HELP! Stihl 661...wtf...

[Wilhelm]

Here , I'll help Ya digest that!

 

[S&S_Work_Saws]

Maaaann, that little onesie baby outfit looking thing should catch on for some people.

 

[Wilhelm]

Maaaann, that little onesie baby outfit looking thing should catch on for some people.

Yeah, some of Gen-Y and onward will want to wear that!

 

[NZsaws]

Have you run all the wires and switches with a meter while jiggling them around? I had a harness that looked fine, tested fine but on the saw something kept cutting out. Turned out to be a clean break of a wire inside the sheathing…move it just right and no connection. 200t
Now I test wiring while moving them around

 

[Woodwackr]

Well?

 

[S&S_Work_Saws]

It's all reassembled and the problem seemed to be resolved with all the new parts and seals. The issue now is for some reason it has begun to shear flywheel keyways off. It always spins the flywheel to the advance. It's not during start up either. It's done it 3 times now while in the cut. Thinking it's just going to need a new flywheel.

 

[S&S_Work_Saws]

I've never seen a 661 lemon but I think this customer has the one bad one. It was only about 4 hours old and it got smashed under a tractor. Smashed the gas tank. The tank and carb and everything were replaced elsewhere. Another couple hours of run time and here we are.

 

[lehman live edge slab]

I've never seen a 661 lemon but I think this customer has the one bad one. It was only about 4 hours old and it got smashed under a tractor. Smashed the gas tank. The tank and carb and everything were replaced elsewhere. Another couple hours of run time and here we are.

Possible the flywheel suffered damage when it got smashed and may have caused all the issues including the miss.

 

[Woodslasher]

It's all reassembled and the problem seemed to be resolved with all the new parts and seals. The issue now is for some reason it has begun to shear flywheel keyways off. It always spins the flywheel to the advance. It's not during start up either. It's done it 3 times now while in the cut. Thinking it's just going to need a new flywheel.

Last time I had a saw that kept spinning the flywheel I fixed it by brakleening and wiping the chit outta the mating surfaces and using a piston stop so I could torque down the flywheel nut. Or you could lap the flywheel and the crank tapers.

 

[mrxlh]

Last time I had a saw that kept spinning the flywheel I fixed it by brakleening and wiping the chit outta the mating surfaces and using a piston stop so I could torque down the flywheel nut. Or you could lap the flywheel and the crank tapers.

Good suggestion, first I would Prussian blue the taper and see how bad the contact pattern is. If it needs to be lapped, lap it. Warming it up some before installing will get a better locking fit.

 

[Woodwackr]

Apply rubbing compound to the fw or shaft and spin.

 

[lehman live edge slab]

Apply rubbing compound to the fw or shaft and spin.

Never tried it but I bet valve lapping compound would work well. I never had many flywheel slipping issues but I did get an 025 once that had a hairline crack in flywheel taper. The crack opened up when tightening it and obviously wouldn’t ever stay. Hard to see the crack though

 

[Woodwackr]

Never tried it but I bet valve lapping compound would work well

Same basic thing. Lapping compounds probably come in more grit levels