Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Stihl => Topic started by: SDB777 on September 05, 2015, 11:01:24 am

Title: Top of piston has....
Post by: SDB777 on September 05, 2015, 11:01:24 am
A LOT of black-ish looking crud on top of the piston inside my Stihl 064, but the side of the piston is still looking really good(pulled muffler) - could use some new rings shortly.

Question:  Is there a way to remove the 'crud' without taking the top end off or having the crud ruin the cylinder wall?


Scott
Title: Re: Top of piston has....
Post by: RoyM on September 05, 2015, 11:55:22 am
What oil are you using and at what mix ratio? I suggest 40:1, I run mine at 50:1 but don't want to start any arguments, and run 'er hard to get it up to proper operating temperature.
Title: Re: Top of piston has....
Post by: SDB777 on September 05, 2015, 07:59:41 pm
What oil are you using and at what mix ratio? I suggest 40:1, I run mine at 50:1 but don't want to start any arguments, and run 'er hard to get it up to proper operating temperature.

I've run 35:1 while milling....and I know it has been run hard, probably more then warm.  The crud is still on top of the piston.



Scott (no sleep for a few) B
Title: Re: Top of piston has....
Post by: mdavlee . on September 05, 2015, 09:08:01 pm
Stihl used to have a hook to scrape carbon off. My grandpa has one in his 028 case.
Title: Re: Top of piston has....
Post by: farmboy on September 05, 2015, 09:33:01 pm
Stihl has decarboning solution.  CRC too.  I justpull the cyl. and clean.
Shep
Title: Re: Top of piston has....
Post by: JohnG28 on September 06, 2015, 10:01:44 pm
Pull the cylinder to clean it up and throw in the new rings while you're at it.  ;)
Title: Re: Top of piston has....
Post by: jeff.lary on September 07, 2015, 06:07:41 pm
Yes I agree with the above if you want to put in a new set of rings well....there is no time like the present. Pull the top clean off the crud change the rings check the squish while you're in there too.
  I have taken my pistons out and put them on my 6" wire wheel to get the hardest stuff off with no ill effects at all. They claim loose carbon or fixed for that matter can do it's own damage to the cylinder if left un-checked. Good luck
Title: Re: Top of piston has....
Post by: Cut4fun . on September 07, 2015, 07:11:40 pm
Yep I have seen a few saws with carbon scoring. Looks bad but still ran fine and piston cylinder was fine. Usually cleans right up.
Title: Re: Top of piston has....
Post by: Al Smith on September 07, 2015, 08:39:51 pm
It isn'really the oil mix ratio more so it's set a tad rich  wth a restricted exhaust .

Take for example the old outboard boat motors .If you ran at trooling speeds for extended periods they would carbon up .Simple fix,lean them out and run the snot out of them .Richen up so they would run at trooling speeds and go catch walleye--or at least try . ;)
Title: Re: Top of piston has....
Post by: joe_indi on September 08, 2015, 11:51:17 am
If you dont mind some 'Witch Doctor' treatment  mix coconut oil with your 2 stroke oil 1:1. Use this mix for a couple of tankfuls at 25:1 once in a way. The coconut oil will gradually get rid of the crud, very slowly.
Right now I am adding Pidilite's Cyclo Motor flush at 1:1 with coconut oil.
I add 5% of this mix with the fuel(2 stroke oil as usual)
The motor flush and coconut oil mix cleans up everything in its path right from the fuel tank onwards.
I have been using this for more than two years on the saws that come in for service.
Only good things have happened so far.
Title: Re: Top of piston has....
Post by: Al Smith on September 09, 2015, 05:27:19 am
About the only saw engines I have found with high carbon build up are those the oiling system are open to the crankcase such as impulse operated McCullochs .That's because eventualy they all leak a little bit and suck chain oil into the cylinder.You can't totally burn chain oil .

As far as heavy mix ratios no kidding I've torn down old saws I know had been ran on 16 to one using motor oil and they were virtually carbon free .They had sat on a barn floor for 30 years to boot .
Title: Re: Top of piston has....
Post by: 660magnum on September 09, 2015, 11:01:04 am
+1
Title: Re: Top of piston has....
Post by: SDB777 on September 11, 2015, 08:26:52 am
Rings are showing delivery today....good thing.
Wife wants to re-do the floor in the spare room from carpet to tile this weekend....bad for me, good for the house and her thing.

I'll let you decide what you think will happen.



Was wondering what size solder folks are using to check squish?  I have some really thin stuff(.015), and I'm thinking that would be far too thin to use.  What is a 'good squish' for the 064?(this isn't a race saw, just a tired workhorse saw)



Scott (yes, I'll be ripping out carpet) B
Title: Re: Top of piston has....
Post by: aclarke on September 11, 2015, 03:53:03 pm
   Low 20 thousandths should be fine with stock compression
Title: Re: Top of piston has....
Post by: Al Smith on September 11, 2015, 09:18:59 pm
Don't feel so bad about not being able to work on the saw in a timely manner .I've had some it took me months to finish .
Title: Re: Top of piston has....
Post by: JohnG28 on September 12, 2015, 07:58:54 am
Better to use rosin core solder as it's a little softer and easier to compress. It's the kind made for soldering electronics. Don't use the acid core or solid solder, the acid is bad in an engine and the solid core is usually too hard to squish down.
Title: Re: Top of piston has....
Post by: mdavlee . on September 12, 2015, 09:10:36 am
Plastigauge also works. The yellow is .040" thick. Will go down to .010".
Title: Re: Top of piston has....
Post by: SDB777 on September 13, 2015, 01:34:11 pm
I hate painting!
I hate putting tile on a floor!

If you guessed, I wouldn't see a chainsaw this weekend, you win!  She had me slaving away....and now that I'm done, I'm too sore to bend, stand, walk, stretch, think.....I have 18hrs remaining to 'recharge' before going back to work(which at this point will feel like a vacation).


Thanks for the 'squish and solder recommends'!!!!!



Photo's show everyone how I can pay for repairing these old crappy chainsaws....and because photo's are fun.

(http://i29.photobucket.com/albums/c271/SDB777/Duck%20Calls/DSC01195_zpstqxm2cx4.jpg) (http://s29.photobucket.com/user/SDB777/media/Duck%20Calls/DSC01195_zpstqxm2cx4.jpg.html)

(http://i29.photobucket.com/albums/c271/SDB777/Duck%20Calls/DSC01194_zpsdxrbx1sb.jpg) (http://s29.photobucket.com/user/SDB777/media/Duck%20Calls/DSC01194_zpsdxrbx1sb.jpg.html)




Scott (quack, quack, BANG) B
Title: Re: Top of piston has....
Post by: Cut4fun . on September 13, 2015, 02:14:13 pm
Very cool on those duck calls. Nice
Title: Re: Top of piston has....
Post by: SDB777 on September 24, 2015, 09:42:31 pm
After the lawn is mowed, groceries....well groceried and put away, I get to pull a saw apart tomorrow.

Figure a good old fashioned wire brush is good enough to use on the top of the piston....




Someone mentioned pulling oil into the cylinder....how does a person go about checking that?



Scott
Title: Re: Top of piston has....
Post by: David Young on September 25, 2015, 11:38:22 am
Don't feel so bad about not being able to work on the saw in a timely manner .I've had some it took me months to finish .

got ya beat Al, some of mine have sat for years. 

as for carbon I use a razor blade with a raking angle and a little pressure.  some will remain but will get the bulk of it.  I use compressed air or a rag or rinse in old gas then a wipe or blast of air to get the piston clean

Title: Re: Top of piston has....
Post by: Cut4fun . on September 25, 2015, 02:29:31 pm
Don't feel so bad about not being able to work on the saw in a timely manner .I've had some it took me months to finish .

got ya beat Al, some of mine have sat for years. 




Got a few projects going on forever myself right now.  Just hard to get into them when I already have same saws running.

Now if it is someone else's saw I get it right back out there.