Stihl 361 Junkyard Zombie Mutant

[Powerstroke Cowboy]

Sad turn of events Caleb. Sorry to see and hear.

Is there a chance the bore is out of round (slightly egg shapped) and that caused the ring to extend into the port more than normal and snagged?

 

[David Young]

Not much more to see really.
View attachment 422311View attachment 422312

If you look close, the ring deformed the roof of the port as well.

This is a first for me. I’ve seen hung rings, but never had it happen to a saw I messed with. I’m not sure why it happened. The floor of the exhaust was stock. I did a very light chamfer, but otherwise it was factory. This jug had been scored before I got it. Some of the scoring was in that area and there was a minor spot just below the lip of the port that was too deep to sand away. I disassembled, raised the ports, radiused the chamber and reassembled in about 4 hours yesterday. It’s possible I got funk behind the ring, though I’m really careful about that. Chock it up to haste and junk parts. I’m definitely bummed about it, but not surprised. I wish it had made it a few weeks though. I was hoping to bring it to @davidwyby’s G2G.

clean it up and keep going... what do you have to lose? the radius on the bottom of the exhaust is more important than on the top. single ring pistons are often tougher in this aspect.

 

[thedude74]

Any more progress Caleb?

Bump for the posterity of lightweight saws with big block horsepower.

 

[Ketchup]

Any more progress Caleb?

Bump for the posterity of lightweight saws with big block horsepower.

Nothing exciting. I smoothed out the damage and put in a new piston. It fired and ran, but then it sprung a leak. I’ll pressure test today. I’ll be doing a new jug when I have time.

 

[Ketchup]

Had to re-do both seals and bushings. The FW side wasn’t tall enough, the PTO was too tall and deformed an alarming amount. I’ll try another round with brass. I may end up needing to use
steel. The oiler gear also stripped and the clutch washer came loose. Ugly in there.

 

[64poncho]

Had to re-do both seals and bushings. The FW side wasn’t tall enough, the PTO was too tall and deformed an alarming amount. I’ll try another round with brass. I may end up needing to use
steel.

I think using steel for the bushing would be better. What are you sealing the bushings to crank with? Dirko or LocTite?

 

[Ketchup]

I think using steel for the bushing would be better. What are you sealing the bushings to crank with? Dirko or LocTite?

LocTite Green. I’m not sure why I did the bushings in brass. They’re already in though, so I’ll give it a second chance.

 

[64poncho]

LocTite Green. I’m not sure why I did the bushings in brass. They’re already in though, so I’ll give it a second chance.

With the length of the bushings corrected, should be ok.

 

[Shane¹]

Any updates I want to see this contraption work got to love a crazy hybrid

 

[Ketchup]

Any updates I want to see this contraption work got to love a crazy hybrid

No time right now. I’m trying to get my race chains up to snuff.

 

[Powerstroke Cowboy]

No time right now. I’m trying to get my race chains up to snuff.

Times a precious commodity that can't be manufactured.