think I should do???
What caused this??
Whats the cylinder made of??
TIA

 

[sawfix]

026 save or junk

hey. take a hone to the cylinder looks like itll clean up get a new piston and rings and throw her back together.. check the crank bearings and seals while your in there.... or send it to me!

 

[davefr]

I'd pay the $89:

http://www.baileysonline.com/itemdetail.asp?item=CK+026&catID=258

 

[adkranger]

If the rest of the saw is good, get a new piston/rings, clean up the cylinder and get back to cuttin'.

 

[bigbadbob]

Well I had better see if the cylinder will hone up first, and go from there.
I can just hook my nails in it.
Any idea what caused the mess???
Bob

 

[Scooterbum]

Save the OEM cyl. if possible........

I'd do the Q-Tip with muriatic acid on the cylinder and try and save it if it's an original OEM.Just use the search there are plenty of how-to's on cleaning up a cylinder.
Just be careful and don't get any on any of the aluminum surfaces. Ask me how I know.

Get a new piston and rings.Also make sure you use new pin clips.

Post pictures of your progress and I'm sure there will plenty of guidance. Good Luck !! Steve

 

[bigbadbob]

Scooterbum thanks.
I will try that first.
The rest of the saw is quite clean.
Bob

 

[sawfix]

026 saved or junk

hey ill take a guess thats carbon scoring. maybe too rich,bad gas. cheap 2 stroke oil? ive seen this in johnson, evinrude ficht outboards and its carbon fouling. got two of those junkers. anybody else have any ideas?

 

[bigbadbob]

I dont know the saw history but it seem to be running rich and a rich mix as it smokes bad. Piston had a fair amount of carbon on it. The muffler has a fair amount of oil and carbon. What was interesting was one of the inner muffler bolts was off and the gasket was blocking the exhaust port some. Who knows what effect that has, or how long it was like that!!!
Bob

 

[sawfix]

yeah. it looks to me like carbon buildup was breaking or sloughing off and leaving thru the exaust port. carbon is extremely hard. i think the problem will vanish when you put her back together and tune the carb.

 

[Lakeside53]

It's just a lean seize... either from no oil in gas, or whatever. It's been run after it had a problem, and that's why you see carbon.

 

[bigbadbob]

Thanks Lakeside.
I will make up a jig and vacuum test it to be sure of the seals etc.
How many inches of vacuum do saws get tested with??
TIA
Bob

 

[Lakeside53]

about 0.4 BAR.

If you need a P&C, email me.. don't buy Chinese...

 

[timberwolf]

+1 lake

If it was carbon, I would think the problem would not be localized to the exhaust skirt only , but would be all around the piston crown, also you would see much more sign of carbon about the rings.

Hard to say if the jug can be saved, if it is though the plating anywhere the jug is pretty much junk. Piston is junk for sure. I am not a big fan of honing plated jugs, the plating is very thin and ball hones have two problems. They can't get to the top of the bore and also they hit the edges of the ports hard and can cut through the plating in that area very fast.

I would say if the jug cleaned up nicely just a piston and set of rings, otherwise it neds a P&C.

 

[Scooterbum]

Yeah I'm not a big fan of ball hones either. I usually use a wheel cylnder hone with a piece of red scotchbrite wrapped around it.Just slow and easy.I can get the top of the combustion chamber to boot and I don't have to worry about snagging a port.

 

[Lakeside53]

The secret to a ball hone is using the right size - most guys try to ram a way too big hone in... I use 320C and have never cut though nikasil plating, even around the ports. Chrome could be a problem.

 

[andrethegiant70]

I suspect that cylinder will clean up just fine.... looks like transfer to me. Piston, rings, clips, and I think you'll find you've got a happenin' saw again. Keep that thing tuned, though, and check out all your rubber....it got that way for a reason.

 

[bigbadbob]

Did the acid cleanup. Little sanding, not to bad, still grooves, but above the ports are two deep grooves that are deeper than the nicasil coating, so I will replace the P/C. Looks like something very hard must have gone up and down, few small dent in the piston to.

Thanks for all the help. Will do a pressure/vacuum test a bit later, will post if it fails.opcorn:
Bob

 

[NWnewguy]

Great thread

It seems like there are less threads like this to read lately. I really like the ones that I get to learn something on. Sure beats all the Husky -vs- Stihl threads. That muratic acid is really cool stuff. You also use it to etch concrete if I am not mistaken.

 

[bigbadbob]

Here is an update. I have never done this before, was interesting to say the least.
I made a vacuum/pressure tester. Real work of art, looked like ER.
Anyhow the saw would not hold more than 3 inches of vacuum, no obvious leaks. So I did the pressure test using some pressure testing fluid, no obvious leaks, covered the whole saw with fluid. But searching I had read some posts of Lakesides on leaky flywheel side seals. And some others on saws that had a hard time staying tuned as this one did. Well I dont have a Stihl puller so cant see in there.
What to do??? So I sealed up all the orifices and dunked the saw in a five gallon bucket of water, it was under pressure at this time. and low and behold I get bubbles from the flywheel side seal. So will have to get that done. Should I do both seals?? Bearings seem fine.