Taryl vs the BR600 Bushing

[Merle Nelson]

I had never heard anything to question Stihl Ultra oil. So for those of us who are just catching word of it, again thanks for putting this up.

I mix it ar 40 to 1 so maybe that has helped a bit through the years and appears to me to not carbon up at that mix. The orange still oil carboned up and killed a few saws.

 

[Bart_]

Interesting that the generator that ran cooler had a plug a bit darker - exactly the result for plug reading and jetting. Brings the topic of oil, oil mix ratio and jetting (for load and ambient) into the mix. I once mixed 100:1 oil at 80something to one and smoked like a bugger and which would show up as overrich by traditional plug reading. Had some other oil specced at 16:1. Ran even cleaner than the 100:1.

So maybe I'm saying testing has to be per usage spec, but that contradicts the set 150:1 cylinder wall test spec. Guy didn't mention anything about zinc which I think is a big antiwear factor. And then there's operating condition, mild, mid and severe both with respect to temperature and pressure/shear, His test was probably mid and his contact wear test was definitely cold. If it were me I'd research the topic beyond the well intentioned, appreciated testing and opinions presented.

Cleaning the spark arrest screen and port/muffler/header area is just expected routine unavoidable maintenance for dirt bike guys.

Anecdotally I've got quite a few years trouble free from the orange bottle Stihl oil.

 

[Bart_]

Google found a post by a knowledgeable fellow named Cujet on Bitog, who I recall from dirt rider.net back years ago:

How 2 cycle aircraft engine oil works, what makes a good 2 stroke oil, two stroke air cooled engine oil, two stroke liquid cooled engine oil.

I'll risk a slap on the wrist and link a Bitog post (nerd power!!):

https://bobistheoilguy.com/forums/threads/multi-purpose-2-cycle-oils-how-is-this-possible.181107/