D eez: What do you think has happened DonyBoy73?
Anyone else have any ideas?
What and where does the contact occur that causes scoring on the piston;
below the ring?
BeaudreauBell1141 (1Year ago) suggests engine is running to lean and in
turn exhaust gases get hotter and then the aluminum piston goes(I guess he
means it gets scored) but he also kind of mentions that the “PISTON RING”
often gets seized in its groove.
"I think" this “Seized Piston Ring” scenario makes the most likely cause
because if ring is seized in its groove, (likely due to carbon buildup) it
stops the piston from being centered and when ring wears away on part of
its area the piston will rub on the cylinder wall along with metal shavings
and carbon. I think this is the likely cause because I recently took apart
a Poulan where all the evidence pointed to the Seized Piston Ring in its
Adam Luna: I have the 346xp but after first 2 logs I cut I start getting some oil burn
smoke on my chain and then the chain goes dull and lots of smoke coming
from the chain bar. What could be my problem?
Shaun Victor: I just purchased a used Stihl 026 and its running right at 140PSI and it
has no scoring whatsoever and it runs great.140 is not really a low
reading.When you pushed the piston around inside the cylinder that was
weird.That top end is not going to live long,thats for sure.
You should pull it down and see if the cylinder is worth salvaging and
maybe get away with a new piston and ring.
Would like to know how it all works out.
donyboy73: @xxtruckin93xx thanks dude, do u have a vid of ur 12 hp briggs problem?
petr korolesov: техника всех времен
donyboy73: SOUNDS LIKE THAT IS YOUR PROBLEM
cyrus romer: I have a 345 chainsaw and it won't start and there is scoring on the intake
side but I noticed that its missing a bolt underneath it could that be the
problem why it won't start
daand12: @donyboy73 hmm yes there was space between the Cylinder and piston. The
same as on this saw
donyboy73: @Liamautomechanic i just did the 55 with a chinese top end
MrRmh3481: Another great vid DB. Husky/elux had some labor problems when they wanted
to build the small saws to sell in N America via Poulan in Ohio. That one
looks just plain worn out. 346xp OEM top end is $280 or aftermarket is $120
out of uk.
Liamautomechanic: them huskys are bullit proof, grand saw, very favoured in ireland, by
foresty workers, party,
Xxpoison99xX: I put an expansion chamber on my saw off an 83 rm80 and it runs waaaaaay
donyboy73: very possible
donyboy73: @daand12 that's what hapenned to ur scooter?
cyrus romer: I have a super xl homelite chainsaw and the piston has scoring on the
bottom side of the piston and the piston is loose in the case is that bad
but it runs fine
mooch1441: Ok I just thought if I did sell it I would notify the buyer way before
hand. I have two other older lawnboys and have also thought about using it
for parts. What would you suggest?
donyboy73: @MrRmh3481 would be worth the aftermarket kit
TheDurnans: I use 87 octane non ethanol petrol and I mix it a little rich. I use a 2.5
gallon mix jug and mix it to 2 gallons of gas. I've seen saws fry before
while using the "correct" 50:1 mix, so I'm a little hesitant to run a true
50:1. To be honest, i really don't know how to properly adjust the carbs on
one of these saws. I'd be afraid to lean it out to much and burn it up that
Carl Bowen: was he trying to make crisps haha
niper99: @Smallgasengine1 ahh what!!!
spelunkerd: Please forgive me for an unrelated question. If you need to sit your (two
stroke) chainsaw for more than a few months, is it appropriate to use gas
stabilizer mixed with the gas/oil mixture? How long can you leave the
mixture of gas and oil in a tank before you are better off sending it to
dalvord: I'm bugging you again to wear hearing protection, especially when running
BeaudreauBell1141: The reason it still runs is because the ring didn't seize in the piston!
I've dealt mostly with larger 2 strokes with iron cylinder liners and this
normally happens when the engine is run too lean. The oils are so much
better now a days and I know that most people tend to over mix the oil.
When you run one lean, the exhaust gets so damn hot and the first thing to
go is the Aluminum piston and it is very seldom that the ring doesn't get
seized in the groove! I have often just freed the ring.
carrick64231: Saw looks brand new-wonder how the piston got scored?
Ryan Gebert: How much psi should a tecumseh lawnmower have?
Liamautomechanic: what about a chinees top kit, ie, barell and piston, ring, kit,?????????
check compression, hot and cold,???????????see what the out come,is,
TheDurnans: I just bought a 346XP ETech - not my choice to have the cat muffler, but
was told all new 346s are cat muffled now. Mine runs hotter than a pistol
and I haven't adjusted any of the screws on it since I bought it a little
over a month ago. When it's good and hot, it doesn't like to stay running
and is very hard to start. You can see the heat come off this saw after
cutting oak when it's 70+ outside. I'm afraid I'm going to fry my saw! I'm
running the XP oil as well.
stlouissux9119: Shocked me too!
Liamautomechanic: @donyboy73 how did it turn out,??????????????
donyboy73: @Liamautomechanic very good, i will post the video soon
donyboy73: @carrick64231 probably the owners fault
donyboy73: should be
tribulation138: I also came across saws even though they have pretty good pistons and jugs.
There compression was lower than 150 but ran well. Some saws have different
size base gaskets effecting compression.
Smallgasengine1: cylinder head must be loose
Bubaaak: Why is important to hold throttle open during the test ?
donyboy73: @dalvord i will get a pair of ear muffs, LOL
classicoutboards: I'd just run it till it blows
donyboy73: not quite all the power it should have
Liamautomechanic: the donkey is well, worn out, surprising, it kicks out 140 psi, could be
the oil in the mix, giving a false reading, the oil mix, would seal the
scores, when cold, it would be a bitch, to start when hot, u should try a
compression reading when hot,??????????just a thought, good vid dony,
Patriot36: That was an excellent short class! I'm completely amazed at how well that
saw runs after seeing the piston knock back and forth! LOL...credit to
husky for a tough product. Seems that someone may have run it too hot.
cyrus romer: I have a 345 that won't start it has spark and good compression but there
is scoring on the intake Side but none on the exhaust side I noticed a bolt
missing on the underneath the motor could that be the problem not enough
mooch1441: Donyboy I have a older 2 cycle lawnboy and the piston is very scored. It
has about 90 PSI but still runs ok. I was thinking about selling it before
i saw the scoring. Do you think I should still sell it?
highcountrytimber: With what is going on interally 140 Psi is suprise for sure. I have a
couple old saws that feel soft to the pull and are wore and still run on
120PSI. PSI is not a real good indicator if the engine is bad. Score looks
like it was a manufactures defectice wrist pin,these husky are know to have
some of the wrist pins being bad.
daand12: That saw just needs a new Cylinder. That will not last long with that
piston and cylinder.
donyboy73: i know but i just don't have time to keep up
Ron Swanson: would something like 140psi be alright for a ms660?
bradsengine: Did the saw have its normal power??
donyboy73: @Bubaaak apparently to let more air in
donyboy73: I prefer not selling things with know defects
xxtruckin93xx: you cut those so thin you could make drink holder lol
Husqvarna 346xp Chainsaw Scored Piston Compression Test & Startup4.9
out of 5