Stihl 500i

[Magnus]

I doubt oil is the larger culprit in this drama. Fuels properties and composition is likely the larger factor combined with the manufacturing, recycling etc
Emissions is not so much whats burnt, rather whats not and that is a bigger problem in a two stroke high reving engine.
There is oils that are very good but the temps variations are no easy nut to crack.
In most other engines the temp is easily controlled with cooling systems that let it heat up fast and stay within a short specific temp range.
Aircooled temp range is much wider and harder to control in a saw for example.

The principals behind the engine types is pretty fixed, like laws of nature.
A two stroke flushed engine has few moving parts and low weight for the power it produce.

 

[FireFighterZero]

Maybe they turn it into two stroke oil and sell it?

 

[cory]

Another interesting response, Magnus. I appreciate your perspective.

 

[Magnus]

You are joking, but some is turned in to two stroke, some hydraulic, transmission or other oils.
Recycled oils is very common. We called it "Washed oils" earlier, now its pretty much standard.

 

[Magnus]

Another interesting response, Magnus. I appreciate your perspective.

Thanks.
Being in bed a lot reading, some testing and trying give a awfully lot of perspective...

 

[kevin bingham]

Brutal!

Yeah I like my stock saws just fine. They cut like a mofo and they're plenty loud as is

Yeah I'm with this sentiment as well. A few seconds shaved off of the cut time doesn't seem worth the noise at all.

 

[Mick!]

The 4mix engines don’t run oil in the sump, unless I’m mistaken?

 

[stig]

You are not mistaken.
The lube in the 2 stroke mix makes it redundant.

Magnus, it is good to have somebody onboard who actually knows what they are talking about, I always appreciate your input in these discussions.

 

[Magnus]

Thanks, Stig.

Mick.
There is two types of four strokes in hand held stuff. Those that is called four mix and have oil in fuel are more common and are used mostly by Stihl at this point in time
Others have it as well, but don't sell as many. The consumer grade four stroke saws from east is also this type.
Then there is pure four stroke engines with sump pump and hole kit! Most common is a engine built by Honda that Stiga and others had/have.

Valve systems vary a bit as well

 

[FireFighterZero]

You are joking, but some is turned in to two stroke, some hydraulic, transmission or other oils.
Recycled oils is very common. We called it "Washed oils" earlier, now its pretty much standard.

I wasn't joking.

 

[Mick!]

Ok thanks Magnus, how does having sump oil in a hand held device react to being used upside down etc?

 

[Bermy]

Mick, the 4 mix Stihl tools all use mixed petrol and don't have sumps, I have the pole pruner and a kombi tool. Reliable and a bit more quiet than 2 stroke.

 

[Magnus]

Ok thanks Magnus, how does having sump oil in a hand held device react to being used upside down etc?

Not well at all, but in some machines you only operate in one position. Trimmers, back pack blowers as example.

 

[Mick!]

Mick, the 4 mix Stihl tools all use mixed petrol and don't have sumps, I have the pole pruner and a kombi tool. Reliable and a bit more quiet than 2 stroke.

I know Bermy, go back a couple of pages.

 

[SeanKroll]

Not well at all, but in some machines you only operate in one position. Trimmers, back pack blowers as example.

Largely, the backpack blower is used right-side up, but don't necessarily stay in that position. Imagine if your blower couldn't fall over because of the oil reservoir. You'd have to drain it down, at the least, I'd think.

I operate my Kombi in all positions.

My Kombi 4-mix, or whatever its called, has been used a lot, over about 10 years. I checked the valve clearance. Still tight. Landscapers who run blows for hours a day will have a lot higher run time. I'm guessing the video diy for valve tightening was on a very, very high hour machine. Super easy to check the valves. No replaceable gasket.

 

[Merle Nelson]

"I am crazy, I know that.. But this environmental stuff is way worse than most rational thinking...[/QUOTE]

Always good to know where one is at.
Even so I always appreciate your informed posts on these topics too Magnus.

 

[Bermy]

Landscapers in Bermuda are wedded to their leaf blowers, sometime I wish the four mix ones would blow up.
Gotcha Mick, not trying to tech egg sucking, sorry!

 

[Magnus]

I am not too familiar with the blowers, but I know there is. I don't see why it could not be tilted and upright again and still run. But run it on its side I doubt would be a bright idea. Most running backpack blower tend to stand, atleast those I have seen running them And the 20min a year I run mine...
The trimmers I see here once in a while. Some from Stiga, some from Honda.
They work ok. Its a good engine for this purpose.

 

[SeanKroll]

I hear that backpack blowers used to wind up and whine a lot more, now more bass. The Capital Campus uses them a lot. Someone who worked there, mentioned it to me (the guy who buys blowers).

 

[Stumpshot]

Sometimes I sling our Stihl backpack blower with just a single strap, so it is running at a 45 degree angle. Granted, that is just for a quick driveway blow-off or the like, usually under 5 minutes. Extended blow-offs, such as when we drop a crispy dead cottonwood in the street and it shatters into exactly 15.4 million pieces, I for sure run upright with both shoulder straps.

 

[Magnus]

I don't know if it would work, but I suspect it would up to 45 degrees. A quick look in manual would perhaps tell for sure.

There is different sizes on blowers. Largest handheld is likely just as good as the smaller back pack.
But if I was to choose tool for a work that takes some time I rather have back pack blower on than carry the hand held.
There is a lot of hand held sold to homeowners. Back packers are mostly for pro's that run a bit more and longer.
There is quite a bit difference in the huff and puff in them between models so a try before purchase is not bad.

 

[Bermy]

Backpack blowers are still 4 mix...I hate them, from hearing and watching landscapers use them for hrs to blow every conceivable loose speck of grass or leaf off stupid over pristine over priced lawns and fancy gardens.

Literally, I went to find out what the hell one guy was doing one day on a property a few over from my Mr. Moneybags job...he must have been blowing for an hour. It was the time of year the oleanders drop their flowers...poor flowers, no rest for bright pink and red petals besmirching the green sward

 

[Magnus]

Its not good to say "They are still 4-Mix".
Makes it a vage, inaccurate and confusing as there are blowers with all types, regular two strokes, strato two strokes, 4-strokes, 4mix...

Mot so easy to talk about these things anymore as its not many that is the same.

 

[Bermy]

To clarify, Stihl blowers are mix, ya know I thought about it for a while and I can't say for sure if they are 4 mix or not, but they are mix...husky ones run on mix gas too, not sure if they are 2 or 4 stroke, I just know that after 20 mins I could bash someone over the head with one to make them shut up, I intensely dislike the constant droning.

 

[Dave Shepard]

The BR700 is 4mix. They'll run well over an hour on a tank. I run them all day long when I'm helping a friend with fall cleanups. They blow as well as an 8 hp push blower. I don't like the sound, either, but it's better than a push blower.