066 project. to split or not to split?

[nilzlofgren]

I was planning on splitting my case to start my project from scratch. Then I got to thinking, If it isn't broke, maybe I should'nt fix it. There is no vertical movement between the crank and the connecting rod, and the crank bearings seem fine, as there is also no vertical movement of the crank. There is however, side to side movement between the rod and crank. It will slide from one side completely to the other, which in reality. only about 1/16 or 1/8 inch. So maybe I can start my project from there?

 

[thompson1600]

I usually agree with the "if it ain't broke don't fix it" methodology. And you could probably start out with a fresh rebuild from where you are. If I bought the case used, or didn't know it's full history, I would split the case. That way I can check the bearings. Make sure the bearing races are in good shape and you haven't got a spun bearing. I can check the case sections and put in a new gasket. It is pretty easy to split the case and cheap to get new gaskets. If I had it stripped down that far I would keep going so I had a complete rebuild and knew all the parts were good. Plus you can then paint it up with Stihl paint and make it look perty.

 

[Timberhauler]

If you are modifying this saw and have the budget,I would go ahead and split it.

 

[nilzlofgren]

Thanks I will split it.

 

[Lakeside53]

I was planning on splitting my case to start my project from scratch. Then I got to thinking, If it isn't broke, maybe I should'nt fix it. There is no vertical movement between the crank and the connecting rod, and the crank bearings seem fine, as there is also no vertical movement of the crank. There is however, side to side movement between the rod and crank. It will slide from one side completely to the other, which in reality. only about 1/16 or 1/8 inch. So maybe I can start my project from there?

Side to side on the rod is absolutely normal. I wouldn't split it unless there is a reason.

 

[timberwolf]

That is not a simple fix any way, even if you could get a main bearing ther is all the crank pressing and realigning to deal with.

Never looked is the 066 a 2 piece or 3 piece crank?

 

[Lakeside53]

The crank is two pieces plus the pin, assembled and electrically fused, but... what is being described is perfectly normal. All stihl cranks have significant side play of the rod on the big-end roller bearing.

 

[timberwolf]

I don't like the sound of electrically fused. Sounds hard to work on if someone had such a notion for some undisclosed reason. But then again, if such a person was removing the king pin, the likely would not be putting it back in the same place.

 

[Lakeside53]

They are never worked on (in the normal course of repair) - just chucked (rarely go bad). Stihl doesn't even offer a replacement bearing, so it would need to be tracked down, assuming its a standard size.