Stihl 084 AV Needs a Little Help

[Wood Doctor]

My good logger friend asked that I help him out with his Stihl 084 AV that he's been using for quite some time. Two things are now wrong and need attention:

(1) The saw starts and runs but idles much too fast (about 4,500 RPM), so the chain runs constantly and that's dangerous. We all know that. I've tried adjusting the idle screw and it has practically no bearing on the idle speed, even when the low speed carb setting is correct. I checked the throttle linkage, the fuel filter, and cleaned the air filter. All are in good shape. Regardless, the engine still loves to purr along at a 4,500-RPM idle or just plain die altogether when I change the low-speed set screw.

(2) The saw throws too much bar oil, so that needs to be cut back. It's a mess to use. I see no easy means of changing the bar oil flow. How do I cut that back about 30%? Is there an adjusting screw or knob somewhere? Most Stihl saws have an easy way of adjusting oil flow, but I can't find one on this model.

I would really like to save this saw for him because other than these two problems, this 084 AV seems to be in very good shape. Please advise and thanks in advance.

 

[rupedoggy]

You have an air leak and will damage the saw if you keep messing with it that way. Repair
The oil pump is adjustable but it is complicated. Get the owners manual and a repair guide and follow the instructions.

 

[gink595]

I agree, there is an air leak somewhere. I just completely rebuilt an 084 from top to bottom. It had a bad impulse line that seized it the first time so the guy had someone put a new piston in it and did the same thing... I'd start looking at the impulse line first and then fuel line and so forth. Check throttle shaft for excessive play could be sucking air there also.


Bottom of the oiler should have a adjuster.

 

[mdavlee]

Do the 084s have the manual override for the oiler? I thought the ones I ran did.

 

[Wood Doctor]

Do the 084s have the manual override for the oiler? I thought the ones I ran did.

This one has a manual pumper to the left of the throttle trigger, but I assume that is for adding more oil when you need it. What I am trying to do is cut it back. Seems like it's running with the manual oiler pressed down. However, I checked that also, and it seems to be OK.

If it has a manual override, I can't find it anywhere. Stihl also does not supply a PDF download for an 084 AV Owner's Manual. Not sure why. :msp_sad:

 

[mdavlee]

I was thinking maybe that button was hung open if it's dumping a huge amount of oil out.

 

[smilin possum]

I have to agree with the guys on all of the above. DON'T run that thing anymore or you are asking for big time trouble. An air leak will kill it. Right now all it's going to take to fix it is a set of seals keep running it and it'll cost $590 for a slug and jug, seal and all the rest of the parts. These things aren't cheap to work on.

Both of my 84's have the override and yes it can get stuck in the on position if it gets gunked up. Other than that it's like the rest with an adjustment to go up or down.
Good luck hope it's not to late.

 

[Wood Doctor]

I was thinking maybe that button was hung open if it's dumping a huge amount of oil out.

I was hoping that was the solution also. The ball on the cable attaches to a small lever that gets pulled when the button is pushed. If the ball somehow works loose or if the lever snaps, the cable attached to the ball closes up so that the manual pumper doesn't lock open in the event of failure. The manual pumper control is operating OK.

If anyone has a PDF of the 084 Owner's Manual, I'd sure like to obtain it. However, I notice that several Stihl models offer no directions to the owners for controlling bar oil flow.

 

[Wood Doctor]

An air leak will kill it. Right now all it's going to take to fix it is a set of seals...

May I ask what "seals" are you talking about? I'll get them and fix it ASAP if you can be more specific than that.

Are you talking about a new carb kit with gaskets, etc.? Usually, I only rebuild the carb when the engine won't continue to run. This one runs fine at 4500 RPM and higher, but no idle seems possible.

 

[sefh3]

May I ask what "seals" are you talking about? I'll get them and fix it ASAP if you can be more specific than that.

Are you talking about a new carb kit with gaskets, etc.? Usually, I only rebuild the carb when the engine won't continue to run. This one runs fine at 4500 RPM and higher, but no idle seems possible.

You are dealing with a very expensive saw. Parts are hard to find for these beast. Mostly only from the dealer and not many aftermarket suppliers have these parts. You need to read the link in my signature and do a vac test on the saw. You have a two crank seals. I'm betting one of them are leaking. The vac test will help you find the leak and fix the problem. Let's working on getting the saw to run right first then worry about the oiler later. Too much oil is better than not enough, in my books.

 

[smilin possum]

May I ask what "seals" are you talking about? I'll get them and fix it ASAP if you can be more specific than that.

Are you talking about a new carb kit with gaskets, etc.? Usually, I only rebuild the carb when the engine won't continue to run. This one runs fine at 4500 RPM and higher, but no idle seems possible.

No I'm talking about the crank seals. It could also bethe impulse line or anything else that lets the engine suck extra air into the case.
I tried to send you an IPL and a manual but it want let me copy the stupid thing. I can fix a saw but this puter kicks my butt.

The reason for the seal idea is that any extra air getting into the case will make it nearly impossible to adjust the carb and make any difference. Three sites to look at are the crank seals, the impulse line and sometimes a case gasket but I've found those to be rare. Do you have a way to do a vacum or pressure check on the saw. That will rule out the air leak.

If I can't get this thing to send the stuff I'll try to get LP to do it. Good luck and hollar if you have trouble.

 

[blsnelling]

It could also be a bad intake boot.

 

[Mr. Bow Saw]

I just put a oil pump in my 084. I don't have a IPL for it.
If you turn the saw upside down you will find the oil adjuster,
It will look something like this.It will not say more or less on it but
you get the idea.

 

[v8r]

yep, flip her over, the adjuster is underneath just as mr bow saw posted.

 

[2stroked2smoke]

Hey Edwin, I have new crank seals, and a new impulse hose and a new fuel line for 084 if ya need them. I also own an 084. the button for the oiler boost is not a pumper button as some of the older saws had. You just press down on it when you need extra oil, and the cable goes to the pump and changes the oil output as long as you hold the button down. If anything is keeping that cable from returning then it will be at maximum output and adjusting the screw will do nothing. I also have an original owners manual if you need to look at it. If nothing else just jump in the ranger and come on down to cambridge again and I'll help ya figure it out.

 

[Wood Doctor]

I just put a oil pump in my 084. I don't have a IPL for it.
If you turn the saw upside down you will find the oil adjuster,
It will look something like this.It will not say more or less on it but
you get the idea.

Super! That took care of the oil flow. It was adjusted wide open. I cut it in half and still have plenty of lube.

I'll have a local shop (dealer) do a vac test. They should be able to give an estimate from there. Brad's intake boot suggestion makes some sense also. I'd like to say I could fix this myself with the right parts, but without a shop manual, it's like flying IFR with twisters around. You would think with the number of these saws still in operation today that Stihl would at least offer a PDF download. Many owners just don't save their manuals or lose them. I suppose they have their reasons.

 

[mtngun]

t without a shop manual, it's like flying IFR with twisters around. You would think with the number of these saws still in operation today that Stihl would at least offer a PDF download.

PM sent to Wood Doctor.

Edit: I tried to PM Wood Doctor, but his inbox was full !

 

[Wood Doctor]

Fixed

PM sent to Wood Doctor.

Edit: I tried to PM Wood Doctor, but his inbox was full !

Fixed. Space freed up. Should be a warning somewhere, but I should check that more often. :bang:

 

[WalterWesley]

I would like a copy of the manual for the 084av please, if someone would be kind enough to send it to me

 

[Wood Doctor]

Attached is the PDF.