029 is leaking "oil"

[tstex]

Hello to All,

My 029 Farm Boss is leaking what looks like very used crankshaft motor oil.  It's coming out of the bottom of the sprocket cover area.  It looks kind of "bubbly" and almost like melted dark grease. 

Since the only oil that goes in is new/clean bar oil, what is making it so dark and contaminated, and leaking so much?  Some is also coming out of the bar nuts holes and below it too. 

Finally, not sure if it's a coil or fuel issue too, but after she has been running a bit, she'll die on or near idle and will not start up thereafter.  When she does start, she runs good.  But w the oil leaking like she is, I am not trying to extend the running time.

Is the discoloration of the oil coming out due to being heated up and burnt?  Almost looks as if I filled her w oil run for 20,000 miles, then due to a crack somewhere, it leaks that kind of oil.  I cannot see any noticeable cracks and cannot recall any recent drops.

I'm going out to ranch tomorrow, so if there's anything I need to try to troubleshoot, your help would be greatly appreciated.  I can take some pics too if it would help.

Many thanks to all,
tstex

[dougand3]

Just guessing here...maybe the inboard clutch is getting real hot and heating oil pump. Make sure brake band is not touching sprocket.
Need to narrow down exactly where oil is coming from...pull B&C and sprocket and clutch. Run saw and observe.
Carb may need tune...LA/TAS/Idle (Whatever it's called) and/or L screw.

[joe_indi]

I have seen this mostly in saws with one or more of the following:
L screw set too rich.
Leaking inlet needle
Punctured pump diaphragm
Saw dust accumulation between metering diaphragm and its cover
Worn rings and/or piston
Poor compression from piston being cracked between the rings (usually visible if the muffler is removed)
Poor/old two stroke oil
Too much two stroke oil
Slight leak between the exhaust port and the muffler.

You might ask why the oil is not visible on the flywheel side, the fan's air flow is from the starter side to the clutch side, a lot of the air is directed through the front portion of the cylinder, between the muffler and the cylinder. So any oil deposits generated for the reasons I have mentioned would be blown towards the clutch side through the gap just behind the bumper spike.

[tstex]

Thank you Doug and Joe...

I will go out in the next few days, take some pics and review your notes and see if I can get you some answers.  I do greatly appreciate your follow-up.  But, here is what I can answer now:


I have seen this mostly in saws with one or more of the following:

L screw set too rich. - has not been adjusted, even since when it was working well
Leaking inlet needle - how do you check this?
Punctured pump diaphragm - ditto ?
Saw dust accumulation between metering diaphragm and its cover - I clean out the visible accumulated oil & sawdust every 2-3 uses...also when reversing the bar
Worn rings and/or piston - will have to ck
Poor compression from piston being cracked between the rings (usually visible if the muffler is removed) - will remove muffler and look to see if piston is cracked
Poor/old two stroke oil - I have 4 chainsaws and use the same mix, gas and bar oil for all - never had a scenario where all of them exhibited the same [fuel-based] problem, so I think I can rule out this
Too much two stroke oil -ditto
Slight leak between the exhaust port and the muffler. - is there a way to ck this?

Make sure brake band is not touching sprocket - can you pls be more specific?

Thanks again

Regards, tstext

[dougand3]

Slight leak between the exhaust port and the muffler. - is there a way to ck this?

You just look with a flashlight: muffler-gasket-cylinder. That juncture may ooze unburnt black fuel, esp if running too rich. Fix by tune carb, new gasket, tight muffler bolts.

Make sure brake band is not touching sprocket - can you pls be more specific?

Metal band surrounds sprocket - it should not touch sprocket unless chain brake is engaged. If it touches during cuts, it will get real hot.

[Al_Smith]

I've seen several 029's that evidently something was wrong with the brake and it must have been partly engaged .It would crispy critter the plastic cover over the oil pump and seals .On those the oil looked about like well head crude oil .

One of those they neglected to install both the e-clip and the clutch drum bearing so the drum would run eccentric .It eventually broke one of the clutch shoes .How it ran up until  that time I'll never know as I thought it would have broken the crankshaft .

I dug through my parts and repaired it and as far as I know the thing is still running .

[tstex]

***UPDATE***

I took the muffler off, and got a view of the piston, mostly the side and the top from an angle.  I slowly pulled the starter coil to achieve a full view...I did not see anything that jumped at me as a crack.

Next, I was going to start her and then take a quick video of the leaking oil, but I could not get her to start.  Could I have re-installed the muffler incorrectly?  The bottom of the 3 long bolts slipped down some making it impossible to install the manifold gasket.  I then figured it out that it had to be pushed-up, then the gasket put on and worked backwards till it seated on the manifold.  I tried not to over torque it and didn't have a torque wrench.  I also made sure the muffler screen was properly seated before I tightened her- the first time the screen slipped down some so I had to redo it by holding it while tightening down the 3 screws.

Not sure where I go from here, but not being able to start her presents a whole new problem...I'm all ears.

Thank you, tstex

[dougand3]

Muffler installed incorrectly won't prevent starting UNLESS gasket is blocking the exhaust port or screen is clogged - blocking muffler exit.
Mufflers are pretty simple - get the bolts thru muffler holes and gasket holes.
Try a tsp of fuel mix in the spark plug hole (or carb throat and pull throttle once). Then see if it starts - may take 10+ pulls because it will be floody.

[tstex]

Thanks Doug...I'll give that a try...I'm returning tomorrow and will start from scratch again.

Will post back w results over weekend - tstex

PS - does anything I am describing entail a potential repair [parts and labor] that pretty much outweighs the fix? meaning, should I just invest in a new saw?

[dougand3]

Nothing described thus far is costly. We don't have enough data to declare it a goner.
As joe_indi states - it may be as simple as a bad muffler gasket or tuned too rich.
Could be carb trouble - flooding. A new AfterMarket carb is ~ $15.

[tstex]

***SOLUTION FOUND***

It was a bad coil...it would run for a bit, then die-out...it was overheating and cooking the oil...I was also using non-stihl bar lube that was not thick enough and it would run easier and heat/cook-up easier.  I also changed the spark plug too.

She runs fine now and can run for 4-5 min, then idles fine...I can cut her off, then she'll start right up...w a bad coil, she would not start-up again...

Thanks again for all your help guys...learned a lot on this post - tstex