Saw loses power during LONG cuts

[Soundchasm]

Ken, tomorrow I'll take the bar off and run it to confirm the pump is working. Even if the RPMs are slow it should still be putting out some oil. Thanks.

 

[Soundchasm]

Original post said you'd poured the last of the fuel from a container. If you got some dirt along with the gas, you may have gotten the water from the bottom of the can too. (Unless you use non alcohol gas). It's happened to me until I could get gas without that crap in it.

Drain the tank, flush the lines and filter and fill it with Tru-Fuel till you get it running.

Just my thoughts.
Good luck!

I did clean the 1 GL gas container, dried it out, and then used fresh gas from the top of a 5 GL container to make a new batch. The saw got compressed air and a new fuel filter. The gas tank stayed empty for a few days, so I've tried to make sure no H20 is in the picture, but I have to keep this thought in mind. Thanks.

 

[Soundchasm]

Hopefully you guys will hear new information. For me, the fact I had no leftover parts or a bed spring sticking out is HUGE!!

It seems to start fine. You can hear it bog when I try to open the throttle, and when I hit the primer button when it was running it died.

I have an old habit back from before the first carb adjustment of opening the throttle with my foot while I pull the cord. Even though it wasn't strictly necessary anymore it does seem to start a little quicker.

I can't tell if it's burning the fuel in the line and dying or if any fuel seems to flood it out. This condition is above my pay grade.
Thanks.

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[KenLockett]

Ken, tomorrow I'll take the bar off and run it to confirm the pump is working. Even if the RPMs are slow it should still be putting out some oil. Thanks.

Correct. What I noticed when the pump was not working is that VERY quickly the bar would heat and seize in the bar thus not turning or very difficult to turn. When I finally took the bat and chain off absolutely zero oil was flowing as the pump was completely shot. I was out cutting without winter weight oil in extremely cold temps. Husqvarna dealer who replaced pump for me (under warranty by the way) said the plastic pumps they use these days are absolutely junk and can be destroyed in the manner very easily. There is a thread I started somewhere on here regarding this very incident last winter. Good luck.

 

[Soundchasm]

Correct. What I noticed when the pump was not working is that VERY quickly the bar would heat and seize in the bar thus not turning or very difficult to turn. When I finally took the bat and chain off absolutely zero oil was flowing as the pump was completely shot. I was out cutting without winter weight oil in extremely cold temps. Husqvarna dealer who replaced pump for me (under warranty by the way) said the plastic pumps they use these days are absolutely junk and can be destroyed in the manner very easily. There is a thread I started somewhere on here regarding this very incident last winter. Good luck.

Ken, the oiler is definitely working. Bar and chain off, engine starts and we're making a puddle. So that's good, then. I've got some old 30W gear oil I might mix in with the stuff already in the saw to get rid of it

Today's saga so far is that the engine bogs on acceleration and will run for 30 seconds max before dying. Even though I blew air through all the fuel hoses, they're the only thing I didn't change (because they hadn't arrived). They've showed up today and I get a clue about how they go in. Looks to be an epic battle on the horizon... I know I'm missing the smallest fuel line, but I was able to physically clean that one as good as can be.

I turned the low carb adjust to all the way to "ridiculous", 1/4 turn at a time with no effect.

-cleaned the gas container
-new fuel mix with new fuel
-new fuel filter
-cleaned air filter
-checked oil pump
-exhaust screen not dirty, now very clean
-new carb
-piston=no visible damage
-new plug
-cleaned Husky tank
-new Oregon bar/chain

 

[jatoxico]

I turned the low carb adjust to all the way to "ridiculous", 1/4 turn at a time with no effect.

Off hand I don't think the low circuit (closest to engine) is the problem. It was idling. Did you try doing the same w/ the high speed adjustment screw?

 

[Soundchasm]

Off hand I don't think the low circuit (closest to engine) is the problem. It was idling. Did you try doing the same w/ the high speed adjustment screw?

Yeah, I've had both screws set from off to (now I remember!) "Ludicrous speed". I just replaced two fuel line and it's the same scenario. I guess the next step (or the first step that I skipped) would be some kind of vacuum or pressure test.

BTW, JT, if you ever need to get the carb off, this is a lifesaver.

 

[jatoxico]

BTW, JT, if you ever need to get the carb off, this is a lifesaver.

That's good to know.

I just replaced two fuel line and it's the same scenario.

Fuel filter OK and exhaust screen's clear? Starting to run out of things. Hopefully it's not something with the piston.

 

[saskwoodburner]

Hopefully you guys will hear new information. For me, the fact I had no leftover parts or a bed spring sticking out is HUGE!!

It seems to start fine. You can hear it bog when I try to open the throttle, and when I hit the primer button when it was running it died.

I have an old habit back from before the first carb adjustment of opening the throttle with my foot while I pull the cord. Even though it wasn't strictly necessary anymore it does seem to start a little quicker.

I can't tell if it's burning the fuel in the line and dying or if any fuel seems to flood it out. This condition is above my pay grade.
Thanks.

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I'm no expert, but maybe we can get to some point where it's running better. I'll go on the assumption that the parts are all good, and the saw needs a tune.

When you start the saw, is it on full choke? Say it was a cold start. Is it full choke, 2-3 pulls and a burp, half choke, 1-2 pulls and go, then a blip of the throttle to to drop it off fast idle, and idle normal? Do you leave the chain brake on?

From the video it sounds (to me, not an expert!) like it's idling way too fast after you blip the throttle.

Is it possible the idle speed is set too fast?

If you fire it up and blip the throttle, then disengage the chain brake, does your chain do nothing, does it creep, does it run full speed?

 

[Soundchasm]

That's good to know.



Fuel filter OK and exhaust screen's clear? Starting to run out of things. Hopefully it's not something with the piston.

The exhaust filter wasn't pristine but it wasn't completely sealed. Walked away from this post and cleaned, but it was fine. BTW, it's a 5mm allen wrench for the muffler.

I found at least one Youtube vid where the guy talks about a pesky air leak around the boot. Says it results in the saw running lean in the cut but of course it's normal on the bench. But mine's not normal on the bench!!

 

[Soundchasm]

I'm no expert, but maybe we can get to some point where it's running better. I'll go on the assumption that the parts are all good, and the saw needs a tune.

When you start the saw, is it on full choke? Say it was a cold start. Is it full choke, 2-3 pulls and a burp, half choke, 1-2 pulls and go, then a blip of the throttle to to drop it off fast idle, and idle normal? Do you leave the chain brake on?

From the video it sounds (to me, not an expert!) like it's idling way too fast after you blip the throttle.

Is it possible the idle speed is set too fast?

If you fire it up and blip the throttle, then disengage the chain brake, does your chain do nothing, does it creep, does it run full speed?

Thanks for the help.
It has been-
Primer bulb 3x+
Choke on
Pull 2-3x for a burp
Pull again and it fire
click the trigger to get off half-choke and let it warm up.

The idle is set pretty fast for sure. I'll try backing it down tomorrow but I had to start guessing somewhere and at least it was running.

If it decides to run for the full 30 seconds that seems to be the current limit, I can get the chain to rotate but not much more, so it creeps. Full speed is out of the question.

Hope this helps.
I don't use the chain brake unless I see an OSHA truck in the neighborhood!!

 

[saskwoodburner]

Thanks for the help.
It has been-
Primer bulb 3x+
Choke on
Pull 2-3x for a burp
Pull again and it fire
click the trigger to get off half-choke and let it warm up.

The idle is set pretty fast for sure. I'll try backing it down tomorrow but I had to start guessing somewhere and at least it was running.

If it decides to run for the full 30 seconds that seems to be the current limit, I can get the chain to rotate but not much more, so it creeps. Full speed is out of the question.

Hope this helps.
I don't use the chain brake unless I see an OSHA truck in the neighborhood!!

I think you'll get closer to somewhere once you turn down the idle (counter clockwise of course). Just spent time watching tv with the better half, and I don't recall if you mentioned your high/low settings, how many turns out for each.

 

[jrems]

You can see the chain starting to move at idle. The idle speed is too high. Lower the idle speed, then try to adjust the low and then the high. Set both the low and high and set to factory specs. Are you sure the impulse line going from the engine to the carb diaphragm is not cracked? Was that the other line in the picture? Also when you had the muffler off did you check to make sure the screen was not completely plugged up with carbon?

 

[Jon1270]

I haven't watched the video (too early in the morning, others sleeping) but I like the impulse / fuel pump idea. Bogging on acceleration sounds like a lack of fuel. It might be that the only fuel it's getting is the gas you pump into the metering chamber with the primer bulb. Have you tried continuously pumping the primer bulb after starting to see if that allows it to run?

It's quite a bit different from the 200 and 300-series Huskies I've worked on, so I'm not sure how the impulse connection is made, or exactly where a leak might be most likely. Looking at the exploded parts diagram, I can't even find a separate impulse hose.

 

[Soundchasm]

You can see the chain starting to move at idle. The idle speed is too high. Lower the idle speed, then try to adjust the low and then the high. Set both the low and high and set to factory specs. Are you sure the impulse line going from the engine to the carb diaphragm is not cracked? Was that the other line in the picture? Also when you had the muffler off did you check to make sure the screen was not completely plugged up with carbon?

I'm concluding that the impulse line is the little short one going from the bulb to the bottom of the carb. It was clear and when I stretched it there were no cracks. The exhaust screen was not plugged and is completely clear now.

 

[Soundchasm]

I haven't watched the video (too early in the morning, others sleeping) but I like the impulse / fuel pump idea. Bogging on acceleration sounds like a lack of fuel. It might be that the only fuel it's getting is the gas you pump into the metering chamber with the primer bulb. Have you tried continuously pumping the primer bulb after starting to see if that allows it to run?

It's quite a bit different from the 200 and 300-series Huskies I've worked on, so I'm not sure how the impulse connection is made, or exactly where a leak might be most likely. Looking at the exploded parts diagram, I can't even find a separate impulse hose.

The subtle location of the impulse line in the diagrams is so subtle that I didn't order one... The diagram is the one with the primer bulb, assembled carb, and inlet pipe.

As of now, hitting the primer bulb while idling kills the saw.

 

[Jon1270]

I'm concluding that the impulse line is the little short one going from the bulb to the bottom of the carb. It was clear and when I stretched it there were no cracks. The exhaust screen was not plugged and is completely clear now.

Nope, that's not the impulse hose. The impulse connects from the carb directly to the motor, and uses changes in crankcase pressure to drive the fuel pump that's built into the carburetor. The difficulty is that it may not even be a hose; it may just be a passageway through the parts that connect the motor to the carburetor.

 

[Soundchasm]

Nope, that's not the impulse hose. The impulse connects from the carb directly to the motor, and uses changes in crankcase pressure to drive the fuel pump that's built into the carburetor. The difficulty is that it may not even be a hose; it may just be a passageway through the parts that connect the motor to the carburetor.

Then we may be onto something because I would have never looked for something I can't see.
Right now the saw will run for 30 seconds and die.
I have it packed up to take to the shop to let the pros have at it, but my first choice doesn't do Husky!

 

[jrems]

If there is a primer bulb there is probably a second line that's a tank return. Since the fuel tank on a saw is lower than the carb it needs the pressure in the engine to drive a diagram pump in the carb. That's the impulse line. It's common for them to crack. It could have been the issue all along. I haven't seen a saw without one.

Let us know what the tech says

 

[Soundchasm]

Well, I got it back from the tech the other Saturday, and the verdict was NONE of the above!! He poked around in there a bit and found a wire with a few cracks in the jacket (think it was the kill switch bit). He covered it (them?) and replaced the sparkplug wire for good measure. It began to run and he adjusted the carbs. I guess he figured that the spark was going someplace other than where it was needed. His initial observation was that the engine couldn't "use" the gas. He said if it was a 4-stroke the timing would be extremely retarded. He was going to look into a coil(?), but he checked the wiring in the meantime.

Anyway, it runs and I swear it runs better than new. My imagination told me it ran longer on a tank of gas today, because I finally got back out to that big limb. I buried the little bugger in some 28" rounds and opened the throttle and had at them. It takes a minute but the the outcome is not in doubt, sure and steady, and not really that slow.

I'm really happy with this saw and I'm thrilled it wasn't really broken. With the crash course I got in maintenance, I think I can keep it running for a long time. I can't thank you guys enough for your patience and counsel. I think I'll get an 18" bar and chain for the larger beasts, but 95% of the time, the 16" gets the job done.

As far as this little saw goes, it's hard to comprehend how much violence in under control in the little kerf!!

 

[Soundchasm]

Big props to Toby with Beavercreek Mower Repair here in Dayton. He's a one-man show, so he can't chat and work at the same time, but he was a drink from a firehose on possibilities and information. He was making 2-cycle oil recommendations at one point and started quoting motor oil specs!! He undercharged me by a significant amount. I made a nominal effort to combat that. How wonderful to have that opportunity.

 

[Sean McGillicuddy]

This looks like you learned a lot doing the repairs yourself!
I enjoyed the post and I will try to retain some of what your learned as well.
Glad all is running better!