# Metal piston stop or rope?



## glennschumann (Sep 7, 2008)

I've always used rope to hold the piston when removing clutches, but I was wondering if the collective wisdom here has a preference... a length of clothesline or a metal piston stop, or ???


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## Jonny Quest (Sep 7, 2008)

I've used the rope method before, but I now use the piston stop. I got mine from Bailey's for fairly cheap. I have heard accounts of pieces of rope being sheared off and causing problems in the cylinder / crank case.

"...always use the right tool for the right job..." still applies here.

JQ


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## Lakeside53 (Sep 7, 2008)

The screw-in metal piston stop should only be used (with care) if your sparkplug hole is perpendicular to your piston (old saws).. Sometimes, often because they were put on too loose, clutches need way more leverage, ft-ibs, brutality etc that a piston can hold on a point contact, and it will break though the top... 

Use 3/8 poly rope... just make sure the piston is traveling in the right direction (up) and is above the exhaust port. And, take it out and re-insert before putting the clutch back on (direction revereses, rope falls in).


I do maybe 10-20 a week... and use rope almost every time now. I don't use the Stihl "spoon" tool now and then but it's way too fiddly to get in exactly the right spot (squish zone) on some saws.


BTW... according to Stihl, the "right tool" on all saws exact the old types (08, 041, 075 etc) is the "spoon", and definitely not the screw-in piston stop.


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## superfire (Sep 7, 2008)

*piston stop*

me i read on another posting about using an impacted gun. i take the spark plug and muffler off for safety. then i use and impact gun. impact guns are faster and less likely to make a plethera of cusing from spilling forth


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## Urbicide (Sep 7, 2008)

I normally use an impact wrench so I don't need a stop. A synthetic plastic one comes with Bailey's piston ring compressor set. One also came in the tool set with my MS-200T.


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## Lakeside53 (Sep 7, 2008)

careful... Impact wrenches on some saws can shear the flywheel key or break the crank. The 200T is one... I seen several over the years, and watched a guy do exactly that 30 seconds after I asked him not to...

Most of the "cast" key slot type on weeaters and small blowers will shear off - done a few of those myself..


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## Crofter (Sep 7, 2008)

+1 on getting the piston on the upstroke for the direction you will wrench and top above all the ports! Stuff in *as much rope as you can*; it will do a better job of equalizing pressure and not be exerting force on maybe just one side of the squish zone. Also the closer to top dead centre toggle over the greater the stresses on the piston and bearings. The further down the bore the better the crank angle advantage is in your favor.


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## Philbert (Sep 7, 2008)

Impact gun is something I am not likely to have in the field, like when changing a Husky sprocket. I've used the screw-in metal piston stop and the Stihl plastic thing (is this the 'spoon'?). Expect to use the rope sometime.

Philbert


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## Edge & Engine (Sep 7, 2008)

I use both (rope or metal piston stop). 75% of the time I use the metal piston stop. I have never damaged anything by using it...however, like anything else, you need to use caution and moderation in the force that you apply.


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## NDtreehugger (Sep 7, 2008)

*I use them both*

There simple to make.

I use an old spark plug drill and tap insert a bolt peen it down to keep them together and allow for removal grind round and smooth


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## woodheater (Sep 7, 2008)

The "safest" way to lock up any engine for clutch or flywheel removal and installation is to hydraulically lock the engine with some light oil. Rotate the engine in the direction that you need it locked in until the piston is almost TDC and the fill the cylinder with oil through the spark plug hole. Re-install the plug and you can SAFELY put whatever torque is necessary to remove or install either side without worries. I am not saying this is the cleanest method but I promise you will never damage a piston like this because the load is evenly distributed over the entire surface of the piston deck. I have done this for years on everything from RC car engines to snowmobile engines and it works like a charm every time without the "pucker feeling".


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## shawn022 (Sep 7, 2008)

*definatley rope*

First post but have been reading for awhile. 
I used a metal stop one time and it left a nice ding in the top of the piston ( luckily it was scored anyway). The stop wasn't rounded over on the end ,it was flat and had a edge that dug into the piston. Now I only use rope and haven't had any problems.


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## Bill G (Sep 8, 2008)

woodheater said:


> The "safest" way to lock up any engine for clutch or flywheel removal and installation is to hydraulically lock the engine with some light oil. Rotate the engine in the direction that you need it locked in until the piston is almost TDC and the fill the cylinder with oil through the spark plug hole. Re-install the plug and you can SAFELY put whatever torque is necessary to remove or install either side without worries. I am not saying this is the cleanest method but I promise you will never damage a piston like this because the load is evenly distributed over the entire surface of the piston deck. I have done this for years on everything from RC car engines to snowmobile engines and it works like a charm every time without the "pucker feeling".



That sounds interesting. I would think you would need to be extremely careful not to allow the piston to drop back down and lose oil into the ports. Also I assume you are using a heavy oil so getting it back out needs flushing.

Bill


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## woodheater (Sep 8, 2008)

Bill G said:


> That sounds interesting. I would think you would need to be extremely careful not to allow the piston to drop back down and lose oil into the ports. Also I assume you are using a heavy oil so getting it back out needs flushing.
> 
> Bill



I like to use a light oil like Marvels Mystery Oil or air tool oil. If it gets down in the engine through the ports I just hold the saw upside down with the plug out and give a few pulls. Again if you get the piston very close to TDC it doesn't take very much oil to lock it up.


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## Mike Van (Sep 8, 2008)

Use what you feel most comfortable with - I don't see how the rope method can do any damage, the metal stop like Lakeside said can do damage if the hole is on an angle. An impact wrench in the wrong hands...... crankshafts are $$$$$$$$. I've seen a few studs snapped off axle hubs, lotta torque there.


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## Mike PA (Sep 8, 2008)

Both work, with caveats.

Piston stop can poke hole in piston, as the top of the piston is weak.

Rope works well, but care must be taken to keep it out of ports/ exhaust. Insert rope when piston is near top to avoid this happening.

Another option is a squish wrench (not sure if this is the proper name). It is a curved rod that is inserted into plug hole and placed near the side of the piston (piston strongest at sides).


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## glennschumann (Sep 12, 2008)

Recently, this thread came up... see for pictures of what a metal piston stop did to a piston. I'm going rope from now on.

http://www.arboristsite.com/showthread.php?t=75896

Oh, but this is what rope did...

http://www.arboristsite.com/showthread.php?t=75926

Lets just be careful out there...


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## blsnelling (Sep 12, 2008)

glennschumann said:


> Recently, this thread came up... see for pictures of what a metal piston stop did to a piston. I'm going rope from now on.
> 
> http://www.arboristsite.com/showthread.php?t=75896
> 
> ...



That was a plastic piston stop. Metal would probably even be worse. I'll never use anything but rope from now on.


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## lesorubcheek (Sep 12, 2008)

glennschumann said:


> Oh, but this is what rope did...
> 
> http://www.arboristsite.com/showthread.php?t=75926
> 
> Lets just be careful out there...



That was on one of those cheap little stihl saws though  . Rope is the way to go.

Dan


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## oldsaw (Sep 12, 2008)

never used anything but rope.

Mark


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## blsnelling (Sep 12, 2008)

lesorubcheek said:


> That was on one of those cheap little stihl saws though  . Rope is the way to go.
> 
> Dan



Cheap until you haveto buy a piston for it


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## lesorubcheek (Sep 12, 2008)

blsnelling said:


> Cheap until you haveto buy a piston for it



I can only imagine. Cheap quality/performance is not equal to cheap cost.

Dan


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## blsnelling (Sep 12, 2008)

I disagree on the performance aspect. They have good speed and power for what they're designed to cut.


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## lesorubcheek (Sep 12, 2008)

Previous statement was a generality focussed at the economy over a wide spectrum and in no way insinuating that a STIHL of any type was low quality or performance!!!! Just happy I don't own a wussy saw that'll bend a rod trying to get the clutch off  .

Dan


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## blsnelling (Sep 12, 2008)

Or have a piston crown that's only 0.075" thick!


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## sawdoctor (Sep 14, 2008)

99.9% of the time I'll use an impact wrench (dont get over excited when refitting and tightening the clutch, just make sure the sidecover is on when running the saw up and it will tighten itself anyway)

Other 0.1% I use 4mm starter rope doubled to prevent loose ends getting trapped in ports.

In the almost 16 years i've been working on saws (daily) I have never damaged a piston/rod or sheared a flywheel key. 

Common sense is required though!


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## heimannm (Sep 14, 2008)

*Where can I buy...?*

Where I can buy the common sense? 

Do any of the sponsors offer a package deal with rope, piston stop, and impact wrench? 

I like the hydraulic lock idea, but sounds like it takes too much effort and probably won't work with my leaky old McCullochs anyway. Glad the old yellow saws all have a way to lock the flywheel using a 3/16" rod through the cover.

Mark


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## icelation8 (Sep 14, 2008)

Lakeside53 said:


> I do maybe 10-20 a week... and use rope almost every time now. I don't use the Stihl "spoon" tool now and then but it's way too fiddly to get in exactly the right spot (squish zone) on some saws.
> 
> 
> BTW... according to Stihl, the "right tool" on all saws exact the old types (08, 041, 075 etc) is the "spoon", and definitely not the screw-in piston stop.



Have you used the new design of the spoon?? part # 0000 893 5904 it is listed as a 192 c locking strip but it works 10 times better than the original plastic "spoon" This one is thinner and has aluminum or some sort of metal on the ends of it.


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## madrone (Sep 14, 2008)

I had one bad experience with rope and it was because I didn't notice a little fraying on the end I pushed in the jug. The damn thing got caught on the piston and jammed up then broke off when I tried to pull it out. Had to pull the jug to clear it up.
Admitted, this was all my fault but don't let it hapen to you! Make sure the end doesn't have any hangers!!!!:monkey:


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## aokpops (Sep 14, 2008)

impact


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## adamc (Sep 14, 2008)

heimannm said:


> Where I can buy the common sense?
> 
> I like the hydraulic lock idea, but sounds like it takes too much effort and probably won't work with my leaky old McCullochs anyway.



For leaky saws or if light oil isn't handy, I hear that sand works well too. Distributes the force over the full area of the top of the piston and doesn't seep past the rings.  

Adam


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## lumberinspector (Sep 15, 2008)

I've been using the metal piston stop but I went out and purchased some rope after seeing this thread. 

I don't think I could use rope and bend up the internals like that done in another post but I know now that I could do what the piston stop did.


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## RES (Sep 15, 2008)

Ends of rope can easily be stopped from fraying by using a torch or charcoal grill lighter to singe the ends. It works quite well.


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## timberwolf (Sep 15, 2008)

> I hear that sand works well too


:jawdrop: 

Sand is one of a two strokes worst nightmares, I would never considder putting sand in an engine. If you were going to put something powdered in, maybe corn meal or something less abrasive or likely to damage surfaces or bearings. If oil is too thin squirt a little grease in with a grease gun, put a junk spark plug in an it should be good.

Still I think an air impact is the easiest on the engine (done with care). It works larrgly against the inertia of the crank and flywheel and because of that is going to put less load on the crank, rod and bearings. Also there is no trans-axial force on the end of the crank like what you get with a wrench or socket. Pushing or pulling on a wrench or ratchet twists the nut, but also it pushes or pulls the end of the crank sideways.


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## adamc (Sep 15, 2008)

timberwolf said:


> :jawdrop:
> 
> Sand is one of a two strokes worst nightmares, I would never considder putting sand in an engine. If you were going to put something powdered in, maybe corn meal or something less abrasive or likely to damage surfaces or bearings. If oil is too thin squirt a little grease in with a grease gun, put a junk spark plug in an it should be good.



Umm... sorry. Should have been more clear that my sand suggestion was a joke. A little while after posting it, I actually considered editing, but I figured no one would take it seriously.

So, for the sake of clarity NEVER put sand into an engine!! Unless of course it belongs to your wife's boyfriend.

Adam


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## Lloyd H (Nov 3, 2008)

*rope in cylinder*

A little off topic but rope wadded in the cylinder holds four stroke valves shut to change the springs quite nicely as well. Air works but rope works better, with air the prop will beat you up when the engine rolls over.


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## oldsaw (Nov 3, 2008)

Lloyd H said:


> A little off topic but rope wadded in the cylinder holds four stroke valves shut to change the springs quite nicely as well. Air works but rope works better, with air the prop will beat you up when the engine rolls over.



A few years ago I had to fix my FIL's riding mower. Memorial day weekend, the screws in the butterfly had come loose and the motor ingested them and the butterfly was resting on top of the intake valve. One screw in the cylinder the other in the muffler. Using what I had on hand, a beer can, some old screws out of a scrapped computer printer, some wire, epoxy, and threadlocker, I rebuilt the carb, tore off the top end (OHV Briggs) and put it back together again. I was a bit stumped on the valves until I started thinking two stroke and got some rope. Ran it for another couple of years before it drove a rod through the block. That thing had more hours on it than you could ever imagine. It was long past dead, it just didn't know it. Thank you Anheiser Busch.

Mark


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## Ptarmigan (Sep 3, 2009)

I'm just disassembling my first saw for a rebuild, and after slicing a couple of fingers open on my first attempt at removing the clutch, I read the manual, then I searched on here for other advise seeing how I can't get a piston stop at 9 o'clock in the mountains. Luckily I have the internet and all of you to help out. I thought about the rope, as we have plenty of that laying around. But the oil technique is familiar to me... used that on my van to remove the pilot bearing from the crankshaft. A few minutes later.... after running through which way the engines turning and the nuts turning to allow me to lock it off. The clutch is removed. It's draining right now as I learn how to remove the fly wheel. I'm planning on re ringing the piston so residual oil isn't really a concern right now. Thanks for the tip.

Sean


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## got2dv8 (Aug 20, 2010)

*Thanks for the thread!*

:yourock:Just stumbled upon this thread and it was extremely helpful for flywheel removal and installation on my Stihl HS81R & T. The rope worked awesome and saved me some headaches... except for the fact that I busted a fin off prior to finding this site. Now I know better.

Robert


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