# Forum Home Renovation Tools & Products  Whipper snippers - four stroke

## ErrolFlynn

Am in the market for a new whipper snipper.  And blow me down, did I read that right: 4 stroke engines.  It has always been my assumption that 2 stroke was the design of choice which allowed the engine to run at most angles off level; no sump.  Has anyone used a 4 stroke unit?  What has your experience been (starting, maintenance, reliability, issues wiht oil, etc)?

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## johnc

> Am in the market for a new whipper snipper.  And blow me down, did I read that right: 4 stroke engines.  It has always been my assumption that 2 stroke was the design of choice which allowed the engine to run at most angles off level; no sump.  Has anyone used a 4 stroke unit?  What has your experience been (starting, maintenance, reliability, issues wiht oil, etc)?

  I use a Stihl four stroke pole saw, there is no sump and you mix oil in with the fuel, I think what you are looking at is the same.

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## ringtail

> I use a Stihl four stroke pole saw, there is no sump and you mix oil in with the fuel, I think what you are looking at is the same.

  So that will be a two stroke then  :Tongue:

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## ErrolFlynn

It was the Honda that I saw it with, no doubt other makes have them too. http://powerequipment.honda.com.au/D...425_Bent_Shaft

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## ringtail

I don't like 4 stroke whipper snippers. I also don't like the standard mantra that all the dealers pull out - no more mixing messy fuel and oil etc... It's just rubbish. There is one golden rule with 2 strokes and that is fresh fuel. mix a little bit at a time and they are perfect. 2 strokes crap all over 4 strokes for horsepower, simplicity, maintenance, purchase price and repair. And I'm talking whipper snippers / brushcutters/chainsaws here, not mowers. Have a look at any commercial mowing contractors and they will be using 2 stroke snippers. Mostly Shindawa but a lot of stihl and echo.

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## sol381

> So that will be a two stroke then

  reply of the week...

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## dmac

I have the little Honda four stroke whipper snipper. Absolutely love it, It's quite, easy to start and has ample power. 
It's now about 5 years old and has never missed a beat. Each Christmas it gets an oil change and air filter clean and that's it. 
Dave.

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## johnc

> So that will be a two stroke then

  Looks no different to a two stroke but Stihl HT131 is a genuine four stroke, it is all about valves I guess, not that I'm interested in how it works.

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## ringtail

Wow. Ok, did a bit of research and I take back my smartar##d comment. They are a oddball hybrid engine. Very interesting concept. How long have you had it johnc ? A few people complaining about the valves constantly going out of adjustment but that's about all the negative feedback on them.

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## Marc

> Am in the market for a new whipper snipper.  And blow me down, did I read that right: 4 stroke engines.  It has always been my assumption that 2 stroke was the design of choice which allowed the engine to run at most angles off level; no sump.  Has anyone used a 4 stroke unit?  What has your experience been (starting, maintenance, reliability, issues wiht oil, etc)?

  Straight shaft, handles, 2 stroke, Shindawa, Kawasaki, Stihl

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## METRIX

> Wow. Ok, did a bit of research and I take back my smartar##d comment. They are a oddball hybrid engine. Very interesting concept. How long have you had it johnc ? A few people complaining about the valves constantly going out of adjustment but that's about all the negative feedback on them.

  I never understood how the 4-MIX engines worked, here is a video, and I still don't understand it  :Biggrin:   https://www.youtube.com/watch?v=cAHq118pEgI

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## johnc

> Wow. Ok, did a bit of research and I take back my smartar##d comment. They are a oddball hybrid engine. Very interesting concept. How long have you had it johnc ? A few people complaining about the valves constantly going out of adjustment but that's about all the negative feedback on them.

  About 18 months, we have a couple of very large trees in the backyard which need an infrequent prune, it gets very little use between us a couple of neighbours and the odd friend. No different to operate than the two stroke version, apparently slightly less power, quieter, less air pollution. Bought it to replace a stolen two stroke I used to borrow and much safer than a chainsaw up a ladder  :Wink:  So far no trouble and starts and runs easily.

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## mudbrick

> I never understood how the 4-MIX engines worked, here is a video, and I still don't understand it   https://www.youtube.com/watch?v=cAHq118pEgI

  Just a single cylinder 4 stroke but instead of a sump and oil pump the air-fuel-oil mix passes over the rockers and sucked down into the 'Sump' before entering the cylinder and being ignited. The green stuff in the video is the fuel mix moving around.

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## Marc

The advantage of the 4 stroke is a better combustion due to the valves doing a good job of clearing burned gases. Also the 4 stroke can take higher compression because it uses fuel and not mix that auto ignites if the compression is too high. The 2 stroke relies on the fresh mix sweeping the burned gases and it's timing is a compromise due to the ports being in a fixed position so has an inbuilt inefficiency. The 4mix uses the valves to get a clearer combustion and a crankcase and head lubricated by the mix. The problem with the 4mix is that the 2 stroke oil mix is not enough to keep the valves in a good condition and they wear and need adjusting. The rate of oil mix that would keep the vlaves happy would make the motor smoke and the caffe latte ladies would run away in horror. 
Also the use of mix negates the use of higher compression.
There is no need to buy 4 stroke or 4mix in such bonsay sizes. This engines are a curiosity, the consequence of green culture, expensive and inefficient. Modern 2 stroke are eons ahead of this contraptions. Electronics and better oils that allow mix of 50:1, have made 2 stroke a much better machine than the smoky stuff from the 70ties. I have a collection of vintage Homelite chainsaw that are marked to take SAE 30 oil at a 16:1 ratio. Compare that with the 50:1 ashless oil of today.

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## ringtail

> I never understood how the 4-MIX engines worked, here is a video, and I still don't understand it   https://www.youtube.com/watch?v=cAHq118pEgI

  
Still working on 2 stroke principles of filling the crankcase with fuel mix then via a transfer port sending that compressed mixture to the inlet valve rather than a reed valve or other transfer ports. A good concept but no way is it capable of producing the  horsepower of a modern 2 stroke.

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## chalkyt

Honda 4 stroke for about four years now. Never missed a beat, change oil and filter annually. Good tap and go head but replaced by Husquvarna head when it wore out (I think the Husquvarna head is more robust). Very quiet, starts first go, deals with two acres easily (plus ride-on and Honda push mower of course).

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## Jon

In a "conventional" 4 stroke the oil supposed to be kept out of the fuel path and the combustion chamber and there is minimal consumed/burnt during operation.
As it has been pointed out by a few people, in this situation the oil is part of the fuel mix and is being consumed.  
I guess you would not need to change the oil, rather it would be keeping it topped up.

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## ringtail

> Honda 4 stroke for about four years now. Never missed a beat, change oil and filter annually. Good tap and go head but replaced by Husquvarna head when it wore out (I think the Husquvarna head is more robust). Very quiet, starts first go, deals with two acres easily (plus ride-on and Honda push mower of course).

  Try the shidawa speed feed head next time you need to replace. Awesome.

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## Marc

> Try the shidawa speed feed head next time you need to replace. Awesome.

  Yes, got that on my Stihl w/s and it is great. I managed to lose the spring inside though and the mob that sells it on e-bay don't sell parts for it. Improvised a spring with some wire but would like to buy the part.

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## Racer17

> It was the Honda that I saw it with, no doubt other makes have them too. http://powerequipment.honda.com.au/D...425_Bent_Shaft

  bought this about 4 months ago, super easy, very quiet, rarely need to squeeze the trigger unless you are attacking some thicker grass,

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## ErrolFlynn

Ended up buying a stihl.  Haven't gone through the tank of fuel as yet that was in it when purchased.  Was surprised to hear notions of 50:1 mix.  I've been so accustomed to mixing 15:1 for most machines I've used in the past that I wonder if this is some kind of planned obselecence - run it light on oil and it'll wear out faster.  Curiously, I was offered an additional 2 years warranty if I would buy a bottle of Stihl oil.  How could I refuse.  I find it hard to imagine oil in a bottle marked Stihl is any different from oil in a bottle mrked Shell, Caltex, Castrol, Valvoline etc.

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## johnc

There are magic enzymes in the Stihl oil that reverse the polarity in the googlewhatsit and destroy all those little mites that cause the wear and tear in the thingingme bit. All designed to have the machine fall apart two days after the warranty expires. Trust me, would I lie.

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## notvery

All the arborists / fencers / etc etc around my way us stihl. 
I did the same got the oil for the warranty with gritted teeth "how much for oil!!!", one bottle has gone a LONG way and thats with a stihl chainsaw/brushcutter and blower all using it, it may be more expensive but really its not worth the hassle to not...now the chain oil that is the one that i seem to be just opening the cap and pouring on the floor. 
I got the easy start on the Brushcutter and everytime i go to use it i curse how rubbish it is to start... and then i remember i have to put the trigger into the start position and it starts great... :Doh:  idiot idiot idiot. 
after nearly a year with my stihl tools i can only say they are quality brand. oh and i want a bigger chainsaw

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## Marc

Two stroke oil ratio has gone from 16:1 to 32:1 due to oil quality not for some conspiracy to destroy your motor. 
Outboard motors use 50:1 and go all day full blast for decades. Use more oil and you will be sorry.
There are many good quality 2 stroke oils that can be used in a chainsaw, the one thing to watch is, if it is for air cooled engine or watercooled. Use only oil for air cooled engines. 
Don't penny pinch on bar oil either. We used to use plain mineral oil for the bar, however without a viscosity additive the mineral oil just sprays off the nose of the bar in the ground. 
Stihl does not have a refinery so only relabeled someone elses oil. Most of the big brands have 2 stroke air cooled oil that works well. Stick to 32:1 petrol to oil ratio. There are some 50:1 oils around for air cooled but it is not worth the risk.

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## ringtail

Had this discussion just the other day at the small engine / mower centre. 50:1 for absolutely everything was their answer. Chainsaws, brushcutters, blowers, snippers, mowers whatever. If it's 2 stroke, air cooled with quality oil , 50:1 . So I replied ok, 40:1 for everything then. They looked at me funny.  :Biggrin:  Going to give the shindawa oil a try. Ducks nuts apparently and a touch cheaper than the others.

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## Marc

You can only use 50:1 ratio if the oil states 50:1
You can not decide to do 50:1 with an oil that states 32:1 just because. 
My vintage chainsaw's petrol cap has cast on it, 16:1 oil ratio. I use 32:1 2 stroke oil. If I did not have 2 stoke oil available and only SAE30 like it was in the 60ties, I would have to go 16:1.
Most low performance mowers used to be 25:1 SAE30. Modern 2 stroke air cooled can be used on the same engine at 32:1.
Stihl states on it's website to use Stihl oil at 50:1 ratio, however they say if you don't use Stihl oil, you must go 25:1. This is of course crap since "other" oils can be just as good or better than the one Stihl re badges and onsells. 
The race towards lower amounts of oil in 2 stroke engines is spurred by the specter of the green nazi movement. Anything to reduce smoke from the exhaust, including risking the integrity of the engine. Bar oil is no different. In Europe mineral bar oil is banned and they use vegetable oil. Next thing loggers will have to take bags to pick up their own droppings and bring them back home.

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## ErrolFlynn

I always fit a catheter before I go wood chopping in the bush in case I have the need to go before I get home.  Have I been wasting my time.

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## ringtail

Agree Marc. That's why I just buy quaity oil that states 50:1 and run 40:1 to be safe.

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## Smurf

Two stroke oils have performance ratings just like other engine oils do. 
FA - the lowest grade of lubrication and produces the most smoke. 
FB - good lubrication but no real improvement on the smoke. 
FC - good lubrication and less smoke. 
FD - synthetic. Not recommended for all applications but it's the highest grade as such. 
Brand doesn't necessarily indicated quality - have a look on the bottle and read what it says. 
Personally I use FC rated oil and have never had any trouble with it. Caltex sells it at their service stations and it's not overly expensive. Been using it since the 90's (and my two stroke whipper snipper is still going strong - 16 years old).

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