Service & Maintenance Question
I have a 3120. Got it in 2013. Saw was working great ever...
Service & Maintenance Question posted July 13, 2015 by Don Bratz
548 Views, 13 Comments
Question:
I have a 3120. Got it in 2013. Saw was working great ever time I fired it up until this spring. I started it, ran it for ten minutes or so, shut it off and went to the job site. Tried to start the saw but nothing happened. Have tried repeatedly with no start. I am getting spark and I am getting fuel. HELP!
Thanks. Don Bratz
Thanks. Don Bratz
Answer
Check you compression as you at least 100 psi to start. With it running earlier it might be struck ring causing lack of compression. Another thing to check for is a clogged spark arrestor on the muffler.
If it is not either of these then it could be timing issue with the flywheel.
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Eugene your initial tip looks like it may pay off. See Robert's tip below. After checking the compression last night I found that it was just over 75 pounds. I am going to follow the suggestion posted by Robert and see where that leads me. Hopefully to a working saw. Thanks.
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that saw needs to compress at least 120lbs to run at all. I have re-built this engine on a few occasions. I am certain I know what the problem is.
the CRV was made by a sub-standard supplier during this production time-line. unfortunately, Husqvarna continues to use this supplier.
use a pick hook to retract the compression valve into the closed position, then use a Velcro strap to hold throttle trigger WOT, secure the saw with your boot tip and slowly pull up to compression tension, then let er rip. it will fire up even if it was flooded before by closing the choke gate.
I believe your CRV is sticking in the open (depressed) position. this will not allow the saw to start ever. it can only make it up to 100 lbs with the valve open.
until you replace that CRV, I have a perfect remedy that I developed.
take my advice don, go to o'rielly's auto parts and buy a 2 pack of fuel injector O-rings for a ford triton v-8 engine. cost under $2.00
pull off the cylinder cover and roll the O-ring over the CRV button, let it fall between the top-cap & the button. it will appear to be sloppy because the inside diameter is much bigger than the valve stem. but it will act as a limiter when you push the valve downward. the O-ring will retract the valve upward just enough that it will snap shut as the upper compresses the atomization enough to light the candle. this is a tried and true remedy and costs virtually nothing.
good luck sir, and let me know the results. I like to hear success stories. Robert...
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Thanks Robert. What you have said makes perfect sense. I am optimistic and am going to give it a try. I use this saw for my Alaska mill. I have been so discouraged because the power head has very few hours on it and we all know how much one of these costs. I am a bit disappointed with Husqvarna even though I am a diehard fan of the brand.
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Well Robert the saw is running. Here is what I found. The decompression valve was not sticking but it had worked itself loose. I tightened it. Also, while I had the cover off I looked at the magnets on the fly wheel and noticed a coating of oxidation. Lightly sanded with some fine grit sand paper. put everything back together and the saw fired up on the first pull. Your thoughts led me to the discovery. Thanks a lot.
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Eugene, how are you. not busy at all i'm sure. I am 52 tools deep today. the waiting list gets longer this time of year. I have only had 3 customers storm out with their junk, cussing because I haven't even looked at the issue yet. pushing out everything I can as quickly as possible. but it will not cut into my beer drinking time, regardless. just ordered an entire top-end for Hilti DSH 700 14" concrete saw. customer ran straight 91 no jaso oil. burned it up in one cut. $340.00 parts only. $200.00 shop hours. what is the inside diameter of the jug? I need to buy a hone to try to save the cylinder. let me know if you find the info. thx, Robert...
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Not too busy at all; really can stand to busier. Since I moved here The local are just trying me out with thier worst problems that no one else will even touch. I getting a lot of screw ups where who ever attempted repairs should just quit. I even got one push mower with the blade duct tape on. What killing my turn around time right now is parts delivery.
As for the cylinder size I have no idea here without measuring one and I don't have one here. I have tried honing these 2C cylinders before and it is usually a waste of time especially if you wear through the lining. Regular hones won't work. Ball flex hones will work to clean the cylinder without too much damage but they can quickly wear through those harden liners quickly and you got to use the right medium and grit. Most 2Cs that I work on are consumer and commercial grades and there is no oversize pistons available that I know of.
Here is a good source for the hones. http://www.enginehones.com/
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hello Eugene and don. so far I have come up with this. hilti DSH 700-35 14" concrete saw has a displacement of 68.7 cm3 or 68.7cc
so I am guessing that puts it into the 51mm piston range or thereabout. my wifi is total doodoo so research is virtually impossible right now. the flexhone that I need for this bore should demonstrate which diameter range?
if you guys have the necessary math skills to arrive at a correct flexhone size then please help.
thanks for any assistance you guys can offer. Robert...
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thanks for the advice Eugene, I will look at those hones tonight... Robert...
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that is super mr. bratz... I am very happy to hear it when a diy'er chases down the gremlin and resolves the issue.
in answer to the idea of just simply not using a compression relief valve any longer, certainly we don't need it, however, with a man sized saw like the 3120, the recoil really should enjoy the assistance of it. I demand a lot of my saws, but I always treat them like they are a most welcome part of my family. I thoroughly clean up like I mean it, sometimes several times during an outing. I store my saws empty always and use 91oct straight refined fuel never any ethanol blended fuel. especially on a high performance little gem like that saw. remember, jaso forms a molecular bond with refined gasoline, so it gets vacuumed into that jug every drop. but jaso does not form any bond at all with ethanol and that guarantees pre-mature loss of compression. so if you feel like I do about your saws you will never compromise. any way, feel free to ask for help with any issues you may encounter along the way. I am always happy to try to help diagnose whenever I can take time to visit the website... p.s. pulling the plug and pouring in a capfull of jaso is a great way to start a big job. it will extend the life of that upper and keep your compression thru the roof... Robert...
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