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#Post#: 74649--------------------------------------------------
Breaking loose a stuck piston
By: Al Smith Date: November 28, 2016, 4:05 pm
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The subject is a Partner P100 super,stuck tight .Old trick I
learned a long time ago ,knock the center out of a spark plug
and attach a grease zert ,.Several ways to do that .
One way which is what I did was use a die grinder with a cut off
wheel and grind the metal right above the hex where you put the
wrench on .Grind off the ground electrode .By tapping with a
small hammer in and out the center electrode and insulator will
pop out .Then use a 1/4" pipe tap and thread the inside of the
plug shell .Then install a 1/4" pipe to 1/8" pipe reducing
bushing then a 1/8" pipe thread zert .Another is to braze a
1/8" pipe coupling then screw in a zert .
By pumping grease or oil though the plug hole you can move about
any piston .Usually if you move it a fraction of an inch it will
pull right out .Not so on this one .I had to pump grease in it
until it came out the exhaust port .Then I had to rock it
further by using a brass rod on the fly wheel .It was really
stuck .
The cylinder and the piston believe it or not are clean,I can
save both of them ,needs rings of course .The mains are shot
.I'm not so sure if this saw might have been under water at one
time although the crank pin needle bearings seem to be okay .
#Post#: 74652--------------------------------------------------
Re: Breaking loose a stuck piston
By: 3000 FPS Date: November 28, 2016, 6:11 pm
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Good Info Al thanks. That sounds like it was a real bear to
get out.
#Post#: 74654--------------------------------------------------
Re: Breaking loose a stuck piston
By: 1manband Date: November 29, 2016, 3:42 pm
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heard of the technique........but have never heard of anyone who
tried it. nicely done!
were the ring(s) broke after it broke free?
#Post#: 74655--------------------------------------------------
Re: Breaking loose a stuck piston
By: dannyupsolate Date: November 29, 2016, 6:28 pm
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When Al Smith speaks newbys better listen ;D
#Post#: 74658--------------------------------------------------
Re: Breaking loose a stuck piston
By: Al Smith Date: November 29, 2016, 7:52 pm
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The rings were just rusted fast .I wouldn't be surprised if they
might be okay .Never the less I'll use new rings on the
assembly.
The spark plug was missing ,I ran a tap through it to clean the
threads .Evidently for whatever reason it had just rusted up
from sitting in some damp place .It didn't have any sign of
galvanic reaction so it wasn't on concrete .
I have used the plug/grease gun method on a lot of stuck engines
.The last I did was a 300 cubic inch Ford before this saw engine
.That one was a hoot .I had all 6 cylinders full of penetrating
oil for about a week,knocked it loose with a grease gun full of
oil then rolled the engine with a big wrench .Then lost my
concentration and rolled it with the starter forgetting all the
oil in the cylinders and drowned myself with oil ,duh .When I
got it started and came out of the woods my wife came running
out of the house shouting "the trucks on fire ".That thing blew
blue smoke for at least 10 minutes .So much for the idea of
drowning a plug with too much oil in the mix ,never fouled a one
.
#Post#: 74660--------------------------------------------------
Re: Breaking loose a stuck piston
By: Al Smith Date: November 29, 2016, 7:59 pm
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Problem with old saws that get banished to the shelf is you
never know exactly why they got put there in the first place
.Sometimes you can tell but more times than not you'll never
know .This one it could be a bad main bearing ,bad ignition or a
host of other things .I might or might not figure it out once I
dig into it .
#Post#: 74668--------------------------------------------------
Re: Breaking loose a stuck piston
By: RoyM Date: November 30, 2016, 6:56 pm
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;D I was just visualizing you leaning over that Ford when you
hit the starter. Too funny.
#Post#: 74669--------------------------------------------------
Re: Breaking loose a stuck piston
By: Al Smith Date: November 30, 2016, 7:38 pm
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I looked like an oil field worker .Mrs Smith was amused but not
surprised .
#Post#: 74765--------------------------------------------------
Re: Breaking loose a stuck piston
By: trail twister Date: December 7, 2016, 10:41 am
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OK I have to ask, with the ford 6 banger how did you know what
pistons were on the down stroke and which were on the up stroke?
;D Al
#Post#: 74771--------------------------------------------------
Re: Breaking loose a stuck piston
By: Al Smith Date: December 7, 2016, 3:55 pm
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Doesn't make any difference.Filled the cylinders with oil,let it
soak .Used another plug with an air chuck to find out which ones
had the valves closed .
Now on a large cylinder on a 300 it took forever and a day to
pump enough oil in to move the thing a 1/4 of an inch .56 MM
chainsaw it moves fairly quick .
I found a cylinder that was coming up on compression about half
way up .That way it would exert more rotational power having
the crank pin at 90 degrees rotation .On the saw I unbolted the
cylinder and just raised the cylinder rather than try to rotate
the crankshaft .I didn't know if it had bearing damage which it
in fact did have .If the crank was hung tight I could have
broken something .
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