Stihl 4-Mix Oil?

[bwalker]

As far as I'm aware 2-Stroke FD oils can be used in place of FB oils.

3.2 Basic Concept of the Performance Classification

The performance level of 2-cycle oils is classified into three grades, FB, FC and FD, according to the test results based on the above-mentioned four JASO 2-cycle oil test methods. These are defined as FB, FC, FD from lowest to highest performance. The FC grade is defined for low smoke 2-cycle oils superior to FB with regard to exhaust smoke and exhaust system blocking. FD grade is defined as improved version of FC in terms of detergency performance at high temperatures.​

It doesn't really work like that. Many marine oils can pass FB, yet should never be used in air cooled equipment.

 

[bwalker]

So is the solution to not get a 4mix engine?

Get a legit 4 stroke, or a legit 2 stroke, but don't try and combine them?

I agree with this.
The 4 mix takes the bad traits of a two cycle and forces them into a four cycle.
It's just a poor design.

 

[Squareground3691]

Ethanol really has nothing to do with it. And 800T is probaly one of the poorest choices you could use in a 4mix. It's higher in ash content than a FC or FD oil. In addition it has a high end point because it's designed for hibstress motors. A low stress, low temp 4 stroke is not the best match for this oil.

Ethanol doesn’t gum up carburetors and destroy their diaphragms , ? Interesting that 700 will be going on 7 years at end of this year , haven’t done anything to it , been flawless from the time I purchased it , used the same oil for over a decade ,

 

[bwalker]

Sorry. I think Opti-2 was what I was trying to remember.
Anyhow, I have gotten two free BR-700 from lawn care contractor addicted to it because the city uses it I think.

Just take a Dremel tool with a brush and clean the valves and valve stems and back like new for my time, which is pretty much worth nothing.

I would look at cleaning the valves the same way lawnboy users look at decarboning the exhaust port. It's just a requirement of the design.

 

[Squareground3691]

Ethanol really has nothing to do with it. And 800T is probaly one of the poorest choices you could use in a 4mix. It's higher in ash content than a FC or FD oil. In addition to mettalic detergents it also uses mettalic zinc based anti wear additives, which are not ccommonly ound in most air cooled two cycle oils. In addition it has a high end point because it's designed for high tress motors. A low stress, low temp 4 stroke is not the best match for this oil.

Motul makes different oils for water and air cooled 2T applications , mine it for air applications,

 

[bwalker]

Ethanol doesn’t gum up carburetors and destroy their diaphragms , ? Interesting that 700 will be going on 7 years at end of this year , haven’t done anything to it , been flawless from the time I purchased it , used the same oil for over a decade ,

The issue we are talking about are related to the valves. Ethanol doesn't play into this at all.
Of course Ethanol is garbage and very hard on carbs, rubber, plastic, aluminum, brass, etc.

 

[WI_Hedgehog]

It doesn't really work like that. Many marine oils can pass FB, yet should never be used in air cooled equipment.

Would you explain that, I'm not understanding.

The JASO TWO CYCLE GASOLINE ENGINE OIL PERFORMANCE CLASSIFICATION document mentions 2-cycle motorcycle engines, and the testing is done on:
8.4 Supply of Test Engines and Parts
(a) Yamaha ET-1 engine
(b) RedMax Engine blower (EBZ6500) engine

 

[bwalker]

Motul makes different oils for water and air cooled 2T applications , mine it for air applications,

Yournis made for GP bikes in the like, but your right they do make a variety of oils. I haven't looked at their line in awhile, but 710 would be a better choice.

 

[Squareground3691]

The issue we are talking about are related to the valves. Ethanol doesn't play into this at all.
Of course Ethanol is garbage and very hard on carbs, rubber, plastic, aluminum, brass, etc.

Going on 7 years of flawless running , I think that say something with what being used ,

 

[bwalker]

Would you explain that, I'm not understanding.

The JASO TWO CYCLE GASOLINE ENGINE OIL PERFORMANCE CLASSIFICATION document mentions 2-cycle motorcycle engines, and the testing is done on:
8.4 Supply of Test Engines and Parts
(a) Yamaha ET-1 engine
(b) RedMax Engine blower (EBZ6500) engine

What exactly are you not understanding?

 

[bwalker]

Going on 7 years of flawless running , I think that say something with what being used ,

How many hours are on it? Oil related issues are seldom acute and almost always chronic in nature.

 

[Squareground3691]

How many hours are on it? Oil related issues are seldom acute and almost always chronic in nature.

Used weekly, obviously not in the winter months, BR800 the same,

 

[Squareground3691]

How many hours are on it? Oil related issues are seldom acute and almost always chronic in nature.

Facts are in the performance over that period of time , there’s nothing more to say ,

 

[WI_Hedgehog]

As far as I'm aware 2-Stroke FD oils can be used in place of FB oils.

3.2 Basic Concept of the Performance Classification

The performance level of 2-cycle oils is classified into three grades, FB, FC and FD, according to the test results based on the above-mentioned four JASO 2-cycle oil test methods. These are defined as FB, FC, FD from lowest to highest performance. The FC grade is defined for low smoke 2-cycle oils superior to FB with regard to exhaust smoke and exhaust system blocking. FD grade is defined as improved version of FC in terms of detergency performance at high temperatures.​

It doesn't really work like that. Many marine oils can pass FB, yet should never be used in air cooled equipment.

Would you explain that, I'm not understanding.

The JASO TWO CYCLE GASOLINE ENGINE OIL PERFORMANCE CLASSIFICATION document mentions 2-cycle motorcycle engines, and the testing is done on:
8.4 Supply of Test Engines and Parts
(a) Yamaha ET-1 engine
(b) RedMax Engine blower (EBZ6500) engine

What exactly are you not understanding?

I'm not understanding your point because to me what you're saying doesn't appear to correlate with the intentions of the JASO 2-cycle specifications nor the question about STIHL Ultra oil in @SteveSr's original post. Perhaps you're making a specific point about "marine oils" that's been a problem for others in other threads, but without more information I'm not seeing how it applies to this thread and would like to know what information I'm unaware of so I can understand your insight and benefit from your experience.

 

[bwalker]

Facts are in the performance over that period of time , there’s nothing more to say ,

Give it time.

 

[bwalker]

I'm not understanding your point because to me what you're saying doesn't appear to correlate with the intentions of the JASO 2-cycle specifications nor the question about STIHL Ultra oil in @SteveSr's original post. Perhaps you're making a specific point about "marine oils" that's been a problem for others in other threads, but without more information I'm not seeing how it applies to this thread and would like to know what information I'm unaware of so I can understand your insight and benefit from your experience.

I think what I wrote is quite clear. Marine oils are ashless oils, Ultra is an ashless oil. Stihl formulated Uktra like they did for the same reason marine oils are formulated like they are. To reduce ash buildup.
In addition FB oils are not all ashless. The low ash FB oils are better for a air cooled two stroke, but obviously not as good as FC or FD. FC and FD can not be met with ashless oils.
So no, FC or FD oils can not always be used in place of FB oils.

 

[Squareground3691]

Give it time.

Another decade,?

 

[bwalker]

Another decade,?

Maybe, maybe not.
Oil issues are seldom acute and often chronic.

 

[Squareground3691]

Give it time.

It’s already paid for itself , a few times over still going strong as when I bought it.

 

[Lionsfan]

So is the solution to not get a 4mix engine?

Get a legit 4 stroke, or a legit 2 stroke, but don't try and combine them?

If you can avoid it, that is the answer.