Echo CS-3450 Chainsaw Sprocket Removal Method

[statsl]

I am a home owner and want to know how to replace damaged sprocket of Echo CS-3450 chain saw. Do I need special tool?
I really appreciate your help.

 

[lucky]

Hi there. I just repaired a cs 510(can't remember) for a friend. I needed a special tool/socket made for echo saws. One side is 19mm hex and the other is a three pronged type affair that turns your clutch. I think Baileys sells these tools. Good luck.

 

[Kneejerk Bombas]

You need to remove the clutch. It is threaded on with left hand threads, so it spins off backward.
Remove the spark plug, stick some small rope into the hole to fill the cylinder part way up, this will allow you to spin it off, and then back on, with out the crankshaft spinning on you.
The clutch has a nut shape center that allows you to use a socket wrench.
Once the clutch is off, the drum with the sprocket slides right off the needle bearing. You can put a dab of grease on the bearing when you re-assemble the saw.
When you screw the clutch back on, don't crank really hard, that just makes it harder next time you want to change it out. It has reverse threads so as you run the saw, it doesn't want to loosen up.

 

[statsl]

Thanks for your instructions. Both are very helpful.
I have a one question to 'Mike Mass'. You mentioned that 'The clutch has a nut shape center that allows you to use a socket wrench'. It has round shape center and I don't how to open with a socket wrench'. Do I need a tool/socket which 'lucky' mentioned?

 

[HiOctane]

Thanks for your instructions. Both are very helpful.
I have a one question to 'Mike Mass'. You mentioned that 'The clutch has a nut shape center that allows you to use a socket wrench'. It has round shape center and I don't how to open with a socket wrench'. Do I need a tool/socket which 'lucky' mentioned?[/QUOTE
There is special tool to remove the clutch like a plate with 3"fingers"that goes between each shoe .Without this,its hard to unscrew because you can break the clutch center.

 

[Lawn Masters]

You do need the special tool on the Echo saws to remove the clutch, Baileys sells em. ask Grande Dog about it, he'll hook you up.

 

[rlwj]

You do need the special tool on the Echo saws to remove the clutch, Baileys sells em. ask Grande Dog about it, he'll hook you up.

I made a simple tool to do the job out of junk from around the shop: One piece of flat steel 1/8" thick, 2" wide, a few feet long, and three 1/4"x20 3/4" bolts and nuts.
I will try to upload a few pictures, but basically:
What you need is to have three "pins" stick out that engage the clutch in the saw, sticking out from something you can use to turn that clutch. I drilled three 1/4" holes in that flat bar, equally spaced around a circle one and an eighth inch in diameter. Put the bolts through from one side, tighten down nuts on other side. The three bolts stick out far enough to engage the clutch: They could be slightly shorter and still reach far enough beyond the nuts, but much longer and leverage would be bad on the end of the bolts.
I put some 5/16" braided nylon rope in the combustion chamber, snugged the piston up using the starter rope, engaged those three bolts, and trivially unscrewed the clutch mechanism. The bar I had, about 3 feet, was far more leverage than needed.
Here are pictures of the whole thing and both sides of the working end.

 

[rlwj]

I made a simple tool to do the job out of junk from around the shop: One piece of flat steel 1/8" thick, 2" wide, a few feet long, and three 1/4"x20 3/4" bolts and nuts.
I will try to upload a few pictures, but basically:
What you need is to have three "pins" stick out that engage the clutch in the saw, sticking out from something you can use to turn that clutch. I drilled three 1/4" holes in that flat bar, equally spaced around a circle one and an eighth inch in diameter. Put the bolts through from one side, tighten down nuts on other side. The three bolts stick out far enough to engage the clutch: They could be slightly shorter and still reach far enough beyond the nuts, but much longer and leverage would be bad on the end of the bolts.
I put some 5/16" braided nylon rope in the combustion chamber, snugged the piston up using the starter rope, engaged those three bolts, and trivially unscrewed the clutch mechanism. The bar I had, about 3 feet, was far more leverage than needed.
Here are pictures of the whole thing and both sides of the working end. View attachment 506274 View attachment 506275 View attachment 506276

Well that worked well, and the new carburetor that I installed took care of the other reason I was working on the saw (that I could not get it to start even after I rebuilt the carburetor. With the new carb it started right up.)

BUT BEWARE: After I tightened the clutch in place, counter clockwise and all that, to what seemed tight enough. (And remembering that the left-hand threads should make the joint tighten up in use.) I started it, no chain on it, revved it up a few times, and to my astonishment the clutch/washer/sprocket assembly spun off and the new sprocket rolled about 25 feet away! Fortunately the pieces stopped in some of the few places where you can see the floor of my messy shop, so it was easy to find those three pieces (the roller bearing had stayed on the shaft), clean them up, and reinstall them. I have yet to re-tighten it. I am pretty sure it was as tight as it should need to be for real use, as distinct from just revving it up with no chain.
But the moral of this is that you shouldn't rev it up, down, up, down, etc. with no chain on it! The clutch assembly gets to spinning, has a fair amount of momentum, and unscrews itself when the saw suddenly slows down. The "it will tighten itself up" applies when the motor is driving the clutch and chain, but when there is no resistance from the chain to slow the clutch down quickly when you let off the throttle, things are backwards, the clutch is "trying" to drive the crankshaft rather than the other way around, and in that direction it is "unscrew" rather than "tighten"! I am confident the rev up and down would not hurt IF the clutch had been screwed on there for hours of use, like it usually is, and glued it in place. But don't do this with nice clean threads there! I think I may even put a drop of thread locker on there when I do tighten it up again.
Bob Wilson

 

[0x00]

This is unbelievable. I am scrapping an echo that a crew ran over with the truck and stopped dead in my tracks when i saw the stupid 'inboard sprocket-cup' and 'no way to service it without special tools.' Does Echo ship the saws with the clutch tool? Thank god I never acquired any Echo keepers. I'll 'beat it off with a cold chisel' and toss it in the recycle bin. Is there any value in the undamaged parts I took off or are these things 100% disposable not-even-expected-to-last-one-sprocket saws?

 

[ray benson]

This is unbelievable. I am scrapping an echo that a crew ran over with the truck and stopped dead in my tracks when i saw the stupid 'inboard sprocket-cup' and 'no way to service it without special tools.' Does Echo ship the saws with the clutch tool? Thank god I never acquired any Echo keepers. I'll 'beat it off with a cold chisel' and toss it in the recycle bin. Is there any value in the undamaged parts I took off or are these things 100% disposable not-even-expected-to-last-one-sprocket saws?

The 3000,3400 and 3450 saws run and run. Very reliable as long as they are not run over. Make the sprocket tool out of an old socket or like rlwj did in post 7 or buy the tool. Learn how to take off the clutch, no big deal.