Thread: Brush cutter - How to run in engine?

I purchased my old Shingu straight shaft w/s many years ago and put it straight to work on my then lawn mowing round. Its still going strong and only played up when the spark plug was dying or the air filter was choked up with dust. One thing I did was to remove the grease cap from the spool head and fit a grease nipple to regularly grease it.

All I used was 25:1 mix, which in those days was available straight from the BP 2stroke pump. Now I buy 2 small oil containers and mix it with 10litres of U/L petrol in a plastic jerry can that comes with its own pouring spout.

If the manual says 25:1 for normal use, stick with the 25:1 but don't load the machine too heavily for the first hour or so of running.

Some machines will specify 50:1 with specific branded oils, or 25:1 with other oils. (Sthil is one). They generally reccommend to run at 25:1 for the first few litres.

You should mix fuel in smallish batches that you can use within 3 months, and you need 40ml of oil for every litre of unleaded petrol for 25:1.

If possible mix in a new clean can by accurately measuring oil and decanting, then adding unleaded at the servo using their metering. If mixing a 5 litre can, you can generally flow the fuel onto the oil fast enough for the first 2-3 litres to mix all oil into the fuel, so a good shake after replacing the pump and capping the can will give a good initial mix.

If you mix smaller quantities, say 1 litre, I normally add about half the petrol to the oil, stop, cap the container and shake vigorously, then top up with the balance of the petrol to ensure that the oil is fully disolved in the mix.

Paper coffee machine filters in the funnel bowl when filling help to filter out dirt and other rubbish. The most likely problems with a well built machine running the correct fuel oil mix will be contaminants clogging the carby passages.

I would agree with keeping up grease in the gearbox, either by regularly unscrewing the plug or by adding a nipple.

Run in a 2 stroke... whats that?

I would run 50:1 for the first tank and 25:1 after that.

You can only really gunk up the plug with a tankful but its good insurance

Er, Daz, you're suggesting a "leaner" oil mix there for the first tank.

Probably mean the other way round, ie. more oil in the first tankful.

2 Stroke power tool.... Run it like you stole it

Any running in it might need should be done at the revs and load you would normally use it at. The carb may need to be adjusted after the engine frees up a bit, maybe 5 or 6 tanks of gas, they are usually set a bit rich from the factory. But otherwise, fire it up and start wacking.

Cheers

Ian

Run it like you stole it... good point!

I haven't heard of "running in" a 2 stroke engine.

If there is no mention of running in, in the owners manual, like the others said, run it like you stole it!!!!

I recently purchased a Stihl 2 stroke blower (a top machine) and there was no mention of running it in, in the book.

I initially chose to run it at medium revs for short 5-10min sessions until its first service. Then it was full on.