HELP - Trouble with 044 #2

[MustangMike]

I've been having trouble with 044 #2. It started a few weeks ago out of nowhere (it ran great the previous outing).

When cold, the saw will run for 20 or 30 seconds, then die. After that, you can get it to start but as soon as it reaches full RPM it dies.

I replaced the spark plug & fuel filter, and even tried to run it w/o the fuel filter. I rebuilt the carb, then replaced the carb with a new one.

Today, I ripped the saw down and thought I found the problem. There was a crack in my impulse hose. Even though it did not look like it went all the way through, I thought I had found the problem.

Found a store that had the impulse line and went and got it. Also tried to buy a new fuel line, but they did not have one!!!!!!

Put it all together, and it does the exact same thing. I'm very frustrated!

The impulse line was AM (I purchased OEM) and the fuel line is also AM. I thing it may be crushing (even though I have not seen it do it), so I plan to replace that next. The boot was OEM and looked fine.

If that is not the fuel line, I plan to replace the coil.

If anyone has any other suggestions, I would appreciate it.

Thanks,
Frustrated Mike

 

[old-cat]

I think your saw has an ego problem. You inflated its ego like a balloon and it popped!

 

[fearofpavement]

I highly doubt the symptoms you described are a bad coil. Sounds like a fuel issue. If you currently have two 044s, trading parts and trying to move the problem is an excellent troubleshooting technique.

 

[Moparmyway]

Rebuild the carb and get a genuine stihl hose and filter.

 

[windthrown]

Sounds like an impulse line... and as you fixed that, a fuel pump problem. That's what the impulse line drives in the carb. It could be a gas line, but usually they do not start if there is a crack in that line. So maybe a clogged fuel filter, a kink in the line, or a rock chip or metal flake in the carb?

From your description I would say that the saw is starving for gas for some reason. Pull the carb and use compressed air to >lightly< blow it out. Take the top off the carb and look at the screen. Pull the bottom and look at the impulse flapper. Maybe be a crack in that? Or a plugged up intake. Grit and sawdust are common clogging agents in the fuel line and carb.

 

[Trx250r180]

crank bearing on the flywheel side is going out

 

[MustangMike]

crank bearing on the flywheel side is going out

Brian, that is different than all the other answers. Why do you suspect that and how do I determine if that is what it is?

 

[MustangMike]

Sounds like an impulse line... and as you fixed that, a fuel pump problem. That's what the impulse line drives in the carb. It could be a gas line, but usually they do not start if there is a crack in that line. So maybe a clogged fuel filter, a kink in the line, or a rock chip or metal flake in the carb?

From your description I would say that the saw is starving for gas for some reason. Pull the carb and use compressed air to >lightly< blow it out. Take the top off the carb and look at the screen. Pull the bottom and look at the impulse flapper. Maybe be a crack in that? Or a plugged up intake. Grit and sawdust are common clogging agents in the fuel line and carb.

Yea, when I saw the crack in the impulse like I was sure I had found the problem. Thanks for the advice Windthown, and glad to see you posting again. I was considering sending you a PM to see how you were doing. After rebuilding the carb, and not finding any problems, then replacing the carb with a new one, I would be surprised if that is it. I guess dirt can do that, but I did not see any when I was in there.

I have seen other AM gas lines shrivel with suction, I'm hoping that is what mine is doing. Brian's take on it scares me, that is not a small job!

Something else I forgot to mention, the plug is usually wet when I pull it. That is why I'm starting to think it may be ignition related.

 

[windthrown]

Brian, that is different than all the other answers. Why do you suspect that and how do I determine if that is what it is?

Methinks he is pulling your plonker on that one...

 

[MustangMike]

I did not see any shorts in the wires, but is it possible that the kill switch is malfunctioning? How would I check that?

 

[Trx250r180]

Methinks he is pulling your plonker on that one...

Not pulling anything sir ,i have had 2 saws do exactly what he is saying start and die ,it was the lh flywheel side bearing going out ,if he keeps trying to start it without diagnosing ,the piston may get damaged ,the cage falls apart that spaces the bearings and they all go to one side of the race ,that is why it will start sometimes but once gets rolling the flywheel and coil get far enough away and lose fire,it also will suck air at the seal with the crank not centered ,take the recoil cover off and roll the flywheel by hand ,see if anything looks out of center
Hopefully i am wrong as i am often ,but it is something to look at ,with a case splitter you can usually do crank bearings in under an hour on a 044 saw

 

[windthrown]

Yea, when I saw the crack in the impulse like I was sure I had found the problem. Thanks for the advice Windthown, and glad to see you posting again. I was considering sending you a PM to see how you were doing. After rebuilding the carb, and not finding any problems, then replacing the carb with a new one, I would be surprised if that is it. I guess dirt can do that, but I did not see any when I was in there.

I have seen other AM gas lines shrivel with suction, I'm hoping that is what mine is doing. Brian's take on it scares me, that is not a small job!

Something else I forgot to mention, the plug is usually wet when I pull it. That is why I'm starting to think it may be ignition related.

I still post here, but not in the general forums much any more. Too many modders/experts/gods/noobs here that ~know it all~ and want to fight over what is inside a ping pong ball. Also if I post too much on threads like this I get way too many PMs and emails asking me to call and solve all kinds of saw problems. I am not the Shell Answer Man. So I post in the Aussie forum with my old friends down under there, and that is about it.

Try swapping the carb from your other 044 and see if it runs OK. If it does, the carby is the problem. If not, then there are other problems. You can also swap the coil from the good saw into this one, and see if it runs better. That would be the test I would run first (easy to do).

 

[mdavlee]

Swap coils if you can to eliminate that problem. It sounds like fuel to me. Usually if the coil or timing is off it will go to whatever rpm it wants to turn and just not go higher. The 046 slipped timing and would only turn 12k no matter what.

 

[pioneerguy600]

Not pulling anything sir ,i have had 2 saws do exactly what he is saying start and die ,it was the lh flywheel side bearing going out ,if he keeps trying to start it without diagnosing ,the piston may get damaged ,the cage falls apart that spaces the bearings and they all go to one side of the race ,that is why it will start sometimes but once gets rolling the flywheel and coil get far enough away and lose fire,it also will suck air at the seal with the crank not centered ,take the recoil cover off and roll the flywheel by hand ,see if anything looks out of center
Hopefully i am wrong as i am often ,but it is something to look at ,with a case splitter you can usually do crank bearings in under an hour on a 044 saw

On all of the Stihl saws that I have seen the Flywheel side bearing go out the flywheel will hit the module and leave scar marks on both. The saws would run but erraticly.

 

[windthrown]

Not pulling anything sir ,i have had 2 saws do exactly what he is saying start and die ,it was the lh flywheel side bearing going out ,if he keeps trying to start it without diagnosing ,the piston may get damaged ,the cage falls apart that spaces the bearings and they all go to one side of the race ,that is why it will start sometimes but once gets rolling the flywheel and coil get far enough away and lose fire,it also will suck air at the seal with the crank not centered ,take the recoil cover off and roll the flywheel by hand ,see if anything looks out of center
Hopefully i am wrong as i am often ,but it is something to look at ,with a case splitter you can usually do crank bearings in under an hour on a 044 saw

Weird. I never had a problem with bearings on any 044/440 saws. I had problems with bearings in 066/660 saws, but the engines ran fine even with friend bearings. Even after the oil pump was toast in one 066 the engine started and ran great. The bearing was loose when the clutch was wiggled.

The 'saw dies after running' is so typical of impulse lines in Stihl saws it is silly. I have had many go out on me that way from 021 to 660 saws. Also common in carb clogged saws. Have also had several saws stop running with cracked fuel lines. Wet plug may indicate other issues though, like the coil. I never had a flywheel fail on me either. I even super-glued a 210 flywheel fin on and it is still running, last I heard from my ex.

 

[Trx250r180]

Weird. I never had a problem with bearings on any 044/440 saws. I had problems with bearings in 066/660 saws, but the engines ran fine even with friend bearings. Even after the oil pump was toast in one 066 the engine started and ran great. The bearing was loose when the clutch was wiggled.

The 'saw dies after running' is so typical of impulse lines in Stihl saws it is silly. I have had many go out on me that way from 021 to 660 saws. Also common in carb clogged saws. Have also had several saws stop running with cracked fuel lines. Wet plug may indicate other issues though, like the coil. I never had a flywheel fail on me either. I even super-glued a 210 flywheel fin on and it is still running, last I heard from my ex.

I thought i saw he had replaced the carb and all the lines is why i ruled those out ,my string trimmer fs80 started and died like he is describing ,bought a new carb and it still runs good ,he could have got a bad carb though anything is possible ,i could not get one of my saws to idle and the crank bearing on the oil pump side was not seated all the way against the crank making it suck air a little ,the little 2 smokes are pretty touchy on how they run if have an air leak
I guess Mike could always block off the intake and exhaust ports and pull vacuum at the impulse and see if it bleeds down

 

[burnses]

pull the fuel line off the carb with tank empty and use a hand vac pump to put a vacuum on tank and make sure your tank breather is working

good luck

sap can

 

[windthrown]

Ah, damn, AS went down on me for a while...

I thought i saw he had replaced the carb and all the lines is why i ruled those out ,my string trimmer fs80 started and died like he is describing ,bought a new carb and it still runs good ,he could have got a bad carb though anything is possible ,i could not get one of my saws to idle and the crank bearing on the oil pump side was not seated all the way against the crank making it suck air a little ,the little 2 smokes are pretty touchy on how they run if have an air leak
I guess Mike could always block off the intake and exhaust ports and pull vacuum at the impulse and see if it bleeds down

I see now that he rebuilt and replaced the carb with a new one already. Missed that on my first read. So.... swap out the coil with a good one and test it. Also replace the fuel line, or test it with compressed air or my blowing into it (pull fuel line from the saw, plug one end, add air to the other see if there are leaks). Make sure the flywheel is rotating neatly by the coil, and that the coil is not set too far from the magneto. Some coils have slots and are adjusted too far from the magneto, though that usually does not cause these types of ignition problems. You can also pull the plug wire and test the ignition spark with another plug pressed against the jug. A little tricky when you have to pull the saw over by hand, but it can be done. If it is nice and blue it is not likely the problem. Though coils can fail in funny ways over the power curve. They also tend to get weaker over time.

I did not see any shorts in the wires, but is it possible that the kill switch is malfunctioning? How would I check that?

That is a common problem on the 026 saws. The thumb levers wear down and the kill switch metal tab gets out of kilter and fails to make contact. But that usually results in the saw running when you shut it off. You can test the coil kill switch and wires with an ohm meter. Also look at the lever metal tab to see that the contact is being made correctly. Also look at the black lead from the coil. Often times the insulation gets stripped and it can make contact with the saw body. Ohm meter will tell you if there is a short. With the lever set to run position, test with one ohm meter lead pressed to the coil kill wire tab and the other to the saw body.

 

[MustangMike]

Thanks, everyone, for the advice.

Brian, would I be able to feel play in the flywheel if the bearing is going bad?

It is an old saw, SN starts with 120.

 

[windthrown]

If the flywheel is out of alignment that much with the coil to cause ignition problems, you should be able to feel the play. Rattle it from side to side and up and down.

All 10mm 044s are early models and pretty old now.