I`ve run loads of petrol power stuff on a 40:1 (unleaded and any old two stroke oil) mix in the past and it`s been fine, just got a Stihl hs80 and it don`t seem to like it. Been told got to run it on Stihl oil, but can that really be right ? A 2 stroke engine is a two stroke engine surely? Comments please.

there are hundreds off different grades off oil
different viscositys different burning point different penetrating different stickynes ect

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we are all ------------------still learning

Is it a very new sthil? All of my 2 stroke garden power tools (2 strimmers / brush cutters, 2 chainsaws and hedge cutter) run on 20:1 or either 25:1 so I use a mix somewhere in between for everything but I hear newer high quality ones run on a weaker mix.
If it puts out a bit of blue smoke especially being used hard its about right. A lot and its too much, little or none and its too little. Again newer, high quality tools probably smoke less.
What are the symptoms of it 'not liking it'?

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Mike

Mike,
Not sure what the problem is with it but, when I refueled aeroplanes, the piston engine planes with a petrol engine would only run on either Avgas 100L (green in colour) or 100LL (blue in colour) and would normally have fallen out of the sky using the old 4* or the newer Unleaded 95RON. So if the manufacturers say to use a certain oil, they are not really doing it just to make a profit, considering how little of the stuff you will use.
Stick with the recommendations.

dave

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You can always tell a Yorkshireman,
But you cannot tell him much.

Thanks for this thread, I have just run out of two stroke mix and I wil make sure I buy the proper McCulloch oil that I have been using rather than the BnQ own brand inlight of the comments.

DWD

Hi Mike- symptoms of it not liking it are it wont start! It`s ex council, so could only be a year old but looks twenty! Seriously, looks about 5 or more years old. Ran fine with some fuel it came with, but when I put some of my mix in, it died and wont restart. Tipped some of the original stuff out to see the colour, and it stained the road black and didn`t dry away and leave no trace like my stuff does, just stayed there like car engine oil. I`m thinking Stihl oil really is different and maybe I should get some. Still find it hard to fathom that a 2 stroke engine can be manufactured to run on only one type of oil which is only one fourtieth of the make up of the mix, though. I`ve run Mcculloch, Tanaka and Challenge (sorry) on a 40:1 with no probs. Recently been told Husky`s have there own oil as well, and I`ve just bought a second hand 125r brushcutter. Oh shoot.

Never heard of it myself.
Always used just any old 2 stroke oil in 4 or 5 different motorbikes, a boat - OK I used marine 2 stroke but just any old make and too many garden machines to count. After I got rid of my boat I had 3/4 gallon of the marine 2 stroke oil left over (think the make is total). ALL the 2 stroke engines I had in the last 5 or 10 years have been run on a approx 25:1 mixture of this and standard unleadded petrol. All have run quite hapilly on it and are still running well. I do garden maintenance on and off and get through about 5 gallons of this mix a year the last few years. All the engines are still working well or were when another part of the machine failed.
But then I've never owned a sthil or a husky.
I see no reason why any brand of chainsaw or other 2 stroke garden machine should not work fine with any brand of 2 stroke oil though you may invalidate any warranty if they can prove you have used another make.
As to your symptoms I guarantee any 2 stroke engine will start and run with any make of 2 stroke oil, even no 2 stroke oil at all but of course it won't run for long. From the information given I have to wonder about the correct mix for that machine. That is the first thing I would check before going any further. If it is meant to run on a 25:1 mix and you run it on a 40:1 mix that can cartainly cause problems. If it ran hot or semi seized a metal filing could be shorting out the plug.
You need to be doing basic checks - is it sparking? Is the plug getting wet whe you try to start it?

PS. I just checked. This is what it says on the stihl website for your hedgecutter:

2 Stroke Fuel Mixing

When using STIHL 2 stroke lubricant:

Mix at 50:1 (20mls oil per 1 litre fuel)

When using any other brand of air cooled 2 stroke:

Mix at 25:1 (40mls oil per 1 litre fuel)

So you can use ANY make but check your ratios.

Also note that the more oil you put in the petrol the less petrol is in it so the leaner (and hence potentially hotter) the engine runs. If the fuel air mix is correct for a 40:1 mix you would expect to have to richen up the mix by tweeking the adjustment screws on the carburettor when you chasnge to 25:1. Just an 1/8 of a turn or less I would expect. Again though it would run without, just it would run lean and this could do damage.

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Mike

Thanks for the info Mike- very helpful. Simply because I had been given some free, I drained my mix out and filled up with Stihl at 50:1, and it started right away. Looks like my mix was not rich enough or summat. In light of your comments, I wont necessarily stick to Stihl, but I`ll make sure I run it on 25:1 if I`m using any old oil. It seems, luckily, I didn`t bu**er the engine up. Cheers all.