HELP! LA (Idle Speed) Screw Problems

[jacktheripper]

I have several saws that do not die when the idle screw is backed all the way out, meaning that the throttle butterfly is all the way closed.

This has bothered the heck out of me, and I have done dozens of vac/pressure tests on these saws, swapped carbs, tested fuel lines, resealed intake blocks, and even resealed base gaskets. I have idled them and sprayed them down with carb cleaner even. They do not show symptoms of air leaks. Throttle shafts are not worn excessively, but a couple of them do have very slight movement - like very little. A couple of them have perfectly tight throttle shafts and butterfly valves.

If the saw idles at a good speed and seems to run fine, should I not worry about this? I'd love to hear all your thoughts.

Thanks

 

[jacktheripper]

Well I just bit the bullet and bought three OEM Tillotson throttle shafts and three butterflies for the hs-224's on my 266's. I'm hoping that this does it, but I'll probably stop my wild rampage after this.

 

[huskihl]

If the butterflies or screws have been dicked with, sometimes they don’t close completely. Or if they put the butterflies in backwards.

Loosen the idle screw and shaft screw and snap it shut several times to see if they’ll close further

 

[jacktheripper]

If the butterflies or screws have been dicked with, sometimes they don’t close completely. Or if they put the butterflies in backwards.

Loosen the idle screw and shaft screw and snap it shut several times to see if they’ll close further

This is unfortunately not the issue. They are closing fully in the position they like to be in without binding.

 

[Canadian farm boy]

Is the throttle link bent and holding the throttle open slightly?
Any “free play” in the throttle trigger?

 

[jacktheripper]

Is the throttle link bent and holding the throttle open slightly?
Any “free play” in the throttle trigger?

I checked both of those things. It is allowing for a full, natural close of the throttle.

 

[Woodwackr]

Have you called Ghost Busters?

 

[GMB74]

If the engine starts ok, idles at a decent speed and the clutch isn't engaged/ chain isn't moving I wouldn't worry about it.


Maybe the idle mixture is just a tad lean?

 

[hacskaroly]

I wouldn't worry about it.

There are a lot of technicians (motors, electronics...etc) that won't mess with something when it is out of its normal/tolerance but still performs correctly, there are others who are bothered by it working this way, want to figure out why and then get it back to the the correct state and working. I am one of those people who want to get things back in their correct state.

 

[EFSM]

There are a lot of technicians (motors, electronics...etc) that won't mess with something when it is out of its normal/tolerance but still performs correctly, there are others who are bothered by it working this way, want to figure out why and then get it back to the the correct state and working.

Correct. This may reflect against me as a tech, but I will let more slide on a customer's machine than my own, mostly because I'm super OCD about my own stuff.

 

[GMB74]

"I will let more slide on a customer's machine than my own, mostly because I'm super OCD about my own stuff."

I hear you. If you are a tech, you need to need to do a quality repair fast and cheap. If the customer's equipment works OK you have met that goal. (Actually you can only hit two of the above, but you know what I mean).

On your own stuff you have the luxury of wasting time and money trying to find out why it doesn't work the way the manual says it should.
Professional curiosity. BTDT. Sometimes I was able to figure it out. Sometimes not.

 

[EFSM]

"I will let more slide on a customer's machine than my own, mostly because I'm super OCD about my own stuff."

I hear you. If you are a tech, you need to need to do a quality repair fast and cheap. If the customer's equipment works OK you have met that goal. (Actually you can only hit two of the above, but you know what I mean).

On your own stuff you have the luxury of wasting time and money trying to find out why it doesn't work the way the manual says it should.
Professional curiosity. BTDT. Sometimes I was able to figure it out. Sometimes not.

We have a sign hanging in our shop:
A cheap job, quick....won't be good.
A cheap job, good....won't be quick.
A good job, quick....won't be cheap.

 

[sixonetonoffun]

Adjusting idle my 2065's zama was completely ineffective. It's happy place just where the chain stopped spinning. Last fall it was racing and I found the screw completely out of the threads but in the "boot". Could turn it all day long with no effect. Put it in the threads with a thin film of thread lock. Full adjustment from kill engine to engage chain.

My theory is it sucked air and the nail polish I used as thread locker fixed the air leak.

 

[davidwyby]

If it ain’t lean on H and holds tune it’s fine