What is the definition of '4-Stroking'

[GLOBOTREE]

Is it when your saw is running just right? How do you adjust the carb for that?

 

[12guns]

Is it when your saw is running just right? How do you adjust the carb for that?

If your saw if "four stroking" it's running too lean, too much air, not enough gas. While adjusting the high speed jet, you'll notice when turning clockwise, your saw will run much faster rpm's, and sound smoother (four stroke). As you back the "h" jet back where it was, the saw will almost get a sputtering sound in it as it runs a bit slower. that's where you want it...as you cut wood, it will demand more fuel and actually smoothen' out a bit.

There's my 2 cents.

 

[HiOctane]

If your saw if "four stroking" it's running too lean, too much air, not enough gas. While adjusting the high speed jet, you'll notice when turning clockwise, your saw will run much faster rpm's, and sound smoother (four stroke).

12Guns,i dont want to offend you,but the description you give is the reverse of the reality.When your saw is 4 stroking,it means you are running a too rich mixture,so the engine is blubbering running at lower rpm while running lean will give you more rpm and a better,smoother exhaust note.
Woodsman,be careful if you are not familiar with carb adjustment.The line between lean and rich condition is thin .

 

[Simonizer]

12Guns,i dont want to offend you,but the description you give is the reverse of the reality.When your saw is 4 stroking,it means you are running a too rich mixture,so the engine is blubbering running at lower rpm while running lean will give you more rpm and a better,smoother exhaust note.
Woodsman,be careful if you are not familiar with carb adjustment.The line between lean and rich condition is thin .

Starting with the low speed needle out 1 turn and the high speed needle out one turn, run the saw wide open with the bar and chain on, no load, open the high speed needle by turning the screw counter-clockwise. When it stops screaming and has a slight burble-like noise in the exhaust, that is 4-stroking. This is where you want to leave the setting. Under load the fuel-air ratio will be really close. HiOctane was right on the money here. Cheers.

 

[12guns]

That's what I meant...maybe it didn't come out right. I was under the impression that if you're setting your h speed jet out of the cut, you didn't want it running smooth...in other words, you want some "blubber" I thought the four stroke analogy was for the smoother running, no blubber setting. What I mean is to get the saw to the point of no blubbering...then back down to slight blubber. Right? It's obvious you don't want to run your saw too lean, or you'll burn it up, that not what I meant to reccomend.

 

[HiOctane]

if you're setting your h speed jet out of the cut, you didn't want it running smooth...in other words, you want some "blubber" . What I mean is to get the saw to the point of no blubbering...then back down to slight blubber. Right? .

This part is ok.Slight blubber out of the cut,then in the cut the note should change to a smoother one.

 

[GLOBOTREE]

Thanks 12guns and all. No I am not all that familiar with carb adjustment and I sure want it to be right. I just replaced the Walbro WT-239 on my Husky 41.
I have noticed in the past when cutting at full load that the sound would change back and forth. Kind of hard to put in to words, but the saw was runnin good.
It sounded like I was pumping the throttle a little,

 

[Newfie]

Isn't four stroking what Gypo,Marky,Hoffman and Dan get up to at the GTG?

 

[HiOctane]

Thanks 12guns and all. No I am not all that familiar with carb adjustment and I sure want it to be right. I just replaced the Walbro WT-239 on my Husky 41.
I have noticed in the past when cutting at full load that the sound would change back and forth. Kind of hard to put in to words, but the saw was runnin good.
It sounded like I was pumping the throttle a little,

If she was running with the sound changing back and forth as you say,it means you were running(condition in the cut)a BIT rich probably.The engine was going from "4 stroke to 2 stroke condtion" to explain it simply.

 

[rahtreelimbs]

Isn't four stroking what Gypo,Marky,Hoffman and Dan get up to at the GTG?

Only if you are the pivot man!

 

[Newfie]

Only if you are the pivot man!

I wouldn't want to steal dennis' job.

 

[RandD]

4-stroking = misfire

To limit the maximum speed of two stroke engines are used two posibilitys:

1. speed limitation by cutting off the ignition at high rpms
2. the natural enrichment function of the carburettor. With higher speeds, the air-fuelmixture is getting richer. At a certain point, the mixture is to rich for a good combustion. So the engine is missfireing and only every second or third revolution is a combustion. So we are talking about 4-stroking, when the two stroke engine behaves like a four stroke engine and is fireing not every revolution. This leeds to a drop down of the engine speed. By setting the adjustment of the carburettor to a leaner mixture, the maximum speed will increase and vice versa.

Greets

 

[Butch(OH)]

Ha! I used to feel a little stupid when I called the 4 stroking sound "Blubbering" But since Simon calls it "Burble-like" I am feeling like I'm kinda educated. Guess I have some cooth after all eh? Well don't I?

 

[rahtreelimbs]

Isn't four stroking what Gypo,Marky,Hoffman and Dan get up to at the GTG?

Only if you are the pivot man!

I wouldn't want to steal dennis' job.

I am sure he would step aside since you a probably used to being in that position anyway!

 

[Newfie]

I am sure he would step aside since you a probably used to being in that position anyway!

People who live in glass hou... err or is it people who make windows... how does that old saying go again...

 

[rahtreelimbs]

People who live in glass hou... err or is it people who make windows... how does that old saying go again...

Whatever it takes. I work to support my family and if it takes working for a window co. to pay the bills so be it!!!


And what is your claim to fame???