[tonel]

Hello, hope I can get some help with a question about a 2-stroke strimmer (I know next to nothing about engines/mechanical stuff unfortunately). I've had it for a while and it seems to work well but it does smoke a lot and after use it seeps quite a lot of black oil from the exhaust. The manual for it states to use a 40:1 mix (I have a marked mixing bottle so hoping the mix is about right).

I've read up a bit and it sounds like it might be running too rich, I know it's better to be too rich than too lean but am wondering if maybe trying a 50:1 mix might work - or is that a really bad idea? (don't want to go wrecking it). I've heard that 2-strokes are quite smoky but this one seems to smoke a lot and a lot of black liquid seems to leak from the exhaust after use. If anyone could give any advice I'd be really grateful!

[arugula]

Assuming the machine is running properly, it should be blueish smoke you see..  Have you checked it isn't leaking gearbox oil? One other thing you could try, if it seems rich you could try a 45:1 mix. Its a less drastic change than 50:1 would be..

[Kleftiwallah]

Does it increase in revs as soon as you twist open the throttle?

Does it tick over / idle steadily when you take your hand off the throttle?     Cheers,     Tony.

[smud6ie]

What is the make of strimmer,how old and if bought new has it always smoked?Try running for a few minutes with no air filter but not cutting  to see if it burns cleaner.
smud6ie

[tonel]

It's a McCulloch, was bought new, has been used it a few times. It revs up fine when pressing the throttle trigger, initially it wouldn't idle without cutting out but adjusted the idle screw, seems to be okay now. Would be tricky to start at first, wouldn't start unless choke was off, even when cold - last few times I've used it it'd start on half choke. Don't think I've ever managed to start it with full choke as mentioned in the manual..

Just worried mainly by the amount of black oil coming out of the exhaust. Maybe it's normal..as I said, I don't know much about stuff like this

[Gwiz]

If you're using the mixing bottle correctly, there is little chance that the mixture is going to be incorrect. Don't be tempted to change from what the manual tells you to use.
Nowadays, there are differences in different two stroke oils, Some are meant for marine use where the engines are usually water-cooled and so are designed to run cooler than an air cooled engine. Some oils are fully synthetic, others are semi synthetic and a lot are still fully mineral oil. All burn differently.
I think your machines exhaust is always going to be oily, most of the McCulloch machines I see in the workshop usually have the same drippy exhaust.
This is a common thing in the "Budget brands so don't worry too much about it. Just don't put it down on the back seat of your car without wrapping the engine in plastic (after it's cooled down, of course!)

[tonel]

Thanks for all the advice everyone, I won't risk messing with the fuel mix, would rather it be a bit oily & smoky than damage it.

No worries about the car seat either, I can't drive and know better to risk the wrath of my wife if I mess up her car

[teamspotty]

Blue smoke indicates that its burning a lot of oil...

[arugula]

Blue smoke indicates that its burning a lot of oil...

Two strokes emit blue smoke as they burn the oil that is added to the fuel by design.

[Gwiz]

Blue smoke indicates that its burning a lot of oil...

Two strokes emit blue smoke as they burn the oil that is added to the fuel by design.

Like wot she said.

[teamspotty]

Blue smoke indicates that its burning a lot of oil...

Two strokes emit blue smoke as they burn the oil that is added to the fuel by design.

Like wot she said.

Yep, it should burn oil, but the smoke really shouldn't be noticeably blue...

[smud6ie]

We run a dozen Stihl 2T's and if there's any blue smoke,some one has over dosed the oil by some way or its time to clean the air filter.
smud6ie

[Gwiz]

I wasn't going to reply, but it really does depend on what type of oil you use. We run different manufacturers machines. Many of them have different oil ratios. Obviously, the ones that have a higher oil mix tend to smoke more than on, say, a Stihl machine running on fully synthetic oil at 50:1 mix.
The cheaper types of engines that haven't had the same amount of product development or engineering tolerances all tend to be smokey. This is something I have observed from dealing in the horticultural machinery trade for the last 27 years.

[smud6ie]

 Ahh how I miss the days of carrying around a Danarm DD8fMk3,1/2 1 pint of oil to a gallon of petrol and so much smoke it was hard to see your mate cutting down the next tree and trusting him   it wasn't  going to fall on you!! 
smud6ie

[Gwiz]

Yeah, but YOU personally never suffered from Greenfly, did you?