bullittman281
ArboristSite Operative
I've just finished putting a new top end on my MS360. This saw has been a long running saga. A co-worker gave to to me a number of years ago “running”. The saw was filthy and needed a new piston/cylinder. Its sat in the shed disassembled for years until a while back I got motivated to fix it. I initially stuck a Meteor top end on it and ran with it. Performance was disappointing compared to the 361s at work. Based on some insight from an 034 super than I fixed I got nervous about the bottom end give the extreme usage this saw had seen. Same as the other 034 and parts 360 the main bearing plastic cages were toasted. Yesterday I finally got all of my parts in to put it all back together with OEM parts. New mains, seals and Stihl top end.
To be honest I’m a bit disappointed in the Stihl cylinder given the extreme cost. Instead of being made by Mahl it is Stihl in house and appears to be made in Brazil. The casting work is as rough or rougher than the Meteor. There was plenty of roughness in the transfers. Port shapes were radically different than the Meteor and somewhat different than the old cylinders I have. I don’t have a degree wheel to compare timing but its interesting to look at. The exhaust port does look far better in that the top and bottom of the port is curved and not flat. The port de-burr work was sufficient but there certainly wasn’t any extra time spent on it. Squish with a gasket was an overly generous .050”. The ring gaps were .011” and .012” so those looked good. The piston looked really good.
I’ve ran it for a few minutes and made a couple of cuts. I need the weather to warm up and dry out before I can really go test it. Even with the minimal run time the rings have seated FAR better than any of my other rebuilds with used cylinders. I don’t know if Stihl rings are softer or better machined than Caber or if cylinder roundness is a thing and the Stihl cylinder is better but they do seal well immediately. The saw hangs from the pull rope better that any others I’ve worked on. Compression hot and cold is ~140 at 6500 feet. I pulled the base gasket for a squish of .020-.025”. Much better than .050”. So far though I’m happy. I’ve got an all OEM MS360 PRO. Next week I can see if it cuts any better than with the Meteor top end. Unfortunately I did not think to get any pics of it going together.
Bullittman
To be honest I’m a bit disappointed in the Stihl cylinder given the extreme cost. Instead of being made by Mahl it is Stihl in house and appears to be made in Brazil. The casting work is as rough or rougher than the Meteor. There was plenty of roughness in the transfers. Port shapes were radically different than the Meteor and somewhat different than the old cylinders I have. I don’t have a degree wheel to compare timing but its interesting to look at. The exhaust port does look far better in that the top and bottom of the port is curved and not flat. The port de-burr work was sufficient but there certainly wasn’t any extra time spent on it. Squish with a gasket was an overly generous .050”. The ring gaps were .011” and .012” so those looked good. The piston looked really good.
I’ve ran it for a few minutes and made a couple of cuts. I need the weather to warm up and dry out before I can really go test it. Even with the minimal run time the rings have seated FAR better than any of my other rebuilds with used cylinders. I don’t know if Stihl rings are softer or better machined than Caber or if cylinder roundness is a thing and the Stihl cylinder is better but they do seal well immediately. The saw hangs from the pull rope better that any others I’ve worked on. Compression hot and cold is ~140 at 6500 feet. I pulled the base gasket for a squish of .020-.025”. Much better than .050”. So far though I’m happy. I’ve got an all OEM MS360 PRO. Next week I can see if it cuts any better than with the Meteor top end. Unfortunately I did not think to get any pics of it going together.
Bullittman
