261 piston running on Redline..

[Pinkfoot]

I have only ever run this saw on Stihl Ultra and Redline 2 stroke oil.

It looks really good to me , though I am no mechanic.

[adw]

Fair amount of carbon on the edges of the ports and the port itself looks quite black and rich.

[TimberCutterDartmoor]

Fair amount of carbon on the edges of the ports and the port itself looks quite black and rich.

 

Definitely science lessons missing here. Combustion in particular. Gas cooling, FS uhc in stoichiometry conditions, yada yada yada.

 

Compare the ring lands with the waste passage.

[GardenKit]

To be quite honest, as ADW says, there is nothing particularly clean about that piston and port. OK its not the filthiest I have seen and is perfectly acceptable.

 

But of course most of the ones I see are run on Aspen which will obviously always give cleaner results than petrol purely because of the absence of ring-formed aromatic hydrocarbons, so I may have fairly high expectations.

[spudulike]

Aromatic hydrocarbons......That's No 22 at the local Chinese Restaurant:001_tongue:

[Stubby]

Aromatic hydrocarbons......That's No 22 at the local Chinese Restaurant:001_tongue: