Help getting the clutch off a 3120XP

[Parkerpusher]

Trying to get the clutch off of my 3120 so I can change the .404 to 3/8”. The plastic piston stop I have Is just a little too short, the piston makes contact with it and stops it but not enough to get the clutch off. I think it’s making 1/16” or less of contact and it just deforms the plastic and continues the rotation. Any good ideas to extend what I have without losing something inside? Or another idea? Im not thinking great today and figured asking here couldn’t hurt. Thanks.

 

[ammoaddict]

I use starter rope stuffed in the cylinder on the upstroke.

 

[Jethro 2t sniffer]

Impact gun.

 

[Parkerpusher]

Impact gun.

Good idea

 

[Parkerpusher]

I use starter rope stuffed in the cylinder on the upstroke.

Thought about that, but I don’t have anything clean enough around here right now i would use. There’s a ton of room above the piston when its at TDC i would have to use lots of rope

 

[rbrown]

Be aware that it’s reverse thread.

 

[Woodslasher]

Impact gun.

Make sure you have some means of keeping the clutch from flying, I used just an impact on the clutch (on a 3120 oddly enough) and when it gave the clutch flew about 8 feet to my right and took a chip out of the concrete wall about 7-8 feet off the ground. If that'd hit my head I'd have at least gotten a lump.

Thought about that, but I don’t have anything clean enough around here right now i would use. There’s a ton of room above the piston when its at TDC i would have to use lots of rope

When I was rebuilding a 3120 I found that the only piston stop I had that was long enough was a genuine Husqvarna one. Unfortunately the cheap-azz a/m piston that was on the saw originally buckled and cracked when it hit the stop, hence the plain impact I mentioned earlier. The genuine piston I installed withstood the pressures of the piston stop without harm, fyi.

 

[pioneerguy600]

Don`t use a piston stop at all if using an impact driver, al that is needed is to leave the sparkplug installed, the impact will break the clutch free by just using the compression . The crank can be twisted if a piston stop is used when running an impact with something stopping the piston, the crank on a chainsaw is just a press fit that can slip out of sync.

 

[Maintenance supervisor]

Thick starter rope.

 

[ammoaddict]

Thought about that, but I don’t have anything clean enough around here right now i would use. There’s a ton of room above the piston when its at TDC i would have to use lots of rope

The rope will get between the piston and squish band and hold it.

 

[Parkerpusher]

All good advice and warnings. Will give it a go tomorrow . Thanks guys

 

[Woodslasher]

Don`t use a piston stop at all if using an impact driver, al that is needed is to leave the sparkplug installed, the impact will break the clutch free by just using the compression . The crank can be twisted if a piston stop is used when running an impact with something stopping the piston, the crank on a chainsaw is just a press fit that can slip out of sync.

Yeah, I should have specified that you only use a piston stop when you're using a socket wrench/torque wrench and never with an impact gun. If you're using an impact gun you don't need a piston stop.

 

[Parkerpusher]

Got it. Will try tomorrow with plug back in and impact. If that doesn’t work I will try rope and a ratchet.

 

[Maintenance supervisor]

Take your starter recoil off also as insurance.

 

[cbfarmall]

I have knotted starter rope for the big cube saws.

Edit: on my 090, I've had to put the knots in knots.

 

[ammoaddict]

Got it. Will try tomorrow with plug back in and impact. If that doesn’t work I will try rope and a ratchet.

The impact will work.

 

[TRTermite]

I used a cheap plastic piston stop. As it hit top dead center it rolled over. bearings were fine before that not after it took out both of them. this was a Stihl 056 Magnum (higher serial number). All said and done the bearing cages were PLASTIC and they shattered/crumbled. My advice would be impact if possible and get enough rope in there so you are nowhere near top dead center, but don' let the rope get in the transfers/intake/exhaust ports.

 

[TRTermite]

With the impact method just blip the trigger and avoid letting the crank spin much at all. The hammers will do their thing and the crank and clutch shouldn't do as Woodslasher mentioned.

 

[Parkerpusher]

Just ran over to the shop. Used a little 12v impact and it worked. Took a bit though, that clutch was ON there. Thanks for all the help guys I appreciate it.

 

[Parkerpusher]

Ready to go for Monday