How a'm I getting my 2 stroke mix so wrong?

[dannythemanny]

I have a new hedge trimmer and it says ratio 40:1. I mixed it up using the bottle provided but the hedge trimmer gets too hot, cuts out and smokes. Made a fresh mix and had another go but the same thing happened again! I can't see how I have the ratio so wrong. How accurate do you have to get the ratio? Because its as close as I'm ever going to get it, looks fine by my eye but obviously Ive got it badly wrong. Any ideas how to fix this or any tips to make a correct mix.
thank you

 

[Bobby Kirbos]

Welcome to the board Danny.
In reality, close enough is close enough. If you used the 40:1 pre-measured bottle, you're at 40:1 (or at least close enough to call it 40:1). Guys run 50:1 in saws, WAY harder than any hedge trimmer would ever be run, and don't have issues. Being that it is a new trimmer, I suspect that it is tuned lean.

Hit up youtube for videos on how to properly tune a 2 stroke engine. To meet EPA emission regulations, many manufacturers tune their equipment lean.

Sorry if this is very basic... not knowing your level of knowledge on this stuff
In short.... mixture is the ratio of air to fuel as produced by the carburator. A rich mixture means more fuel. A lean mixture, not enough fuel. How does a lean mixture equate to running hot? In its transition from a liquid to a vapor, the evaporating fuel absorbs heat from engine components.

 

[ammoaddict]

How many ounces of oil to how much gas are you using?

Sent from my moto g(7) power using Tapatalk

 

[dannythemanny]

Not sure about ounces sorry. Just using the bottle provided filling the petrol part up 1/2 liter mark and then filling the oil part to the 1/2 way mark on the 40:1 gauge. You'd think it was fool proof
I'll have a look how to tune it or maybe try with a little less oil.
Thank you for the help

 

[Philbert]

'40:1' = 128 ounces (1 U.S. gallon) of gas: 3.2 ounces of mix oil, right?

Or, 1,000 ml (1 Liter) : 25 ml.

Not sure what your gauges look like - a photo of them might help.

Philbert

 

[The Lorax]

Not sure about ounces sorry. Just using the bottle provided filling the petrol part up 1/2 liter mark and then filling the oil part to the 1/2 way mark on the 40:1 gauge. You'd think it was fool proof
I'll have a look how to tune it or maybe try with a little less oil.
Thank you for the help

Is it a 1 litre bottle?
For 40:1 you need 40 litres petrol to 1 litre of oil, 20 litres of petrol to 500ml oil, 10 litres petrol to 250ml oil, 5 litres petrol 125ml oil 1 litre to 25ml oil.
I would mix 1 litre minimum as less than that the ratios get less precise as you are dealing with surface tension etc.

 

[Fatherwheels]

Either your mix is wrong, or your mix is right and your engine is not right,
either way, engine running too HOT to the extent it cuts out more than likely means
the piston is gone, and likely cylinder damage too.
Take it back to the dealer you bought it from and explain how it ran from new.
Your mix may be correct, but if the engine is that hot it won’t run, then something is wrong.

Put up a picture of the measuring bottle showing the scale, some bottles have scales on both sides
that show different numbers for different ratios.

What is the model of trimmer you have.

 

[mexicanyella]

This seems like an interesting approach to starting an oil thread.

 

[jp233]

take the guesswork out of mixing. There are little bottles that the marine community use, cheap on Amazon.

But if you want to mix small quantities and especially want to be able to accurately do multiple ratios, go get an Accu-Mix jug and never look back.

https://www.accu-products.com/accu-products-specialties/accu-mix-fuel-jug/prod_3016.html
post, some more stuff here: https://www.arboristsite.com/community/threads/ideal-fuel-mix.343984/page-2#post-7327229

 

[holeycow]

Likely you have a phone. Likely it has a calculator. Measure your gas reasonably close. Enter that volume in your calculator. Divide by 40. That is your oil amount. Close enough.

as suggested, your little motor is probably stupid lean, mixed fuel to air ratio.

anyway, the mix doesn't have to be perfect at all. Close is fine. Every oil is different and has an effect on how things run. I try to pick an oil that burns clean with as much oil as possible in the mix, down to as close to 30:1 as I can get it, if it's a racing two stroke bike that is. I don't sweat the same detail in my chainsaws, trimmer, etc, which I run mostly near 40:1.

i doubt the problem is your mix.

 

[cuinrearview]

Seems like an easy answer right here, especially with a tool that's seldom used.

 

[cuinrearview]

Or maybe this if your location is accurate.
https://www.caerfagu.co.uk/garden-machinery/aspen-and-stihl-fuel/

 

[Philbert]

Seems like an easy answer right here, especially with a tool that's seldom used.

Good point. Especially, to see if the tool runs right using the pre-mix stuff.

Philbert

 

[holeycow]

Yuk!, but ya!

 

[dannythemanny]

The is the mixing bottle I use. The oil says on it semi synthetic don't know if that makes a difference?
I may get some premix stuff.
Thanks for the help

 

[MacAttack]

I have a new hedge trimmer and it says ratio 40:1. I mixed it up using the bottle provided but the hedge trimmer gets too hot, cuts out and smokes. Made a fresh mix and had another go but the same thing happened again! I can't see how I have the ratio so wrong. How accurate do you have to get the ratio? Because its as close as I'm ever going to get it, looks fine by my eye but obviously Ive got it badly wrong. Any ideas how to fix this or any tips to make a correct mix.
thank you

Usually you get a little bottle that you just dump into a gallon of gas, when you buy a new hedge trimmer, leaf blower, etc. Is that what you did?

 

[Deleted member 117362]

Just straight gas it. Problem solved. Use clippers.

 

[Huskybill]

When not using the non ethanol pre mix 50:1 cans I buy the two stroke oil in the little bottles that mixes 2.5 gallons and use 2.3 gallons at the pump.
Can never go wrong.

 

[cuinrearview]

Can never go wrong.

This, it made me chuckle...

 

[Huskybill]

This, it made me chuckle...

Mixing two stroke to the same bottle of oil to 2.3 gallons of gas is fool proof. I always mix the two stroke in the morning when I’m fresh, my mind is clear. With saws that cost $1,000 I don’t make mistakes I can’t afford too. I take it very serious.

We have a big job this fall coming up. Probable mixing 5+ gallons of mix or more.