Two stroke oils / Stihl Ultra / Stihl Motomix

[Stubby]

1 hour ago, Muddy42 said:

 

 

I am no expert on all this, waiting to hear from people who are!

TCD was the expert but sadly no longer on here . He was a fan of Red Line Racing 2t oil as am I .

Edited May 23, 2023 by Stubby

[petercb]

Came across this as about the only technical data coming up in search. Page 2 mentions mixture can separate at low temps and is irreversible. Ethanol doesn't help.

 

https://discount-equipment.com/library_files/2903.pdf

[Trailoftears]

No particular dog in this race! I've run dozens of 2 stroke small-engined machines over the last 40 odd years-mainly stihl and kawi machines.Often run hot and hard for extended periods commercially.Always used stihl red mineral oil @50:1 with no issues I could discern.Occaisonally had carbon breakaway shorting the s.plug intermittently at full speed on high hour stihl clearing saws-no big deal tho.As machines get more expensive and less tolerant re:E5?Changed to the semi synth stihl super green oil @40:1,again,no great differences noted commercially,I wouldnt use the stihl ultra just on price premium tbh.The super if bought at 5 litre quantity,pretty much compares to the price of a single litre price of the mineral oil anyway,and hopefully is a 'slight'upgrade.

[Trailoftears]

Also,no way could I even consider using the motomix cans regularly,even as a one man band,its not unusual to to use 20 litres of 2/+4/ a month.But if I buy a high-end 2/ machine-or 2 at the same time-I may buy a 5 litre can of moto just to treat/break them in-whether there is any sense/logic in that,I couldn't honestly say!

[Trailoftears]

Here's a mad thought/interesting experiment-buy your 5 litres of standard E10 petrol+add your chosen mineral/semi synth 2/oil,Then mix in a litre of moto on top!?That way,you are hedging your bets re:different 2/oils+diluting the ethanol content+making your moto go 5 times further too!Dont thank me,I can hear the applause from here 😄

[Crocky]

On 22/05/2023 at 13:48, Bob_z_l said:

Good point.   The US have their own mixes of fuel. ... 

Reaching out in the hope that  @Crocky has some comment....only based on the fact that he'll be looking at the insides of my 261 that has almost exclusively run on E5 pump fuel and Ultra 50:1 or as near as dammit. 

I don’t use Stihl ultra for the same reasons as is mentioned on that YouTube video. I use E5 fuel and Stihl HP super. I’ll let you know what the pistons like when I pull it apart but I’m pretty sure it’ll be coated like the one in the vid. 
 

I have pics of inside two cylinders, both the same saws. One ran on aspen’ and one on two stroke mix. I’ll find the pics and post them soon. I’m not a fan of aspen’ (personal preference) but it certainly burns cleaner. My only issue with it was the bottom end looked dry. 

Edited May 25, 2023 by Crocky

[Trailoftears]

A thought provoking topic.I'm no oil expert.But if you look at cars we have moved from mineral to semi synth,now fully synth oils.No modern car's service schedule would spec mineral oils I assume?Again,I assume fully synth oils flow/warm quicker due to their lower viscosity?So minimise start up/cold engine wear due to better initial warm-up/ early movement thru the engine.Which sounds logical....

[Crocky]

I don’t like how I typed aspen’ in and it automatically links to their website!

Edited May 25, 2023 by Crocky

[Crocky]

Edited it. Doesn’t link it anymore! 

[bmp01]

On 25/05/2023 at 22:17, Trailoftears said:

A thought provoking topic.I'm no oil expert.But if you look at cars we have moved from mineral to semi synth,now fully synth oils.No modern car's service schedule would spec mineral oils I assume?Again,I assume fully synth oils flow/warm quicker due to their lower viscosity?So minimise start up/cold engine wear due to better initial warm-up/ early movement thru the engine.Which sounds logical....

Oil spec on current car engines is all about fuel economy and emissions reduction (so thin oils for lower viscous drag) - not necessarily whats best for engine longevity. But then again modern engines are generaly good enough to last the warantee period and then some so theres some flexibility there.