Stihl 044 help.

[mudfly]

@pioneerguy600 @lone wolf
Here is the requested video. H and L Screws are set 1 turn each.

View attachment FullSizeRender.MOV

It had run a little more prior to this but all were about the same result. With the need to choke, it feels like fuel delivery to me. But if I had the answers I wouldn’t be here.

 

[huskihl]

if you turn the H screw out 1 more full turn and hold the throttle wide open, what happens?

 

[mudfly]

if you turn the H screw out 1 more full turn and hold the throttle wide open, what happens?

Trying to see if the extra fuel counters an air leak? Meaning it should be way to rich unless there is an air leak?

Or what does this test do?

 

[lone wolf]

@pioneerguy600 @lone wolf
Here is the requested video. H and L Screws are set 1 turn each.

View attachment 1051249

It had run a little more prior to this but all were about the same result. With the need to choke, it feels like fuel delivery to me. But if I had the answers I wouldn’t be here.

First impression is the carb is not working right. But it could be a Vac leak. Vac test it again carefully and if good get a new OEM carb..

 

[SteveSr]

These also have a "factory design" air leak between the PTO shaft and the worm gear sleeve. Fill it up with thick grease before leak testing.

 

[mudfly]

These also have a "factory design" air leak between the PTO shaft and the worm gear sleeve. Fill it up with thick grease before leak testing.

I did run into that when I rebuilt it. Had to come here to figure out how that was supposed to seal. Didn’t make sense then, or now, but I did get it to seal.

 

[huskihl]

Trying to see if the extra fuel counters an air leak? Meaning it should be way to rich unless there is an air leak?

Or what does this test do?

That’s possible, but it also could rule out other things like the fuel filter or screen

 

[Ironhorsedoctor]

The IPL shows the HD-17D as USA Stihl part # 1128-120-0622. The HD-15D is part # 1128-120-0625
The IPL will show all the combinations of carburetors and air filters

 

[pioneerguy600]

@pioneerguy600 @lone wolf
Here is the requested video. H and L Screws are set 1 turn each.

View attachment 1051249

It had run a little more prior to this but all were about the same result. With the need to choke, it feels like fuel delivery to me. But if I had the answers I wouldn’t be here.

Just pulling this out of my hat here, are both the metal ring spacer and the collar washer that is needed in the end of the rubber manifold to keep the manifold flat for sealing against the back of the carb? I have found these missing on a few saws and it created an air leak even on saws that had tested fine on pressure n vac test.

 

[stihltech]

A bit of explanation on the hi speed nozzle. It is not so much high speed operation to be concerned about. The nozzle has an internal check valve that must seat for correct idle. One symptom is that you need to choke the saw for restart. Also you cannot open up the low speed needle to get enough fuel to compensate. It is an carburetor internal air leak in essence.
It is time to back up , do the PRESSURE AND VACUUM TEST (otherwise your are wasting your time). Check spark with a spark tester (not a plug with a regular gap). You have been given all you need in all these posts to diagnose the saw. Let us know after the testing is completed.

 

[billyboy]

Just curious as to why the rings look like they are recessed. Should’nt they be setting out at the edge of the piston or is it an optical illusion?

 

[mudfly]

A bit of explanation on the hi speed nozzle. It is not so much high speed operation to be concerned about. The nozzle has an internal check valve that must seat for correct idle. One symptom is that you need to choke the saw for restart. Also you cannot open up the low speed needle to get enough fuel to compensate. It is an carburetor internal air leak in essence.
It is time to back up , do the PRESSURE AND VACUUM TEST (otherwise your are wasting your time). Check spark with a spark tester (not a plug with a regular gap). You have been given all you need in all these posts to diagnose the saw. Let us know after the testing is completed.

It's next on my list. Didn't have time last night. Time in the garage/shop is the one commodity that is in short supply.

 

[Dean-O]

These saws are so easy to fix when I have them in my hands but trying to fix a problem over the net is like working blindfolded with my right hand ties behind my back. I have to commend mudfly for sticking with this thread and trying to solve his saw`s woes.

All day long the phone rings at my shop and a handful of times it’s someone wanting me to diagnose and fix there saw/lawnmower/string trimmer over the phone.

Sometimes I can help because the customer just flooded the unit, but other times I tell the customer to bring the unit in so we can look at it because it’s impossible for me to know what’s going on with nothing in front of me.

They keep going on and on, “should I buy a new coil?” “Is the piston worn?” “Maybe a new spark plug will fix it?”

The worst is the “it has no spark” 95% of the time the unit is burnt up and has plenty of spark. We tell this to the customer to pull the muffler and look at the piston and they insist they just need a new coil. I always tell them to bring the saw in and I will pull the saw over and pull muffler for them at no charge because if we sell an ignition once it’s installed we don’t take it back.

But to your point it’s frustrating trying to help customers over the phone that don’t want bring the unit in no matter what, even when we tell them we will give it a quick once over at the counter to narrow down what it could possibly be.

 

[Evan]

I think the 14 was the better carb. Though mine is running well with the 8 with a ported 46 cylinder. Has more than enough fuel at 3200ft

 

[mudfly]

Just pulling this out of my hat here, are both the metal ring spacer and the collar washer that is needed in the end of the rubber manifold to keep the manifold flat for sealing against the back of the carb? I have found these missing on a few saws and it created an air leak even on saws that had tested fine on pressure n vac test.

I think the rings are there. This is how it looks today. Trying to get set up for vac test .

 

[mudfly]

Pressure test results.

Held vaccum at -10 in Hg for 10 minutes.

Pressure started at 6 psi, bled down to 3 psi after 4 minutes. Bubbling out between the bushing and crank on the PTO side of the case. I did take the clutch and worm gear out so there is nothing pushing in on it to seal. It was originally installed with grease behind it.

2 things to note. Intake boot and impulse line were not included in this test. I don’t have a way to test with those on right now.

 

[pioneerguy600]

I think the rings are there. This is how it looks today. Trying to get set up for vac test .View attachment 1051452

Yes, that is the two pieces I had asked about.

Pressure test results.

Held vaccum at -10 in Hg for 10 minutes.

Pressure started at 6 psi, bled down to 3 psi after 4 minutes. Bubbling out between the bushing and crank on the PTO side of the case. I did take the clutch and worm gear out so there is nothing pushing in on it to seal. It was originally installed with grease behind it.

2 things to note. Intake boot and impulse line were not included in this test. I don’t have a way to test with those on right now.

A strip of rubber behind the carb is all that is needed to test the intake boot.

 

[mudfly]

Yes, that is the two pieces I had asked about.

A strip of rubber behind the carb is all that is needed to test the intake boot.

I was going to do that but I needed to hook the pump up to the barb for the impulse line. Can’t do that with the tank on the saw with what I have today. I can pick up a couple of other connecting pieces sometime yet this week to include those.

I figured that I would do the best test I could with what I had. It may not be perfect, but shows the crank seals and base gasket are all holding.

 

[pioneerguy600]

I was going to do that but I needed to hook the pump up to the barb for the impulse line. Can’t do that with the tank on the saw with what I have today. I can pick up a couple of other connecting pieces sometime yet this week to include those.

I figured that I would do the best test I could with what I had. It may not be perfect, but shows the crank seals and base gasket are all holding.

The hose barb in a twostroke sparkplug base adapter works good for that test.

 

[Mad Professor]

I was going to do that but I needed to hook the pump up to the barb for the impulse line. Can’t do that with the tank on the saw with what I have today. I can pick up a couple of other connecting pieces sometime yet this week to include those.

I figured that I would do the best test I could with what I had. It may not be perfect, but shows the crank seals and base gasket are all holding.

Piece of tygon from barb to pres/vac pump.