Metal Piston Stop

[Caz]

Anyone use a metal piston stop and will it dent or scar the piston head ?

 

[Metals406]

Anyone use a metal piston stop and will it dent or scar the piston head ?

Most guys feed some rope through the plug hole to use as a stop... It's softer than a piston stop, and covers more surface area... So the piston isn't pushing on just a little area.

I've seen a couple pictures of guys putting holes in pistons' with piston stops.

 

[Caz]

I've heard the rope can sometimes get pinched between the piston and the cylinder wall, leaving bits of rope inside. Can this cause a problem ?

 

[Mike Van]

I don't think you can go wrong with 1/4" rope. Any small bit of it would burn right up if left behind. You can always pull the muffler, feed it in there too.

 

[pioneerguy600]

Yes the metal piston stops will leave a mark in the top of the piston. If you remove the muffler you might as well insert a wooden block or plastic block that will fit in the exhaust port over the top of the muffler, no metal in there please.
I personally use a battery impact driver to loosen flywheel and clutch nuts/ carriers and just hold the opposite side from the one I an removing with my hand. Some say that the crank end can be broken doing this but to convince me that this happens I would have to have the metal checked for fatigue or stress cracks. IMO
Pioneerguy600

 

[Edge & Engine]

Metal piston stops were OK for the old horizontal saws, because the spark plugs are in line with the piston. Most modern saws have an angled plug, I have occasionally used a metal piston stop in a pinch and have never done any damage, however it's better to use plastic stops through the spark plug hole, plastic stops through the exhaust port, or rope.

 

[KenManiac]

I used a length of fuel line the one and only time I took the clutch off my Husky 350. Braid-covered VW style stuff, tight fit in the spark plug hole. Didn't feel like going inside the house for rope.

Worked fine!

 

[woodyman]

I never used one,every one says stuff a rope in through the spark plug hole because of damage to piston may result from using a metal piston stop.I took off the clutch on my 026 the way I did all my older Husqvarnas,I put the scrench on the nut and brought it up to compression and wacked it with the handle of a hammer.

 

[pinemartin]

I never used one,every one says stuff a rope in through the spark plug hole because of damage to piston may result from using a metal piston stop.I took off the clutch on my 026 the way I did all my older Husqvarnas,I put the scrench on the nut and brought it up to compression and wacked it with the handle of a hammer.

this is my preferred method

 

[superfire]

another idea

remove muffler and spark plug. then use a tooth brush handle in the exhaust side of the engine
:greenchainsaw:

 

[blsnelling]

I will never again use a piston stop that screws into the spark plug hole. I know it's a tiny little piston, but I put a plastic screw in stop right through the crown of the piston on a MS180 simply trying to loosen the flywheel nut. Either use a piece of rope, or the plastic piston stop that just stick through th plug hole up agains the cylinder wall, similiar to using a toothbrush as mentioned above.

 

[heimannm]

I have used...

The metal piston stop with no issues on several older Jonsered saws. No impact tools or getting carried away slamming it with a wrench.

I have also used rope on several saws with no issues there either, just be careful where the piston is when you feed the rope in to make sure it won't get caught in any of the ports.

I don't think I would recommend putting anything through the exhaust ports, there are just too many better ways that are safer.

I have plenty of old McCullochs that I just hold the flywheel with my hand and use the butterfly impact wrench on the flywheel nut or clutch. This is in spite of the fact the McCullochs all have a spot in the flywheel and cover where you can insert a pin to lock it in place.

By the way, plenty of those horizontal McCullochs have the spark plugs at an angle.

Mark

 

[Edge & Engine]

The metal piston stop with no issues on several older Jonsered saws. No impact tools or getting carried away slamming it with a wrench.

I have also used rope on several saws with no issues there either, just be careful where the piston is when you feed the rope in to make sure it won't get caught in any of the ports.

I don't think I would recommend putting anything through the exhaust ports, there are just too many better ways that are safer.

I have plenty of old McCullochs that I just hold the flywheel with my hand and use the butterfly impact wrench on the flywheel nut or clutch. This is in spite of the fact the McCullochs all have a spot in the flywheel and cover where you can insert a pin to lock it in place.

By the way, plenty of those horizontal McCullochs have the spark plugs at an angle.

Mark

You're right about the angled plugs.

Dolmar recommends stopping through the exhaust port, in fact they have a tool for it, it's basically small, flat wedge.

 

[Mitymouse]

I have used a metal piston stop many times without an issue. It does put a little "dent" in the piston though. However, after reading about the other problems people have had with piston stops I switched to using an air impact. I use a 3/8" drive impact and am very careful. In addition to not damaging the piston I have found this method to be quicker and easier.

 

[blsnelling]

If you're working on a saw with a cast in key on the flywheel, just remember to remove it before hitting the clutch with an impact wrench. Otherwise you're likely to shear it right off. Been there done that on a MS180 as well.

 

[PA Plumber]

Pull Plug.
Pull starter handle to get top of piston above exhaust and transfers.
Insert rope.
Remove clutch.
Takes about 90 seconds. I'm sure there are folks who can do this much faster.

 

[Lakeside53]

Pull Plug.
Pull starter handle to get top of piston above exhaust and transfers.
Insert rope.
Remove clutch.
Takes about 90 seconds. I'm sure there are folks who can do this much faster.

yes... and definitely take out the rope before you put the clutch back on - you'll be turning it though full rotation and it will fall down and catch the ports...

Hold the saw by the dogs in a big vice. Then you can use a decent size breaker bar.

 

[skid row]

I use the stihl plastic tool that comes with a new 200T. Works like a charm.

 

[Taxmantoo]

I will never again use a piston stop that screws into the spark plug hole. I know it's a tiny little piston, but I put a plastic screw in stop right through the crown of the piston on a MS180 simply trying to loosen the flywheel nut.

But that wasn't half as impressive as the time you used rope and horseshoed the connecting rod. :jawdrop:

 

[rngrchad]

impact guns....

I've never had to worry bout it, as I just stick my IR 3/8 impact gun on and spin'm off. Too easy. No taking spark plugs out or any of that stuffing rope in the cylinder.