Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Husqvarna => Topic started by: 3000 FPS on October 30, 2015, 10:31:21 pm

Title: Husqvarna K960 concrete saw.
Post by: 3000 FPS on October 30, 2015, 10:31:21 pm
Well the Husky K960 with the bad crank bearing was given up for scrap.  The customer decided it was not worth rebuilding and bought a new one.    So I asked if I could have it and so it is now mine.   I will tear it down and if the rod bearings look good I will rebuild it.   Not a bad freeby.   I will to take a few pics.
Title: Re: Husqvarna K960 concrete saw.
Post by: aclarke on October 30, 2015, 11:02:39 pm
Is that crank common to any other saw motors?
Title: Re: Husqvarna K960 concrete saw.
Post by: 3000 FPS on October 30, 2015, 11:41:39 pm
Is that crank common to any other saw motors?

That I do not know.  I have replaced the piston and cylinder on these before but have never split the case on one.  This should be a good project and very educational for me since I work on these things all the time.
Title: Re: Husqvarna K960 concrete saw.
Post by: Cut4fun . on October 31, 2015, 10:48:58 am
Well the Husky K960 with the bad crank bearing was given up for scrap.  The customer decided it was not worth rebuilding and bought a new one.    So I asked if I could have it and so it is now mine.   I will tear it down and if the rod bearings look good I will rebuild it.   Not a bad freeby.   I will to take a few pics.

There have been times I wish I had picked up the newer stihl 460 version I was offered with bad topend. I dont need one but have ran into a time or 2 since I wish I had had one.
Title: Re: Husqvarna K960 concrete saw.
Post by: Cut4fun . on October 31, 2015, 10:53:01 am
K960 crankshaft  544983901 $200 for new oem kit with bearings etc. 
Title: Re: Husqvarna K960 concrete saw.
Post by: 3000 FPS on October 31, 2015, 12:05:13 pm
K960 crankshaft  544983901 $200 for new oem kit with bearings etc. 

That is a lot cheaper than I thought it would be.  If I can rebuild this saw for less then 300.00 dollars it would be worth it.
Title: Re: Husqvarna K960 concrete saw.
Post by: aclarke on October 31, 2015, 03:24:09 pm
Looks very close to a 576 crank. I may have a few if you wanna post the specs, I'll check
Title: Re: Husqvarna K960 concrete saw.
Post by: 3000 FPS on October 31, 2015, 06:35:46 pm
Pic of the saw.

Title: Re: Husqvarna K960 concrete saw.
Post by: 3000 FPS on October 31, 2015, 07:39:22 pm
I took a few more pictures of the K960.  I just wanted to show the outside view of the cylinder.

Those runners coming from around the exhaust port and then to the sides of the cylinder are the transfer ports.   Just thought you guys might be interested in seeing that.
When I take the cylinder off I will take some more pics of it to show them better.

Click on the images to enlarge.
Title: Re: Husqvarna K960 concrete saw.
Post by: Cut4fun . on October 31, 2015, 08:28:49 pm
Reminds me of the 576 cylinder http://www.ebay.com/itm/HUSQVARNA-576XP-CYLINDER-PISTON-KIT-OEM-KIT-51MM-PART-575257406-/141088793385
Title: Re: Husqvarna K960 concrete saw.
Post by: 3000 FPS on November 02, 2015, 12:52:42 pm
I had posted some of this in the what is on your bench but decided to continue over here so that I could find it a lot easier later if needed.

I had diagnosed this with bad crank bearings especially on the PTO side.   I have all torn down now and when I got to the bearings I was correct on the bearings. 

Check out those transfer ports coming out of the crankcase.   Since I usually have torn down a lot of older saws I do not see this.  Cool stuff.
Title: Re: Husqvarna K960 concrete saw.
Post by: 3000 FPS on November 02, 2015, 12:54:23 pm
A few more pictures of the saw torn down.

I have all the parts I need on order from Jack's small engine.  I decided to replaced the crank because I could feel a very small amount of up and down movement in the big end bearing.
I am getting a new crank, bearings, small end rod bearing, all the gaskets, new crank seals, and new rings for 270.00 with shipping.   I am pretty satisfied with that and the saw should really do well when done. 

How about those removable crank stuffers.
Title: Re: Husqvarna K960 concrete saw.
Post by: 3000 FPS on November 02, 2015, 01:03:07 pm
I believe this saw is rev limited to around 10k rpm's so I will put back together completely stock. 
Title: Re: Husqvarna K960 concrete saw.
Post by: aclarke on November 02, 2015, 03:55:39 pm
Main crank bearings look shot!!! Hahaha
Title: Re: Husqvarna K960 concrete saw.
Post by: Cut4fun . on November 02, 2015, 04:28:38 pm
Do you want me to split that other info out and move into this thread? 

What cc is it because that topend looks like that 576 topend.
Title: Re: Husqvarna K960 concrete saw.
Post by: aclarke on November 02, 2015, 06:12:56 pm
56mm I believe.  38mm stroke
Title: Re: Husqvarna K960 concrete saw.
Post by: Cut4fun . on November 02, 2015, 06:18:11 pm
That made me search. Thanks.

Copy paste

Displacement, cu in (cc) 5.7 (94)
Power, hp (kW) 6.1 (4.5)


The Husqvarna K960 cut-off saw is a powerful hand-held power cutter, featuring the revolutionary X-Torq® engine technology. It is a unique machine, in a class of its own when it comes to emission levels, efficiency and maneuverability. This model was replaced in 2011 by the K970, but we have a couple of K960 16-inch saws available - while they last!

    Cuts curbstones and pavers in landscaping.
    Pipe cutting in installation work.
    Asphalt cutting in roadwork and pre-cutting in pipe trenches.
    Metal cutting.

Benefits:

    The new Active Air Filtration™ is one of the most efficient air filtration systems on the market, delivering operational times (dry cutting) of about one year with no filter service required.
    Engine with X-Torq® produces more power, higher torque and 75% fewer emissions.
    SmartCarb™, a built-in automatic filter compensation, maintains high power and lowers fuel consumption.
    DuraStarter™, the dust-sealed starter, and the durable starter cord reduce the risk of downtime and increase reliability and service life.
    The Poly V-belt provides better power transmission, less retensioning and increased product life.
    Efficient vibration and sound dampening make the machine more convenient to use.
    DEX, dust-handling system, provides cleaner cutting with less water usage.
Title: Re: Husqvarna K960 concrete saw.
Post by: aclarke on November 02, 2015, 07:29:35 pm
Sounds like a 90cc strato motor is already in their stable....
Title: Re: Husqvarna K960 concrete saw.
Post by: Cut4fun . on November 02, 2015, 08:22:27 pm
Sounds like a 90cc strato motor is already in their stable....

I had caught that too. 94cc 
Title: Re: Husqvarna K960 concrete saw.
Post by: 3000 FPS on November 02, 2015, 11:22:13 pm
Thanks for posting that Kevin.   If you want to move the info over that would be ok.    When I get all the parts and get it put back together I will get some more pics.   The saw I think was really easy to work on.  It came apart real easy.
Title: Re: Husqvarna K960 concrete saw.
Post by: 3000 FPS on November 02, 2015, 11:24:25 pm
Main crank bearings look shot!!! Hahaha

Yea that was on the PTO side and I could feel sideways movement in it.   This one is a 14" cut off wheel.
Title: Re: Husqvarna K960 concrete saw.
Post by: Cut4fun . on November 03, 2015, 12:32:15 pm
Merged so it moves back to Oct 30 now
Title: Re: Husqvarna K960 concrete saw.
Post by: SawTroll on November 03, 2015, 01:11:33 pm
Sounds like a 90cc strato motor is already in their stable....

Has been for quite some time, but likely too heavy and bulky to be suitable for chainsaw use?
Title: Re: Husqvarna K960 concrete saw.
Post by: aclarke on November 03, 2015, 02:18:05 pm
Likely need a saw specific crankcase but seems like it would be cost effective to use  common parts, ie. Crank, piston, etc
Title: Re: Husqvarna K960 concrete saw.
Post by: 3000 FPS on November 03, 2015, 07:29:25 pm
Sounds like a 90cc strato motor is already in their stable....

Has been for quite some time, but likely too heavy and bulky to be suitable for chainsaw use?

I agree, just the air filter set up alone is really bulky but for concrete dust is works pretty good.   
Title: Re: Husqvarna K960 concrete saw.
Post by: 3000 FPS on November 14, 2015, 10:56:17 pm
Got the new bearings pressed into the case today.  Put in the new crank and gasket and put the piston with new bearing on.    After getting the new crank and comparing it to the old one I am glad I got it.   Plus it looked a little discolored at the big end.  They were suppose to send two rings but I only recieved one so have to call them Monday.   So far the saw is going back together very easy.   The crank spins nice and free.
Title: Re: Husqvarna K960 concrete saw.
Post by: dynodave on November 19, 2015, 01:47:23 pm
If you've still got this ripped apart, Ive got a question about the original crank.....
On my Partner K700 (which IMO is the origin of the later husky chop saws) and my friends 272K, both cranks get oil mist to the clutch bearing from inside the crankcase, unlike the regular 272 wood saw which you can shoot oil/grease from under the clutch cover.
I discovered this since I was to rebuild the chop saw with a 272xp core provided as parts. I then discovered the cranks are not the same and the partner replacement had NO provision at all ...for grease on the clutch bearing except manually from the outside by dismantling the belt clutch.

If you look at the side profile of your husky 960 and a old partner the styling is unmistakeable. The old 272k and 3120K are of modified chainsaw origin with an unused oil tank. The old husky owned partners are a chopsaw dedicated design without a chainsaw oil compartment.
Thanks
Title: Re: Husqvarna K960 concrete saw.
Post by: 3000 FPS on November 19, 2015, 10:39:15 pm
I have worked on some partner K950's that look just like the Huskys.   What is it on the crank that I am suppose to see that allows for this mist lubrication of the clutch bearing.  I still have the original crank and I have not put the cylinder back on yet.
Title: Re: Husqvarna K960 concrete saw.
Post by: dynodave on November 20, 2015, 11:28:02 am
If I look at both cranks there is a little hole in line with the clutch bearing. The 272xp crank has the drilled passage that leads to the end of the crank, while the K272 crank is drilled to the inside/center of the crank. The chop saw crankcase pressure should blow away the grit AND lube the bearing.

On my K700 partner the original crank was the same as the K272, but the new aftermarket crank had no provision for oil/grease at all.  So I'm curious how the K960 crank is finished and if there is any provision for clutch bearing lube. My friend had bought a K960 and my rebuild of his husky K272 was for his spare/backup. 
thanks
Title: Re: Husqvarna K960 concrete saw.
Post by: 3000 FPS on November 20, 2015, 01:37:55 pm
Ok I looked at the crank that I removed from the saw and it does have a small hole where the clutch bearing sits.   The new crank shaft I ordered and put in the saw also has that same hole in the same location.    I took a guitar string and shoved it thru the hole and it does comes out through the center of the crank shaft and counter weight.   I really do not know if I like that design.  The crank case was pretty clean when I took it apart so I guess it must work.
Title: Re: Husqvarna K960 concrete saw.
Post by: aclarke on November 20, 2015, 04:10:53 pm
Hole correpsonds to a a pressed on brass metering plug on the crank throw. As on 3120xp  and others.
Title: Re: Husqvarna K960 concrete saw.
Post by: 3000 FPS on November 20, 2015, 05:31:53 pm
Hole correpsonds to a a pressed on brass metering plug on the crank throw. As on 3120xp  and others.

Have you ever plugged it up?
Title: Re: Husqvarna K960 concrete saw.
Post by: 3000 FPS on March 31, 2016, 08:51:37 pm
Well today I finally decided it was time to put the K960 back together.   I put the cylinder on, gad tank back on, the handle back on, the muffler, and all the covers.    Took it out to the garage and fired it up.   
The saws runs great.   Idles like it should and revs up good.   I just need to get a diamond wheel for cutting concrete with it.   This saw should last a long time having a brand new bottom end in it now. 


It took more time to clean everything than it took to put back together.

Title: Re: Husqvarna K960 concrete saw.
Post by: 3000 FPS on April 03, 2016, 02:20:35 pm
Well I got the diamond blade put on today and tried it out in some concrete pavers I had here that I use for stacking wood on.
I was impressed at how easy that saw cuts through this stuff.

Title: Re: Husqvarna K960 concrete saw.
Post by: Cut4fun . on April 03, 2016, 02:23:08 pm
Be neat to have on hand when needed for sure.  Sometimes I wished I would have grabbed the builders offered to me in different makes.

Nice job on the rebuild etc.  8)


Title: Re: Husqvarna K960 concrete saw.
Post by: 3000 FPS on April 03, 2016, 02:27:39 pm
Be neat to have on hand when needed for sure.  Sometimes I wished I would have grabbed the builders offered to me in different makes.

Nice job on the rebuild etc.  8)



Thanks Kevin.   The saw turned out great.   Starts on one pull and runs very well.    For a junker that was going to be thrown away I am very glad I got it.