Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Husqvarna => Topic started by: phil1863 on January 11, 2018, 12:17:08 pm

Title: Husqvarna 445e....Piston ring Repair advice.
Post by: phil1863 on January 11, 2018, 12:17:08 pm
Last year my 445e chainsaw lost its compression.   :o.  I had not been used much, approx 4 times a year. Today I stripped the chain saw down so that I could see the cylinder, piston and ring.  I am only a novice here, so would really appreciate some advice.
I cant see any scouring in the cylinder and it all feels very smooth, so I think is ok. :)
However the piston ring is completely flush with the piston.  The piston ring does not want to move in its groove at all (possibly welded in place?).  Perhaps later I will try and tap it out using a hammer and small chisel.  Anyway that is the reason that I have no compression.
Can anyone help me with the following questions:
1. It seems likely that I should get a new piston and ring, because the old piston is also probably damaged, or would you try and get away with just replacing the ring (provided I can get the old one out)?  Please see attachment.
2. Should I get an husqvarna piston & ring or go for a cheaper (Chinese) make on the web?  Any suggestions as to where I should purchase these?
3. The gaskets look ok to me, but should I also as a matter of course replace those as well?

On a further note, I am of course worried that I might put it all back together only to find that it does exactly the same thing again.  The top of the piston does look like it has got very hot and that is the probable reason why the ring has contracted around the piston.  What do you think probably caused this?   I always tried to mix the correct oil ratio, if anything I may well have added to much oil...could that have caused this? I must admit that when I used the saw last just before it lost its compression I did have a feeling that the saw might have been running hot.   What other things might have caused this?  Should I consider getting the carb settings checked by a Husqvarna technician?

Thanks
Title: Re: Husqvarna 445e....Piston ring Repair advice.
Post by: deezlfan on January 11, 2018, 01:26:28 pm
NO NO NO! No hammer and chisel. It is stuck because of carbon build up not heat damage.

 First start soaking the ring with whatever solvent based parts cleaner you have. You will have to patiently soak the ring and give it time to loosen.  GENTLE tapping with a PLASTIC hammer or screwdriver handle. Tap soak tap soak tap soak. Do not pry on the ends of the ring. It will eventually come loose with gentle tapping.
Title: Re: Husqvarna 445e....Piston ring Repair advice.
Post by: deezlfan on January 11, 2018, 01:36:45 pm
There is nothing wrong with the piston or ring that you have. Get the ring freed up and gently remove the ring and clean the ring groove. Carefully reassemble the piston and ring making sure you put it back on right side up and the ring is not caught on the locating pin. Should be safe using the seal that is on the case already. You might want to put a TINY amount of Moto-Seal or similar product on the flange.
Title: Re: Husqvarna 445e....Piston ring Repair advice.
Post by: phil1863 on January 12, 2018, 07:18:47 am
Thank You deezlfan for your excellent  advice.  I had no idea that carbon build up could do this.

I will try what you suggest and let you know how it went.

Thanks so much for your help  :) :) :) :) :)
Title: Re: Husqvarna 445e....Piston ring Repair advice.
Post by: pete on January 12, 2018, 07:52:25 pm
Piston looks great as Deezlfan said soak it and soak it some more be gentle take your time  it all looks good
Title: Re: Husqvarna 445e....Piston ring Repair advice.
Post by: 3000 FPS on January 12, 2018, 09:58:56 pm
Yep Deezlfan has it all correct.    Good advice.
Title: Re: Husqvarna 445e....Piston ring Repair advice.
Post by: Cut4fun . on January 13, 2018, 08:14:53 am
Info is dead on like said. Only thing I will add. I am not a patient man. Never been able to reuse a ring when it has been stuck. So I always end up putting a new ring after cleaning the ring groove up. Test ring in groove and make sure it moves freely when done with groove.
Title: Re: Husqvarna 445e....Piston ring Repair advice.
Post by: deezlfan on January 13, 2018, 09:03:08 am
I may be projecting some of my frugality and tendency to be a little OCD when it comes to cleaning when I work. I have no objection to the suggestion of replacing the ring if you are already in there but I have had several successes just cleaning everything up. If you have one available it is cheap insurance.
Title: Re: Husqvarna 445e....Piston ring Repair advice.
Post by: phil1863 on January 17, 2018, 06:50:45 am
Hi guys, thank you so much for taking the time and effort to reply to my post.  Your all brilliant!!!

As for the ring, it is proving to be very obstinate, which I think is probably all part of the course.  I have been continuously soaking it in WD40 (some in a can cap and leaving the piston in to soak day & night).  Every few hours when I can, I tap the ring/piston with the handle of a screwdriver.  I dont think it has moved much.....the ring is still mainly flat to the surface of the piston.  I have also been spraying it with Shock & Unlock from Halfords.

To be perfectly honest I am not sure if I would have the confidence of using this same ring again.  It probably has not done it any good being stuck in this position for well  over 6 months.  Perhaps I should invest in a new piston ring anyway?  I will continue soaking & tapping it for a while longer in case it pops out, failing that I guess I will have to somehow lever it out.

One other thought, would heating it in anyway help free it?

Sorry guys, one more question...where would you recommend buying a piston ring, would you go direct to Husqvarna or maybe something like the link below?
[url][https://www.ebay.co.uk/itm/Piston-Ring-fit-HUSQVARNA-445-445-e-537401101-/400328608722/url]

Again thank you very much for all your fantastic help :) :) :) :) :)
Title: Re: Husqvarna 445e....Piston ring Repair advice.
Post by: Cut4fun . on January 17, 2018, 07:29:28 am
Are you in US?  Caber rings are good to use. Northwood saw carries them right here in US.  http://northwoodsaw.com/index.php?l=product_list&c=78

IMO wd40 isnt going to touch it. The other I dont know what it is.

Al uses Kroil and heat  http://www.kanolabs.com/google/?gclid=EAIaIQobChMI28SInP_e2AIVxbrACh1GNAN1EAAYAiAAEgIEQ_D_BwE.
Swears by it. I had to have him do a hard to find piston for me because I had lost my patience.

I have been using a different way to get rid of carbon and you might try it on yours. Soak top past rings in Berrymans B12.  https://www.berrymanproducts.com/products/gasoline/b-12-chemtool-carburetor-fuel-system-and-injector-cleaner/
Title: Re: Husqvarna 445e....Piston ring Repair advice.
Post by: phil1863 on January 17, 2018, 11:35:11 am
Thanks Cut4fun
I am in the UK. 
I asked at a local husqvarna  dealer about the ring, and he quoted 10 pounds. I know that I can get it cheaper on the web, but I am assuming that it is a genuine husqvarna part, so might be my best option.
Kroi sounds good stuff, but haven't been able to find anywhere in the UK that stokes it for a reasonable price.

You mentioned Berrymans B12 reminded me that I had some carb cleaner in the garage that I bought last year, so I thought that I would give that a go.  So now I am soaking it in that.

I have noticed that one end of the ring has lifted a little bit, almost to the position that I might be able to get my nail under it  I am trying to be gentle, because I dont want to damage anything, especially the piston.
I am not so bothered about damaging the ring because I can easily replace that, but I want to try and avoid any damage to the piston.

I will continue tapping and soaking for a few more days, just in case it does free up.

Thanks again
Title: Re: Husqvarna 445e....Piston ring Repair advice.
Post by: Cut4fun . on January 17, 2018, 12:46:25 pm
UK yep use the greek seller on ebay then. Caber is good to use though. If the price is way cheaper for you.
Title: Re: Husqvarna 445e....Piston ring Repair advice.
Post by: phil1863 on January 21, 2018, 08:01:33 am
Well I gave it a week of tapping/soaking, but I am sorry to say my patience has run out.  It had lifted one edge very slightly, so i got a small screwdriver under it and snapped the ring.  I had to lever the ring off in small chunks because it was so caked in.  I have cleaned out the slit using a bit of the broken ring ( I hope that I have not been too violent with it).  Someone suggested that I use oven cleaner to help clean the slit , so I will get some today.  I have ordered a new ring which should come early next week.  In the end I bought it from my local Husqvarna dealer ( I chickened out and wanted to make sure that I got the right replacement , it was only a few quid more).

deezlfan suggested that I might put a little Moto-Seal on the flange.  I was going to order some of this on ebay.....
https://www.ebay.co.uk/itm/Hylomar-Universal-Blue-Gasket-Jointing-Compound-Sealant-40g-Fuel-Resistant/281159734843?epid=1688381898&hash=item41766d163b:g:4kkAAOxyJX9SIOcA
Would that be ok to use?

Thanks again for all your help.


Title: Re: Husqvarna 445e....Piston ring Repair advice.
Post by: Cut4fun . on January 21, 2018, 09:17:35 am
I fold over emery cloth folded to clean the groove with too. Make sure to flush good when done. 

I break almost every stuck ring too. No biggie ;)
Title: Re: Husqvarna 445e....Piston ring Repair advice.
Post by: Cut4fun . on January 21, 2018, 09:20:56 am
I dont know what that blue is.  This is the stuff stihl uses on theirs.  Elring Dirko HT Red

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313.TR0.TRC0.H0.TRS5&_nkw=Elring+Dirko+HT+Red+Silicone+Sealant+&_sacat=0
Title: Re: Husqvarna 445e....Piston ring Repair advice.
Post by: phil1863 on January 21, 2018, 09:48:27 am
Thanks cut4fun.  I have ordered the Dirko HT red.  I will also use some emery cloth.

Thank You :) :) :) :)
Title: Re: Husqvarna 445e....Piston ring Repair advice.
Post by: farmboy on January 21, 2018, 10:44:50 pm
I fold over emery cloth folded to clean the groove with too. Make sure to flush good when done. 

I break almost every stuck ring too. No biggie ;)

I just go ahead and break them and I'm a patient man.  Going to replace it anyway.
Shep
Title: Re: Husqvarna 445e....Piston ring Repair advice.
Post by: phil1863 on February 18, 2018, 07:54:42 am
I have been a little slow here, but I had problems getting the dirko HT delivered and I have only just re-built the chain saw with the new ring installed. I used a very small amount of Dirko  on the seal.
I have not tried to start it yet, because I would really like some advice to help prevent this problem from recurring.   I really appreciate the help that I am receiving on this forum. Thank You to all!!!!

First of all I must point out that I tried doing a compression test yesterday and unfortunately I was very disappointed in the result.  It measured a 100psi which I believe is not great???? :'( :'( :'( :'( :'(

Could this be because it needs to bed in before I do this test or could it be another problem?

Clutching at straws but it might be the decompression valve?  Originally when I discovered about the compression problem(before the new ring fix)  I did check the valve by putting soapy  water on it.  Unfortunately i did not dry this off and the button had seized (rusting while I was trying to fix the saw)
I soaked it in some oil and had to lightly tap to free it.  I think that it is working ok, but my inexperiance might prove me wrong!!!

Moving on, why did I get this problem in the first place?  I have been told that it was probably due to old fuel (which possible might be the case)?
Are there other reasons that this might occur....e.g. carb settings or to much oil in the mix?  I dont want to try and start it until I know a little bit more.

I did make a stupid mistake early last year, in that I placed chain oil in the fuel tank.  I immediately saw my mistake and I emptied the tank and washed it out with more fuel.  But is it possible that this may have caused the problem later?
I checked the fuel filter and have posted a picture of it.  To me it looks ok, but again should I replace it.

 ;D ;D ;D ;DYour probably having a good laugh at all the mistakes that I appear to be making.....    To be honest I only use the saw 2/3 times a year....perhaps i simply need more practise :) :)

Sorry for the long message and thank you so much for your valuable help.
Title: Re: Husqvarna 445e....Piston ring Repair advice.
Post by: phil1863 on June 18, 2018, 04:12:09 pm
Just a quick thanks for the great help that you guys gave me to help me fix my husqvarna.  To be perfectly honest after replacing the piston ring (and the low compression) I did'nt have a lot of confidence that the saw would work.  Last weekend was the first time since doing the repair that I needed to cut some wood and before that I did'nt think that the saw would be worth the effort of trying to start.  I thought that anyway that I would have to use my other chainsaw to cut the wood up.  Well I gave the husky a go and to my great surprise it went like a dream!!!!  :) :) :) :) :)...it worked perfectly and had lots of power.  I hav'nt done another compression test, and I dont think that I need to bother now (IT WORKS BEAUTIFULLY).  I think that the ring probably needed to bed itself in???  The saw now works as well as it ever has.

I spent all day today cutting logs with it....and will probably do the same tomorrow.     I am sooooooo  pleased!!!!!!

Without your help I'm not sure that I would have had the knowledge to attempt the fix.......so thank you guys (cut4Fun,farmboy, etc)

I will now make sure that I never use old fuel ever again in my chainsaws.
Thanks Again