samaritan
ArboristSite Operative
Forget the piston stop or the rope, I used my Ryobi impact drill and the clutch came off in a jiffy, same with the flywheel
Forget the piston stop
- Thread starter samaritan
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dont come complaining when you snap a crank.
just because you got away with it does not make it a safe and good way of doing it.
just because you got away with it does not make it a safe and good way of doing it.
Yep! Been there and got a ribbon to prove it. First starting out as a mechanic, popped end of crankshaft off tightening nut on flywheel on lawnmower engine with impact !
Also possible to snap flywheel key. Especially on cast in keys.
Shops don’t use impacts for that job cause we can charge more billable hours by using piston stops with hand tools instead of impact gun!
on a serious note-
broke a crank end 30 years ago doing that, now impact collects dust
on a serious note-
broke a crank end 30 years ago doing that, now impact collects dust
Put it back on fingers or manually, start engine and engage chain brake.
I would take "impact drill" to mean 1/4 hex drive, kind of small.
To use a piston stop one probably should see in the manual how, where. what their stop looks like.
For my Echo 361p the accessory clutch tool fits the scrench and a blow from an 18" 1x2 board.
I don't take flywheels off lately change sprockets.
I would take "impact drill" to mean 1/4 hex drive, kind of small.
To use a piston stop one probably should see in the manual how, where. what their stop looks like.
For my Echo 361p the accessory clutch tool fits the scrench and a blow from an 18" 1x2 board.
I don't take flywheels off lately change sprockets.
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Dunno.
If there is no rolling resistance, no sudden stop capability (like crank rotating with the impact wrench until close to TDC and contacting a piston stop) I do not see a lot of possibility for a small battery impact wrench to twist off the crank end. 1/2 inch air powered wrench- all bets are off!
If it is a running saw in good condition and clutch is coming off to be replaced, or access a drive sprocket- I use an 18V impact wrench- touch wood it has worked okay thus far. On locked up saws, old wrecks, saws with obsolete cranks, or it needs the addition of a piston stop- I don't.
Like most "cheats" you use them until you cannot get away with it!
Would you run more of a risk if the threads are rusted that would require more breaking force? Soaking with PB Blaster for a while...
Makesure the threads are not the cause of possible snapping off the end. I use either method as what I think would have the best success.
Makesure the threads are not the cause of possible snapping off the end. I use either method as what I think would have the best success.
Never broke anything yet with my Milwaulkee 12 V impact .Never used a piston stop or rope ever.
I use a 1/4 drive air gun on just about all of mine ..works well !
Ernie
Ernie
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The piston stop method is more likely to do the damage.
After 21 years on this forum, I have seen a lot of bad advice leading these guys to screw up their saws.
If one is real bad, I will seek to do the piston stop, but that is very rare.
The twisted off cranks that I have seen were done with the piston stop method.
The fanwheel on big blowers need the piston stop method.
After 21 years on this forum, I have seen a lot of bad advice leading these guys to screw up their saws.
If one is real bad, I will seek to do the piston stop, but that is very rare.
The twisted off cranks that I have seen were done with the piston stop method.
The fanwheel on big blowers need the piston stop method.
increasing
ArboristSite Lurker
Dismantling with or without a nut driver... Dismantling with a nut driver as long as you know whether to screw clockwise or counter-clockwise is no problem. Go ahead! HarleyT shows this in a nice way, also how to disassemble without a puller (special tool) as long as you have feeling and insight into what you are doing as shown in the video.
I use a clean piece of soft nylon rope.
if you use rope, best to insert a loop end into plug hole with end piece sticking out of plug hole, that way if rope clips port and gets cut, you may not realize it will end piece, but if looped, it will cut loop end and you will know if a piece of rope is inside engine when you pull rope out
I have used impact with no issue thus far, but worth a second thought...
Use a 3/8 or smaller impact gun, blip the trigger while holding the flywheel still in your hand. I don't use a rope or piston stop because I do not like the idea or foreign material in the engine or the load it will put on the rotating assembly, bearings etc
I use a piston stop pretty much exclusively. It’s a tool that exists for a reason. Yes there’s other ways of stopping a piston. If you understand what it is and how it’s meant to be used it’s fool proof. Don’t EVER use a piston stop with a impact gun. That’s a sure fire way to break something.
By holding the flywheel how much of a risk is it to shear a shear pin?
Flywheels with the molded aluminum key seems easier to shear.
Some person in our saywer group decided to fix our Stihl 361. Needed a new clutch pack. I rescued it from the basement and found the clutch never got removed, but the flywheel aluminum key was sheared. When holding the flywheel did not work the exhaust was removed and a screwdriver was used as a piston stop in the exhaust port. Yes a notch was djggered into the piston and cylinder wall.
It was abandoned and hidden in the basement. I'm sure the person did not know the threads on the clutch was righty loosey...
Flywheels are tapered for interference fit not relying on the key to hold it in place only for orientation during assembly so if it is installed and not loose the chance of sheering the key is slim to none.
