Stihl 026 Compression

[blsnelling]

How can the piston have some scratches, but not the wall?

The lining in the cylinder is much harder than the aluminum piston.

There was alot of carbon build up on the exhaust port. Do you think that the build up could hit the piston and scratch it without causing damage to the cyl. wall?

Yes. I've seen it before to a lesser extent.

 

[Lakeside53]

Thanks, Andy.

The rings look fine, and like I said, no cyl. wall scratches. I usually don't fix something that is not broke. I will help him keep and eye on it, though.

I do want to clean all of that carbon build up on the exhaust port. I have seen some threads using oven cleaner, brake cleaner, gas-mix. What do you think is best, and where should the piston be in the cylinder at the time of cleaning?

The cylinder should be OFF! You MIGHT get away with it by setting the piston to BDC, then keeping air blowing though the plug hole while you scrape..

Scraper (I often use a screwdriver) and a rotor wore brush. Liquid leaners are worthless on the hard dry carbon. EDTA only removes the calcium deposits. Oven cleaner will remove your pistion if you're not careful.

 

[blsnelling]

I would encourage you to go ahead and tear into that thing. You can get a piston here for $30. LINK. While you're in there you can properly clean the exhaust port and inspect/hone the cylinder.

 

[Lakeside53]

ah... Brad.... he has an 026? Wait.. is he talking about his buddies 029? I'm so confused...

You can get an OEM 026 piston for less then Baileys from Bcorradi - an AS member...


Oh.. lot more work to take an 029 down than an 026...

 

[blsnelling]

No Andy. I'm the one confused I guess I was just looking at his username.

 

[stihl025]

LOL!!! Chaos and confusion!!! My work is done here.

Without tearing into the saw completely, I was just trying to clean her up a bit. Not sure if I want to take the chance of ruining something prematurely. The saw is 13 years old (as is my 025) and still runs strong. Just needed a muffler mod, new carb kit and some hoses (oh, ya, and a good cleaning). We'll see how long this saw last with the original P&C. I've got him on the right track with better gas and Ultra oil, and teaching him to do a better job of keeping the air cleaner "clean". Maintenance is everything, especially when it is preventive. That dang 029, runs like a champ.

 

[Stihl051master]

I must have taken about 30 pictures, inside, outside, flash, no flash, I just can't seem to get a pic that shows up well on here - the picture makes things look much worse than what it looks like in real life. I can barely fit my pinky finger in there, but you can't feel any gouging on the piston. Soooo, I rebuilt the carb and put it back together. The saw starts and runs well, I was testing it out today. Thanks for all the input from all who replied. One additional question - It has a Walbro carb (WT) 194A I believe that has adjustable jets. I have heard a lot of people say theirs have fixed jets??

 

[bcorradi]

I must have taken about 30 pictures, inside, outside, flash, no flash, I just can't seem to get a pic that shows up well on here - the picture makes things look much worse than what it looks like in real life. I can barely fit my pinky finger in there, but you can't feel any gouging on the piston. Soooo, I rebuilt the carb and put it back together. The saw starts and runs well, I was testing it out today. Thanks for all the input from all who replied. One additional question - It has a Walbro carb (WT) 194A I believe that has adjustable jets. I have heard a lot of people say theirs have fixed jets??

Good to hear its running good. There are some out there with fixed jets, but the 194 carb is the most desirable carb they put on them.