Vintage Stihl

All depends on what I find when I get it out. If it's in decent shape, yes, some scotch brite and new rings will be the ticket. If it has more damage than I'm comfortable with (from the removal process) I'll replace it.

 

Well, I'm at a standstill. I just can't get the cylinder off of the piston. Other than trying various products/mixtures to get lubrication in there I just don't know what to do. I've used a half can of PB Blaster, heat cycles, kicking, screaming, cursing, etc.

I got it where it is by placing wood between the cylinder & case and cranking on the flywheel nut to bring the piston 'down', than adding wood, etc. Now it's solid to a point where I'm not comfortable putting any more torque on the flywheel nut for fear of twisting off the end of the crankshaft.

I think my next step is going to be to clean it as best I can and then rig it up so I can leave the p/c submerged in Marvel Mystery oil or something similar for a week so that I know it can get to every area possible...

 

Is it possible a ring is snagged inna port?

 

The rings are below the intake port. I can't even rotate the cylinder...

 

Oh Yea I forgot you said that.

 

You beat me to it , I have had great luck with pb blaster

 

It's SOLID, I can't even get the cylinder to rotate by putting enough force on it that I'm worried about damaging the con-rod bearing or possibly snapping the con-rod altogether.

I have pretty clear access to the bottom of the cylinder. With the top of the piston just above the intake port most of the skirt is showing below the cylinder base.

The piston never moved freely, but with a little bit of force I got it to move downward to this point, but then it hung up. I know to those reading this it probably seems like an easy fix, but rest assured this is not an everyday situation. Given how stuck it is, the scarcity of parts should something break, and the fact that these saws have studs for cylinder mounting that stick up from the base (not removable screws like most modern saws) adding to the challenge, it's really a sticky wicket I'm in here...

I have started to consider splitting the case just to get away from those damm mounting studs, but that's going to be my absolute last resort as to avoid putting the bearings in danger.

Keep the questions & advice coming though . . . I'm all ears!

 

Well having studs in the case ruined my idea of trying to rotate the cylinder on the piston to start working the rust, stuck ring or whatever is hung up.

 

grasing at straws... could you put the head back on and put a fitting on the spark plug hole and hook up a pressure washer, blow it out like a clogged drain?

 

Piston is below all ports so I doubt that would get you very far bd.

 

Good point, I guess you'd just have a funny shower head.

 

Yeah, I've use jam nuts for case studs the same as bar studs and would be comfortable doing that in this case. However, I have not done that yet as I haven't convinced myself I won't need them again before this is over. Running the piston back up into the cylinder is something I'd like to do . . . but that damm thing is rock freaking solid where it is and I just feel like any more movement (up or down) is going to cause damage and I'd just assume keep said damage below the ports...

As they say though, something's got to give! I'm going to have to try one of these things eventually anyway.

 

It's been like this for a long time, be patient and think your way through it.

 

Tonight I positioned the saw hanging upside down with the piston/cylinder submerged in a tub of Marvel Mystery Oil. I'm going to let that marinade for at least a week and then we'll jump back in the ring.

That said, I won't have much to report for the diary. Again though, please feel free to throw any suggestions over the fence. If I say I've already tried it or have a reason I don't want to doesn't mean I don't appreciate it. ALL feedback is appreciated . . . this is new ground for me. I've had far less trouble pulling the cylinder off of a badly seized saw...