scoring in 046....how bad is this

[PaulB84]

Owned this for a couple years, didn't know squat about saws when I got it. (Still don't honestly) The good news is I got it for a great deal, its pulling 135psi, runs great and has cut a lot of firewood for me. Starts on the 3rd pull, Idles well at all angles, was given a clean bill of health from a local stihl dealer soon after purchase (thanks a lot) I've only ever run 91 octane ethanol free w stihl HP oil at 50:1, god knows about the guy before me. I think I remember him saying he ran 40:1 but not positive about that. Air filter wasn't perfect but not filthy, replaced immediately after I bought the saw. It was also set a little lean when I got it, I retuned, didn't think much of it til I started getting into this on a more serious level. I assume it was too lean/cheap or stale gas/crap oil but again don't know anything for sure. Haven't done any leak tests. Anyway, what would you do? Did i catch it early enough to possibly save the piston or more importantly cylinder looks to me like the scoring is on both intake and exhaust side above and below the piston. Eff.....
Edit looks like pics were downgraded severely I can email originals to anyone interested. Can't really feel the grooves w a fingernail or pen cap but it def ain't right either.

 

[cgraham1]

Pull the jug and inspect. Don't try to run it anymore, it will just get worse.

 

[Definitive Dave]

plan on a piston and check the cylinder it will probably clean up, pistons are cheap, cylinders not so much
DDAve

 

[PaulB84]

Thanks guys. Should I be shopping OEM piston or aftermarket? Can someone point me towards one they would suggest?

 

[MillerModSaws]

Thanks guys. Should I be shopping OEM piston or aftermarket? Can someone point me towards one they would suggest?

Oem cylinder. Piston- a nice meteor would treat you nicely!

 

[sld961]

Call your dealer to check the price on an OEM piston. The prices have come down in most places. Some are actually cheaper than meteor. If it's close, go with OEM.

 

[blsnelling]

With the way OEM piston prices have dropped, you might as well go OEM. I have nothing against Meteor though. I just bought a 661 piston for $45!

 

[PaulB84]

Whoa! Just got off the phone w a stihl dealer and the piston kit is $41 plus shipping! That's some good news right there!

 

[cedarshark]

Thats pretty mild scoring but you will have some aluminum transfer to the cylinder. It will clean up w/ acid or jewelers grinder. $41 for an OEM piston is great! Don't forget to solve the problem that scored the piston though. From the looks of the inside of the muffler, that saw was certainly not running rich.

 

[crzybowhntr]

If your not familiar with removing transfer, this may be of some assistance. I used a piece of dowel rod with a slit cut length way and inserted progressively smoother sandpaper and emery cloth to clean a few (chucked into a drill)... I think the guy in the video is new at saws though so you may want to proceed with caution..

 

[LowVolt]

With the way OEM piston prices have dropped, you might as well go OEM. I have nothing against Meteor though. I just bought a 661 piston for $45!

OEM?

 

[cedarshark]

He will get better once he finishes that second saw.

 

[SS396driver]

OEM?

Stands for original equipment from manufacturer .

 

[PaulB84]

OK boys so brass tacks....I guess I gotta pull the cylinder and see what's what w the cylinder. Complete factory upper assembly is $260+ which makes this a paperweight since I stole it (or thought so!) for $350 w new bar and chain

Showed the pics to a couple guys who think they know saws and they all said the cylinder is toast. They may be right accidentally but I know enough to know they don't know about this website!

I now trust no one to work on my saws (present company excluded) and I'll be learning whatever I need to to make this the last time I'm this ignorant on the subject. I'm pretty POd but experience is a rough teacher; first comes the test, then comes the lesson.

 

[sld961]

Read through this thread before determining your cylinder is toast.

http://www.arboristsite.com/community/index.php?threads/248325/

 

[PaulB84]

Oh I absolutely have and will again (and again). I'm not saying it's toast, I'm saying I need to pull my first saw apart tonight and see what's what! Will be posting better pictures of the cylinder and piston and deferring to AS for more good advice. Thanks a bunch guys. Stay tuned......

 

[cedarshark]

OK boys so brass tacks....I guess I gotta pull the cylinder and see what's what w the cylinder. Complete factory upper assembly is $260+ which makes this a paperweight since I stole it (or thought so!) for $350 w new bar and chain

Showed the pics to a couple guys who think they know saws and they all said the cylinder is toast. They may be right accidentally but I know enough to know they don't know about this website!

I now trust no one to work on my saws (present company excluded) and I'll be learning whatever I need to to make this the last time I'm this ignorant on the subject. I'm pretty POd but experience is a rough teacher; first comes the test, then comes the lesson.

Absolutely no need to assume you need a new top end at this point. A jug w/ 135 psi compression can't be scored that badly. If you had the piston, rings and gasket, you would be running tonite. Remember....something caused it to score the piston. If you don't find out why...you will score it again.

 

[PaulB84]

Absolutely no need to assume you need a new top end at this point. A jug w/ 135 psi compression can't be scored that badly. If you had the piston, rings and gasket, you would be running tonite. Remember....something caused it to score the piston. If you don't find out why...you will score it again.

Understood. Going forward I think I can eliminate bad gas/oil, wrong mix, and bad tuning at the carb. So other than gaskets and impulse line, what else should I be replacing?

 

[cedarshark]

As you disassemble the saw, look for soft/torn fuel and impulse lines and check the intake boot for tears and rips. If you find no obvious leaks, you can re-use, but as you have the saw apart, I would replace the fuel/impulse lines just for peace of mind. Check your cylinder base gasket for a tear. You will need to do a vacumn/pressure test on the saw when you get it reassembled to check your work and ensure your crank seals are not leaking. I use a mityvac and pressure test the saw(7-9 psi) underwater as any leaks become very obvious by bubbles in the bathwater. This will require you blank off the intake and exhaust. Many threads here about the procedure. First things first. Get the jug off and post pics. Search the forum for threads on cleaning the jug with muratic acid if you dont have a jewelers grinder. IMHO, a dremel tool does not have the power needed. There is a wealth of experience here, dont be afraid to ask questions. We all had to do our first one !

 

[LowVolt]

Stands for original equipment from manufacturer .

Yes I am aware.

$45 for OEM?