Service & Maintenance Question
Best Answer
Answer
- posted December 16, 2011 by Linden OPE
- Permalink
- Show/Hide Replies
The chainsaw basically needs 3 things to start, fuel, spark and compression. From what you've described you may have narrowed it down. The next thing I would check is the compression level. It should be around 115-120 psi. It's a fairly simple test that your local Husqvarna dealer can help you perform. Hope this helps. I'd be interested in hearing what you find out.
Update: I just picked my saw up from the repair shop. The mechanic stated the saw had very low compression due to a "Stuck Piston Ring".
The "Stuck Piston Ring had heavy carbon that stuck it." He went on to state that it was the result of running either very old fuel/oil mix or using the incorrect oil or mix.
Now I know my fuel mix was correct and it ran another 2 cycle engine fine. The mix was months old but had StaBil in it. I have never heard of a "Stuck Piston Ring". If it was "Stuck" why would the compression drop? Wouldn't it cause more interference to the piston? I have only heard of broken piston rings prior to this instance.
This saw replaced a Stihl that I used for over 15 years without any major issues. I also have owned 2 cycle string trimmers for well over 10 years without any engine issues. I am questioning the quality of this Husqvarna saw now given the low number of hours on it.
- posted February 27, 2012 by Linden OPE
- Permalink
It is becoming more and more common these days to see carbon build up on the cylinder top, the piston rings and the exhaust port of the small engines. This is generally caused by using older gas. With all the ethynol being put in to the gas these days the gas doesn't last nearly as long as it used to, even with a stabilizer. I would recommend only purchasing enough gas that can be used within a months time, with a stabilizer maybe two months. The other thing you can do to prolong the life of your gas is to make sure it's stored in an air tight container.
As far as the question about a "stuck" ring affecting the compression, when a ring is stuck it can't expand and contract as the piston moves up and down. As the piston moves up the ring expands out to the wall of the cylinder, which is what builds up the pressure. With a ring that is stuck or broken this can't happen.
This post is a couple of months after your last post, hopefully you've had better success with your saw.
- posted July 17, 2013 by John Canton
- Permalink
I am experiencing the same issue with my 445 Rancher. I run 50:1 premixed Husqvarna brand fuel that is sold in a can. I used the saw for ten minutes on Friday with no issues. I about destroyed my shoulder on sunday trying to get it started.
The chainsaw basically needs 3 things to start, fuel, spark and compression. From what you've described you may have narrowed it down. The next thing I would check is the compression level. It should be around 115-120 psi. It's a fairly simple test that your local Husqvarna dealer can help you perform. Hope this helps. I'd be interested in hearing what you find out.