The Forestry Forum

When my saw would not start because I flooded it (Husky 365) - my fault - I pulled and cleaned the spark plug. Around the electrode it was loaded with black carbon (?) that almost looked like broken ceramic. The plug was not worn at all and was still gapped at .025.  I run my oil mix at 40:1 instead of the 50:1.

Considering I use the saw mainly now for chainsaw milling, is this spark plug build up normal or does the saw have further issues. I rarely put my saw away "wet" as in I regularly grease it and clean the filters and all the spaces. So, I doubt it has a filter problem. Seems to run okay again.

The chainsaw is my first 2 cycle engine I have owned, I am more use to gas and diesel engines, so I am not sure what is normal for the plug.

What are norrmal conditions for a used spark plug ?

40:1 is heavy and will contribute to plug problems. I suggest 50:1 using a quality oil such as Husqvarna. I use OPTI-2 at 100:1 in my Husky 345 with no problems. I certainly was uneasy at first but have experienced no overheating.
The plug should be light brown in colour after hard use, no excessive idling. Grey or white indicate over lean and trouble.

Quote40:1 is heavy and will contribute to plug problems........The plug should be light brown in colour after hard use, no excessive idling. Grey or white indicate over lean and trouble.

Sawguy, I mostly agree with the last part of your statement although I like a darker brown better, but 40:1 is not the cause of Rebocardo`s carbon buildup. His carb is more than likely set too rich. I run everything at 32:1 now whether using MX2T, Husky, or Stihl mix and my plugs are free of chunks or heavy buildup.

Russ

Thanks!  I am going to keep watching the plug(s) and if I can not get/keep that brown color I might bring it to the dealer for an adjustment to make sure I am not running too rich or too lean.