How to remedy a worn spur sprocket?

[dougand3]

Best not this way....I got a Poulan 1800 Super off CL. Came with 2 chains. The chain wouldn't turn well - grabby. I look closer and sprocket is worn out. When the sprocket wore so much that the proper 52 DL chain could not be tightened...he put on a 50 DL chain.
Time for a new sprocket.

 

[CTYank]

Wow! Hard to believe it worked at all. Assuming it's held captive on the crank by the clutch, you'll need a clutch removal tool and replacement spur sprocket/drum & bearing. You might want to get replacement washers- hard to check their condition with clutch in place. Some of the washers are dished and specific to that model saw.

Might be a good idea to see if you can get a combo drum&rim clutch. Can't hurt. Get a spare drive rim with it. Saves unnecessary drum changes.

 

[dougand3]

Yeah, I'd rather have a rim but they are scarce. I finally got a Poulan clutch tool....Got tired of putting saw in corner, hold feet against it, keep a long screwdriver on clutch as you whack it. LOL

 

[blades]

I made a nylon plug to replaced the spark plug to hold the piston a bit before tdc

 

[dougand3]

Nylon plug is a good idea. I use rope but you need to start piston 3/4 of way up or you can get rope caught in the exhaust port.

 

[kevin j]

Hold the piston as far down as possible just above ports.
As it approaches TDC the angle of rod to crank approaches a straight line. It acts like s toggle linkage on a vise grips. It takes very high forces to resist the torque of turning the clutch tool. Those high forces can bend rod or punch hole in top of piston where piston stop contacts it.

 

[CountryBoy19]

Hold the piston as far down as possible just above ports.
As it approaches TDC the angle of rod to crank approaches a straight line. It acts like s toggle linkage on a vise grips. It takes very high forces to resist the torque of turning the clutch tool. Those high forces can bend rod or punch hole in top of piston where piston stop contacts it.

This ^^^

Near TDC the linear force on the piston is very large, you want to get as far away from TDC as you can...

That being said, the best way to remove clutch is with an impact gun. I've successfully removed the clutch on my saw using nothing more than an impact-driver meant for driving screwing (not an impact gun meant for loosening bolts etc). Of course, if you have an actual impact gun that is even better.