Piston of Stihl MS361 Clone Kit Saw

[arto98607]

Hi all,
I am a homeowner and could not justify buying larger new professional OEM saws for my occasional use so couple of years ago decided to build couple of clones since my Husky 162 and Stihl AV031 are pretty old.

I built MS660 and 361 clones from kits and both have worked out very well, except some difficulties in tuning the 361 due to very restricted muffler it came with, making it difficult to hear "burbling" stop and engine cleaning up when loaded. Apparently others have had similar issue with MS361's.

No such difficulty at all with the 660 kit saw.



I have now switched 361 to "Rippa" muffler and it's easy to hear burbling stop when saw engine is loaded.
Photo below was taken while changing mufflers.

Question:
Are the vertical "scratches" just above the top piston ring normal? (Please zoom in on the photo)




New muffler, no more trouble tuning in:

 

[dieselscout80]

What is a clone MS361?

 

[arto98607]

OK I have edited the post title!

Farmertec MS361 kit of complete 100% set of spare parts for Stihl MS361

 

[dieselscout80]

Thanks

 

[xyz123]

It's a G366 farmertec copy.

Mine ran as good as my oem one did with muffler mods on both. These need it IMHO.
I just do free no cost muffler mods.

They seem to be more of the problematic clones for owners though.

 

[xyz123]

I honestly can not see anything wrong with your piston and rings in your pic.

 

[arto98607]

I agree the rings look great, but if you zoom in the photo you will see what I think is a band of short vertical scratches indicating metel to metal contact.

Just wondering if that is normal?

 

[ruffdog]

Many moons ago I was involved in a reseller of cheap big-bore kits and aftermarket cylinders. We found the quality was spotty and the cast seemed dirty with sand. Those scratches sure look like it is from "dirt" but it could also be from the quality of the mating parts like the cylinder wall.

 

[arto98607]

Many moons ago I was involved in a reseller of cheap big-bore kits and aftermarket cylinders. We found the quality was spotty and the cast seemed dirty with sand. Those scratches sure look like it is from "dirt" but it could also be from the quality of the mating parts like the cylinder wall.

I agree and don't think it's normal to have markings like that!

Oh well, the saw works good and I will keep using it but will soon order better quality cylinder & piston.

Used it to fell about 70 hybrid poplars just before taking the photo of the piston.


Not looking for big bore, just regular MS361 47 mm set - I am open if anyone here has suggestions on suppliers?



Felling was the easy part, now the real work begins:

 

[dodge man]

I agree, the scratches don’t look right but they don’t extend down onto the rings. A pic of a MS 250 that had a badly damaged piston and rings, yours doesn’t look near as bad.