# Zero dollar ?fix? for scored piston/cylinder



## yawning_dog (Dec 15, 2007)

*Zero dollar “fix” for scored piston/cylinder*

Hi guys. I thought I would show you a little experiment I did on an 036. The saw was my father-in-law’s and he gave it to me saying it was hard to start etc. Well, he was right, but it did start after a while. It also seemed to idle okay and had good throttle response etc. But then I did one cut and the thing throttled down and stopped. Then there was no starting it again. Actually, I did get it started by holding it like a sword with my right hand, finger on the gas, and yanking on the starter like hell. I wouldn’t recommend this technique. But even then it wouldn’t idle at all. No carb adjustments would affect the operation.

So at that point I pulled the muffler and low and behold noticed that the piston was scored and the rings were stuck. Hmm, that could be a problem. I believe I measured the compression at about 110lbs cold. I decided to tear into it and see what could be done. For kicks, I decided to just clean up the cylinder and piston the best I could and put it all back together.

For the cylinder, I used muratic acid and a q-tip. I got it almost totally free of aluminum below the exhaust port as you can see from the pictures, but I probably didn’t do such a great job above the port. After that I used a ball hone on it. For the piston, I used a very fine grit wet sand paper to slowly remove enough material to get the rings out. This took some doing and it’s difficult because if you force them too much they’ll snap! I finally got them out and then I continued with the sand paper a bit in the affected area of the piston grooves etc. Finally, I cleaned everything off the best I could, put her back together, and fired her up.

I will say that it runs much better than it did. It’s not a 2 pull start though. It seems to have plenty of power, but the idle is pretty rough. Sometimes it will idle okay indefinitely, but sometimes it s..l..o..w..l..y dies. Low jet adjustments and the idle speed seems to affect it now, but I can’t say I’ve dialed in a setting that always works like a champ. That said, I haven’t really done more than a couple cuts with it either so I don’t know how it will act if it really gets warmed up and broken in. From the little use it’s seen, the saw shows about 130lbs of compression warm, which from what I’ve learned here is marginal at best.

Anyway, it seems like this is a hokey but reasonable technique to use if you don’t want to spend ANY money and you’ve got a few hours to mess around. Of course you’re not going to get a like-new saw out of it, but at least you’ll get some good garage time in! 


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## Four Paws (Dec 15, 2007)

yawning_dog said:


> From the little use it’s seen, the saw shows about 130lbs of compression warm, which from what I’ve learned here is marginal at best.



Depends on your elevation.


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## yawning_dog (Dec 15, 2007)

*cylinder picture: before and after*

Here's a picture of the jug before and after. Notice there's still some visible damage above the exhaust port in the after picture. And of course, I don't really know if I honed the sucker too long, not long enough, or just right. I used a Dewalt drill on the low setting for about 5 seconds or so with an almost brand new hone. For oil, I used some stuff I have laying around that is used when sharpening chisels etc. I've got a low budget operation going here!


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## blsnelling (Dec 15, 2007)

That cylinder cleaned up amazingly well! Your compression will be higher if you let the saw cool off. See what you get cold. Did you take a pic of the piston after cleaning it up? I wouldn't be surprised it she cuts good for you. Your compression isn't all that bad.


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## Cut4fun (Dec 15, 2007)

Thats how I found this site, having to repair my first saw on a bad ebay buy. Mine was almost the same way and the dealer wanted min $200 to fix. I spent $16 on ring and gasket and half of that was shipping. The saw is still cutting firewood to this day.

WTG taking matters into your own hands.


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## Haywire Haywood (Dec 15, 2007)

You should order a new ring for it. That's what I did with my 346 and got 145lbs out of it.

Ian


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## blsnelling (Dec 15, 2007)

That's interesting where the damage was on you P&C. It seems odd to me that it's way off to the side of the exhaust port.


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## yawning_dog (Dec 15, 2007)

Yes, I was actually surprised at how clean it turned out too. I've tried it before, and it always seems that there's some gouges that just don't come out. Of course that was the case here too, but it still looked fairly decent. 

The piston is another story. It's a wreck, but oh well. I did consider rings, but they really didn't look too bad. But then again maybe it's the microscopic stuff that matters. They did have some vertical scratches on them in the location of the piston scoring. 

I'm hopeful that I got enough out of the ring grooves and opened them up enough that the rings don't re-stick again. Of course I don't know why the saw scored in the first place and I didn't bother doing an vacuum or pressure check yet. So I guess one of these days when I find some wood to cut I'll try 'er out!


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## Jacob J. (Dec 15, 2007)

Did you clean the carbon build-up off the back side of each ring? 

You would get more compression and clean the cylinder up even further by taking ten minutes or so and running some emery cloth around on the cylinder walls with your fingers and some WD-40. That would get all of the discoloration off the wall and the rings would seat better giving you more compression after ten tankfuls of gas or so.


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## Lakeside53 (Dec 15, 2007)

130 is bad... sure it runs, but it will be a heck of a lot better at 150+.

Good work though.. do what Jacob suggests and try some new rings.

And.. if you don't know why it scored first time, unless it was a gas "mix" or adjustment issue, it may just happen again..


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## Scandy14 (Dec 15, 2007)

Good job.


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## yawning_dog (Dec 15, 2007)

*rings*

yup, maybe next time I send away for some other parts/chain etc. I'll put some rings on the order, assuming I can find them online. Regarding the emory cloth, I would think the honing would have taken care of that, right? Or are you saying to do the emory cloth after the honing? 

And yes, I did try to clean up the rings, front & back. But I really didn't look tooooo close at the back, so there's a chance I didn't get the carbon there. But I'll make sure to look at that the next time I try this again, if there's a next time. Thanks for the tip!

Regardless, it's a big hack, but at least it runs now! And as I said, I got some garage time!


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## Lakeside53 (Dec 15, 2007)

Maybe it's the light from the flash, but the honing looks rough. What size grit does your hone have?


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## yawning_dog (Dec 15, 2007)

It was a 47.5mm 180 grit silicon carbide ball hone by BRM. It's the only one I have and it happened to be "about" the size of the cylinder. So I took a shot at it.


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## RiverRat2 (Dec 16, 2007)

320 grit on the hone,,

when the new rings get here take one of the old rings and break it in half,,, use the corner of the broken edge to remove the carbon in the ring grooves go all the way around,,,, it would really run even better if you could find a new piston!!!!!!


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## yawning_dog (Dec 16, 2007)

180, 320, what's a little grit between friends... Oh well, I guess I now have an excuse to buy more stuff! I was actually overjoyed that the darn thing fit into the cylinder. Although I did have to sort of cram it in there! I used the same one for my MS170. kidding.


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## yawning_dog (Dec 16, 2007)

Oh RiverRat, and I'm sure you're right about the piston too. But as I said, I can't seem to find any trees to cut, or time to do it. So I just muck with saws when I can.


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## RiverRat2 (Dec 16, 2007)

yawning_dog said:


> Oh RiverRat, and I'm sure you're right about the piston too. But as I said, I can't seem to find any trees to cut, or time to do it. So I just muck with saws when I can.



You can probly find rings for about $12 or less,,, they alone would make a noticable difference,,, youll probably be fine with the 180 but 240 320 is better the rings will seat better and yield better compression,, especially with the ring grooves cleaned!!!!!!


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## yawning_dog (Dec 16, 2007)

Well, I may just take your advice on that. Do you happen to know how long it takes to seat the rings in a properly honed cylinder? I'm sure this has been discussed here thousands of times, so forgive me for being repetitive.


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## Lakeside53 (Dec 16, 2007)

5-10 tanks...


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## RiverRat2 (Dec 16, 2007)

*Here ya go!!!!*



yawning_dog said:


> Well, I may just take your advice on that. Do you happen to know how long it takes to seat the rings in a properly honed cylinder? I'm sure this has been discussed here thousands of times, so forgive me for being repetitive.



This guys an AS Site sponsor,,,

http://cgi.ebay.com/034-036-MS-360-...8877851QQihZ004QQcategoryZ79669QQcmdZViewItem

How much did I say??? 12.00,,, but I doubt for 12.00 their OEM

you can find the factory ones for eight bucks more,,,

call your local stihl dealer and see what he wants


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## blsnelling (Dec 16, 2007)

Your cylinder cleaned up very nicely. Why not just through a new piston and ring kit in it for $30? LINK The cylinder's the more expensive part. You wouldn't want to ruin it by trying to save $30.


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## RiverRat2 (Dec 16, 2007)

blsnelling said:


> Your cylinder cleaned up very nicely. Why not just through a new piston and ring kit in it for $30? LINK The cylinder's the more expensive part. You wouldn't want to ruin it by trying to save $30.



Please read post # 15!!!!!




RiverRat2 said:


> 320 grit on the hone,,
> 
> when the new rings get here take one of the old rings and break it in half,,, use the corner of the broken edge to remove the carbon in the ring grooves go all the way around,,,, *it would really run even better if you could find a new piston!!!!!!*


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## buck futter (Dec 17, 2007)

Carbon is your enemy, I hoped you cleaned up the carbon too. It also looks like you need to clean the muffler screen or open up the muffler.


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## yawning_dog (Dec 30, 2007)

Well, I ran two tanks through the 036 the other day. It had decent power and ran well when cutting. But it still struggled to idle. This wasn't a problem if I went cut to cut and kept blipping it. I adjusted the L a little here and there, but I couldn't seem to dial it in. 

Today, I couldn't get it started after about 25 pulls. So I check the compression and it was at a respectible 150lbs (cold). I tore down the carb again and tried to clean that up a bit. Put it back together and it started in about 7 pulls (seems normal for my Stihls). I need to adjust the carb tomorrow when the neighbors won't kill me, and maye get it hot enough to measure the compression hot. A work in progress...


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## RiverRat2 (Dec 30, 2007)

yawning_dog said:


> Well, I ran two tanks through the 036 the other day. It had decent power and ran well when cutting. But it still struggled to idle. This wasn't a problem if I went cut to cut and kept blipping it. I adjusted the L a little here and there, but I couldn't seem to dial it in.
> 
> Today, I couldn't get it started after about 25 pulls. So I check the compression and it was at a respectible 150lbs (cold). I tore down the carb again and tried to clean that up a bit. Put it back together and it started in about 7 pulls (seems normal for my Stihls). I need to adjust the carb tomorrow when the neighbors won't kill me, and maye get it hot enough to measure the compression hot. A work in progress...



Could be chasing a vacum leak?????? seals, manifold, impulse hose,,,, If you go all through the carb and it still does it??? dont run it much till you find the problem,,,,, and from whatyou describe it could be the idle circut is plugged with varnish or crud,,,try this,,,gently bottom out the L screw then remove it then take the carb cleaner spray with the red tube on and insert and while holding the throttle open so you can see the idle port inside the venturi squirt some cleaner and you should see a fine but solid stream then reinstall L screw and go back through the base line carb settings

Your getting 150 with just rings???? thats good for an old piston,,,,

Take both L & H in all the way then bring them both out 1 full turn

here is a good link for adjusting carbs,,,, 

http://web.archive.org/web/20051018212959/www.madsens1.com/sawtune.htm

rebaseline all the settings,,,, if it wont let you complete the settings properly than you have another problem


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## yawning_dog (Dec 31, 2007)

Yuppers, 150lbs cold. Surprised me too. I ran it just enough today to warm it up and then it tested at 135lbs. So still not stellar but it runs. It seems to run a little better since the carb cleaning. And your suggestion is just what I did. I do it both for the L and the H, which I assume is okay. I usually end up getting carb cleaner all over my hands, which I'm sure will lead to some form of cancer or leprosy later in life. But it's for a good cause, right?

If I get really motivated, I'll try the vacuum and pressure test. I bought one of those harbor freight specials that someone suggested in one of his threads. But I don't yet have all the couplings necessary to hook thinks up. Same goes for the blood pressure cuff I got from e-bay. So we'll see! 

Thanks for the suggestions. Happy New Year!


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## RiverRat2 (Dec 31, 2007)

if Im doing several I wear the blue heavy latex gloves,,, I dont like getting that Carb cleaner all over me any more than what happens by mistake much less just willingly getting it all over and not trying to minimize exposure?????

Yeah I suspect you have some wear on tha piston skirt and that why the hot readings drop so much,,,, but for how you get to use it,,,, it will last a little while,,,, A new OEM piston and fresh ringsW/Hone cyl. is hard to beat,,,,,


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## drmiller100 (Dec 31, 2007)

for the future, spend your time and energies working on the stuff abovethe exhaust port.

everything from below the top of the exhaust port can be considered a "performance enhancing boost port."

giventhat, i think you should have honed longer. 5 seconds is short, and you can see areas that didn't get honed.

the piston is along for the ride. the rings are important, as is the finish on the jug above the exhasut port.


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## yawning_dog (Jan 6, 2008)

Well, drmiller100 I think you're definitely on to something there. I did in fact spend more time cleaning below the exhaust than above. Mostly because it's hard to cram your hand in there to work on it... As far as honing longer, perhaps you're right there too, but others have noted that the hone I used had a grit too course. So it's probably a good thing I didn't hone longer in this case. 

I ran another two tanks through it today (fair amount of storm damage in Northern California). My neighbor's tree split in half and squashed our fence. Of course most of the tree ended up in my yard so I had a good excuse to do some sawin'. Anyway, the 036 worked very well. I had to do a couple 1/8th or less adjustments on the L to get it to idle consistently. Even then, it seems like it wants to stall, but it stays running. The saw is definitely usable now. It's a little bulky and tank like, but my feeble arms probably make it feel worse than it is. So I'm calling this one a wrap on the "zero dollar chainsaw fix"... Thanks again to everyone for all your tips on this subject. I'm sure I'll have the occasion again in the future to not spend money on a saw, so now I'm a bit more ej-e-cated!


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