Author Topic: Bar won't oil  (Read 162 times)

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Offline danders

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Bar won't oil
« on: February 11, 2014, 03:50:27 pm »
Hey guys, I've got a bar oiling problem with a friends saw that I can't seem to identify the source of.  It's a Husqvarna 340.  He brought it to me to check out and get running. The piston looked good and the intake appeared to be tight so I put some fuel in it and the saw fired right up but wasn't oiling the bar.  I found that the 540057901 Piston Pump gear was stripped so I replaced it and 503931801 PINION that drives it.  I did not replace the 537154801 hard plastic tube the piston pump rides in or the 503854801 rubber part that the plastic tube inserts into. 

I'm not getting a bunch of oil being pumped that isn't getting to the bar, it's like it's sucking air instead of bar oil.  I emptied the oil tank, sloshed a little fuel in there and blew air through the oil outlet at the pump back into the tank with the cap off to try to clear any crud that might be keeping oil from getting to the pump. I dropped the little basket filter on the bottom of the saw and everything looked clean there. The 503854801 rubber part looks okay to me, but I'm wondering if that may be the problem.  It's a crazy simple system with a minimal amount of moving parts; it baffles me that I can't figure out what's wrong.  The pinion appears to drive the piston pump properly, and the piston pump turns freely in the plastic tube. The plastic tube has opposing holes, and those are lined up with the related holes in the rubber seal.  I can't see any reason it shouldn't work, but it doesn't.  Anyone seen anything like this before? 

Dave

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Offline KilliansRedLeo

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Re: Bar won't oil
« Reply #1 on: February 11, 2014, 05:37:48 pm »
There is a vent in the oil tank beneath the bar protector 537040301, perhaps it is clogged. If no air is getting in the tank from the breather I don't the pump will function.
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Offline Philbert

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Re: Bar won't oil
« Reply #2 on: February 11, 2014, 09:56:38 pm »
Sounds like you have tried the basic stuff.

For what it's worth, my Husq 353 uses a different oil pump gear depending on whether it is fitted with a spur sprocket or a rim sprocket.  Really.  Could not believe this, but it is true.

Are you sure that you have the right part?

Philbert

Offline danders

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Re: Bar won't oil
« Reply #3 on: February 12, 2014, 11:09:43 am »
Thanks to both of you.  I could see where the tank vent could cause the problem.  I glanced at it last night but didn't have time to fiddle with it much. I probably won't have time until Friday.

Philbert - I wondered about the drive gear as well, because you can't see it turning the pump when the saw is assembled.  With the clutch and cover plate off it mates well though with the related gear on the piston pump.  I did verify that the part number on the new pinion matched the part number on the old.   

Dave

Offline Philbert

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Re: Bar won't oil
« Reply #4 on: February 12, 2014, 12:10:28 pm »
Does it also mate with the spur sprocket or splines on the clutch drum?

Long shot, I know.

Philbert

Offline danders

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Re: Bar won't oil
« Reply #5 on: February 18, 2014, 03:34:42 pm »
I finally got to work on the saw again on Sunday. The vent doesn't appear to be blocked, I can hear air being passed when blowing air in from the bar side of the vent. I had about 20 pounds showing on the air compressor so I suppose that it is impeding air flow at whatever level of suction the oil pump is capable of generating. The saw does pump bar oil with the bar off, I guess it's mainly a concern with the volume of oil being pumped. Normally I'd expect to see some oil thrown off the end of the bar but I'm not seeing that at all. The bar I'm using came off of a 353, and I eyeballed that the oil outlet is lining up with the hole in the bar. There's no adjustment to the oiler on this saw, what you get is what you get.

There's only two more parts to the oiler than the ones I replaced so I think I might pick those up. The saw isn't likely to see much use, but it bugs me that it doesn't seem right. I was able to verify that the pinion is being turned by the clutch and is also turning the piston pump of the oiler.

Dave

Offline aclarke

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Re: Bar won't oil
« Reply #6 on: February 18, 2014, 03:42:11 pm »
Are the oil holes in the bar clogged?

Offline danders

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Re: Bar won't oil
« Reply #7 on: February 21, 2014, 12:51:25 am »
No, I cleaned the bar up good. It must be sucking air, or maybe I'm just expecting too much.

Dave