(DIR) Return Create A Forum - Home
---------------------------------------------------------
Chainsaw Repair
(HTM) https://chainsawrepair.createaforum.com
---------------------------------------------------------
*****************************************************
(DIR) Return to: Stihl
*****************************************************
#Post#: 4792--------------------------------------------------
Re: Stihl 084 AV dies at idle
By: Al Smith Date: November 10, 2011, 9:28 am
---------------------------------------------------------
You could possibley have a leak in the impulse line but usually
if so it won't run long in high speed .On the idle circuit just
in what the fuel chamber holds on a saw the size of an 038 it
will idle 10 minutes with a dry tank .You almost think it is
going to run forever .
#Post#: 4793--------------------------------------------------
Re: Stihl 084 AV dies at idle
By: mike84c Date: November 10, 2011, 9:40 am
---------------------------------------------------------
Yea, I tend to agree with that. I replaced the impulse line
with a piece of clear tygon, and it still is the same. I'm
starting to think it may not be the carb, as I was running in on
the ground with the air filter off, and kept opening up the low
speed needle, as I kept goosing the throttle to keep it going.
I could get the low speed condition so rich that gas droplets
were spraying out the carb intake, which means to me, the low
speed circuits are functioning. I'm thinking about pulling the
cylinder off and seeing what I see. what compression should
this saw have cold? anyone know?
thanks
Mike
#Post#: 4794--------------------------------------------------
Re: Stihl 084 AV dies at idle
By: Cut4fun Date: November 10, 2011, 12:18 pm
---------------------------------------------------------
My good running stock one with a lot of time on it was holding
145psi last time I checked it before selling. Keep pulling till
the needle doesn't move up anymore on gauge to check.
#Post#: 4798--------------------------------------------------
Re: Stihl 084 AV dies at idle
By: Al Smith Date: November 10, 2011, 12:50 pm
---------------------------------------------------------
Low comp won't make it die on the vine .I wouldn't worry too
much about it unless you can pull it over easily without the
decomp .Even then keep in mind that's a static reading which
could jump quite a bit once the engine is running
That thing just isn't getting fuel through the low speed jet for
some reason .
As far as the carb ,I've never worked on that model so I know
little of nothing about its' praticuler whims and where fors
.I've had carbs run with just the low speed but never had one
the wouldn't suck gas though the low speed .--Unless that thing
has a bolted butterfly with a slot that came loose .If so on
some carbs if that slot does not align with the fixed jet
/nozzle they won't idle .
#Post#: 4800--------------------------------------------------
Re: Stihl 084 AV dies at idle
By: mike84c Date: November 10, 2011, 12:56 pm
---------------------------------------------------------
I'll look at that and see if the holes in the carb bore are
plugged off by the throttle plate, although I have already put
two layers of tape on the idle screw to increase the idle, and
stuck a small screwdriver under the throttle to increase the
idle, and in all cases, she dies just the same
#Post#: 4803--------------------------------------------------
Re: Stihl 084 AV dies at idle
By: man of stihl Date: November 10, 2011, 5:21 pm
---------------------------------------------------------
service manual says. Engine stalls at idle speed, but operates
normally at full throttle; oil seals leaking or manifold
leaking. I hate to say it but it sounds like you have an air
leak. If the new carb is giving you the same symptoms..... That
365 poulan i had was doing the same thing. would run wide open
but wouldn't idle. It ended up needing bearings and seals.
#Post#: 4804--------------------------------------------------
Re: Stihl 084 AV dies at idle
By: mike84c Date: November 10, 2011, 5:32 pm
---------------------------------------------------------
that sort of makes sense. I will do a pressure test and see
where its leaking, unfortunately I have to make up an exhaust
and intake cover. will let you know what I find
Mike
#Post#: 4808--------------------------------------------------
Re: Stihl 084 AV dies at idle
By: w8ye Date: November 10, 2011, 8:20 pm
---------------------------------------------------------
This statement by you . . . .
"I'm starting to think it may not be the carb, as I was running
in on the ground with the air filter off, and kept opening up
the low speed needle, as I kept goosing the throttle to keep it
going. I could get the low speed condition so rich that gas
droplets were spraying out the carb intake, which means to me,
the low speed circuits are functioning."
Makes me think you have seal or other crankcase pressure
integrity problems if the intake side of your piston is not
trashed?
I've had carbs with the intake circuit plugged and I could never
get any droplets spitting out the carb from the low side.
#Post#: 4813--------------------------------------------------
Re: Stihl 084 AV dies at idle
By: Al Smith Date: November 11, 2011, 6:21 am
---------------------------------------------------------
Usually they will idle with a seal out but they often won't with
a tear in the boot .
What's with that tape on the low speed screw ? If that thing is
sucking air through a wibbley woobley screw I doubt it would
work too well .
#Post#: 4822--------------------------------------------------
Re: Stihl 084 AV dies at idle
By: mike84c Date: November 11, 2011, 7:37 pm
---------------------------------------------------------
The tape on the throttle screw was just an idea by one of the
forum to increase the dia of the throttle screw to hold the
butterfly open more, it didn't help. I ran a pressure test on
the engine. sealed up the carb side with a piece of inner tube
between the carb and manifold, sealed up the exhaust side with a
piece of inner tube between the exhaust and cylinder. clamped
the impulse line, and installed my leak down tester in the spark
plug hole. Pressurized to 10 psi, and it held rock solid. I
pulled the flywheel (what a pain it the butt, I guess its never
been off), and pulled the cluch and bar oil drive. I sprayed
both seals down with soapy water. No leaks, and as I said, it
held 10 psi rock solid. I also hooked up my vacuum pump, and
pulled a vacuum, and it held that also. There is no play in
either the clutch side bearing or the flywheel side bearing.
Didn't put a dial indicator on it, but as I said, absolutely no
play......So I'm guessing its not a crankcase or seal leak. Not
sure where the manifold leak would show up, but I'm thinking its
not it. Yikes.... I'm not sure where else to look. Anybody?
thanks
Mike
*****************************************************
(DIR) Previous Page
(DIR) Next Page