STIGA SB 320D Brush Cutter: Synthetic Oil Recommendations & 2.5% Fuel-Oil Mixture Preparation

Hello,
I'm about to start a new brush cutter. I have a few questions as I am a layman.
1. It is stated in the manual to use synthetic oil of the highest quality for two-stroke engines. What do you recommend?

2. It is also written that using these oils allows to obtain a mixture of 2.5% where 1 part of oil is 40 parts of gasoline.
e.g.
1l of gasoline - 0.025l of oil (table)
5l of gasoline - 0.125l of oil (table)
And to prepare the mixture:
a) Pour about half the amount of gasoline into the approved canister
b) add all the oil according to the table
c) refill the remaining gasoline
d) Close the stopper and shake

I understand that as I marked here?


These fuel and oil divisions (40: 1) are thus shifted by 0.4 cm. So if you pour 500 ml of fuel, the 0.4 cm difference is oil, right? and I have to mix it and pour it into the tank?

Ps. Do you pour a 1:50 mixture at the beginning when running in the engine? Apparently it looks a bit different than in the manual during break-in ... What do I need to know about the break-in and after what period of time can I consider the engine run-in?

I use Stihl HP 100ml for 5 canisters (1:50) 8 years without stuttering I only replace the air filter but my scythe is Stihl.

jajuń wrote:

Hello,
I'm about to start a new brush cutter. I have a few questions as I am a layman.
1. It is stated in the manual to use synthetic oil of the highest quality for two-stroke engines. What do you recommend?

2. It is also written that using these oils allows to obtain a mixture of 2.5% where 1 part of oil is 40 parts of gasoline.
e.g.
1l of gasoline - 0.025l of oil (table)
5l of gasoline - 0.125l of oil (table)
And to prepare the mixture:
a) Pour about half the amount of gasoline into the approved canister
b) add all the oil according to the table
c) refill the remaining gasoline
d) Close the stopper and shake

I understand that as I marked here?


These fuel and oil divisions (40: 1) are thus shifted by 0.4 cm. So if you pour 500 ml of fuel, the 0.4 cm difference is oil, right? and I have to mix it and pour it into the tank?

Ps. Do you pour a 1:50 mixture at the beginning when running in the engine? Apparently it looks a bit different than in the manual during break-in ... What do I need to know about the break-in and after what period of time can I consider the engine run-in?

As for the proportion: 1:50 is a mixture less than 1:40! 1 is oil, 40 is fuel. If you take 1 measure of oil and 50 measures of fuel instead of 40, you have more fuel for the same amount of oil, which means worse lubrication and the risk of seizure. If you want to make a richer mixture at the beginning - do 1:25 (100ml of oil for 2.5 liters of fuel).

As for the time of arrival, I recommend getting through the first 5 fuel tanks. It is best to leave the scythe at idle for the first time and let it burn the entire tank in this way. The rest of the lapping is mowing low grass. It is crucial not to burden the scythe during this period. After the break-in period, we go back to the manufacturer's recommendations (1:40 in your case) because too much oil will cause carbon deposits.

Of course, the best oil would be full synthetic. I use the American semi-synthetic ALCO oil with a blue color (it stains the fuel nicely - you will never make a mistake and you will not add pure fuel). I have never had a problem with this oil. I know that ALCO also offers a full synthetic, but the service technician recommended this one and I'm really happy.