40:1 to rich?

[Cstratton]

Most of what you're seeing isn't carbon, it's discoloration from heat, the piston crown also had some erosion from heat.

I guess I should have studied the picture better before I replied. I definately agree on the 100:1.

 

[Chopper G]

In case DOLMAR High Performance two-stroke engine oil is not
available, it is recommended to use a mixture ratio of 50:1 with
other synthetic two-stroke engine oils, as otherwise optimum
operation of the engine cannot be guaranteed.
The correct mixture ratio: 50:1 when using DOLMAR High Performance two-stroke engine oil

It is not wise to add more engine oil than specified to ensure
safe operation. This will only result in a higher production of
combus-tion residues which will pollute the environment
and clog the exhaust channel in the cylinder as well as
the muffler. In addition, fuel consumption will rise and
performance will decrease.

Meh, WTF do the cats at Dolmar know? ; )

 

[tdi-rick]

And trimmers are even lower than that...so thank you for proving my point....

and my point was more to the effect that most trimmers only run in the 9,000 rpm no load...so maybe thats not hot enough to burn off the extra oil...

More than likely not enough heat/load to activate and burn the EP/AW additives that are present.

If it was a castor blend, I'd put my money on the castor not being consumed so what you said in your last sentence would be correct.

 

[tdi-rick]

To lubricate the engine, use a synthetic oil for two-stroke aircooled
engines (quality grade: JASO FC or ISO-L-EGD), which
has to be added to the fuel. The engine has been designed for
use of DOLMAR High Performance two-stroke engine oil and a
mixture ratio of ONLY 50:1 to protect the environment.
[snip]

From the PS64/73/7900 manual.

In case Makita (Dolmar) high-performance two-stroke engine oil is not available, it is urgently recommended to use a mixture ratio of 40:1 with other two stroke engine oils, as otherwise optimum operation of the engine cannot be guaranteed.

This is stated again in the next paragraph in bold, as well as a graphic showing 50:1 and 40:1 in the next column.

In Europe Dolmar/Makita sell a full syn oil that's recommended to be used at 100:1, just like Amsoil Sabre.
Not sure I could do that.

 

[birddogtg]

Meh, WTF do the cats at Dolmar know? ; )

They don't know anymore then these guys
Two-stroke oil
• For best results and performance use HUSQVARNA
two-stroke engine oil, which is specially formulated for
our air-cooled two stroke-engines.
• Never use two-stroke oil intended for water-cooled
engines, sometimes referred to as outboard oil (rated
TCW).
• Never use oil intended for four-stroke engines.
Mixing ratio
1:50 (2%) for all engines. STIHL recommends a mix of 50:1 high-quality (89 octane minimum) regular unleaded gasoline to STIHL engine oil. This same mix ratio should be used during break-in.

 

[MS460WOODCHUCK]

50,40,50,100,32,50,100,40,40,50+1oz I knew I should've never asked.

 

[Chopper G]

In Europe Dolmar/Makita sell a full syn oil that's recommended to be used at 100:1, just like Amsoil Sabre.
Not sure I could do that.

Bam:

I could not go 100:1 without knowing a lot more about the product.