Strimmer Mix Query

Jjjjjjjjbarry

Hi,

I've just bought a new strimmer. It came with a bottle that's pretty easy.. petrol to here, oil to here.

However it says it needs 40/1 oil so I'm a bit confused. I bought some two stroke oil but it doesn't mention ratio on the bottle. I know you can buy oil that says 40/1, 50/1, 32/1 etc as I bought some before for my car. Have I bought the wrong oil or is the 40/1 the ratio of petrol to oil - which the mixing bottle markers will take care of.

Very confusing! 😀

T-Maxx

Nevermind what the oil says, go with what the machine's manufacturer says.

coillsaille

The strimmer is a two stroke engine, which means it needs two stroke oil to be mixed with the petrol. As long as it's two stroke oil then it doesn't matter what else is written on the bottle.

There isn't really much difference in practical terms between adding the oil at ratios of 40:1 or 50:1. If in doubt go for the 40:1, too much two stroke oil added is better than not enough. Too much means a bit of smoke from the engine but no harm in that, not enough could mean a seized engine that's fecked.

I had a strimmer before that specified 50:1 in the manual but had 40:1 stamped on the fuel cap!

The Continental Op

Always used to be 30:1 but really the whole story is down to quality. Quality of the machining of the engine parts and quality of the oil. I'd have no hesitation saying any modern 2 stroke can be run at 50:1 with good quality oil. Anything with a well know brand name should be decent quality oil, Husqvarna, Stihl, Oregon etc.

Quantity wise 50:1 is 5 liters of fuel and 100ml of oil. If you are happier to use 40:1 the simplest way is to start with 4 liters of fuel in the can and still add 100ml of oil. So its accurate I fill the fuel can with the amount of fuel required at the petrol station.

I've been running a cheap Trojen strimmer at 50:1 for a couple of years and its fine. Instructions say 30:1 and 40:1 (typical chinese) but 50:1 and it runs really well.

The big issue with 30:1 is that with smaller 2 stroke engines (under 30cc but also affects bigger ones) is that you get a build up of sticky carbon gunk in the exhaust which can block off the port completely.

I suspect chinese think everyone is a cheap as them so because they think you could be using any old oil you have rather than 2 stroke oil they say you need more oil than strictly necessary.

blackbox

The first post suggests that the strimmer has a dedicated oil filler cap. I've never seen one with that.

The user manual should clarify.

The Continental Op

https://www.boards.ie/discussion/comment/119440533#Comment_119440533

Think what the OP means is something like this cheap chinese 2 stroke mixing bottle.

https://www.amazon.co.uk/DAZZLEEX-Mixing-Bottle-Container-Chainsaw/dp/B09Y1GJFC4/

Over the years I've had maybe half a dozen of those stupid things and I recently had a tidy up and threw most of them away. I'd never use one and I don't recommend anyone else uses one. Mixing just a liter or less of fuel increases the possibility of inaccurate mixing. I've seen tank mixing fill the fuel tank on the engine up then add oil thats even worse.

One other thing I'd also recommend to anyone using 2 stroke engines. Use a 2 stroke oil with a dye in it so its easy to spot that there is oil in the mix. Its easy to buy fuel get side tracked do another job then come back a few days later and just use the fuel you have. Did you put any oil in it? The dye at least lets you know. Working with a gang of lads the 2 stroke can had 2 stroke petrol in it as far as the lads were concerned. If one person was a bit slow putting the oil in another could use the fuel without any oil. I use to get lads to check the fuel had the red, blue or green colour when using it if not to ask!