Well........Scratch My Head On How This Saw Ran!!!

I just got done doing some saw maintainance for a friend. His Stihl 036 just wouldn't run. I checked the spark and that was good so I turned my attention to the carb. I took it apart and found some dirt. I figured this was the problem......boy was I wrong. As I was looking at the saw I noticed that one one the cylinder bolts was backed out, turns out that one was backed out about 5 turns, two were just loose and one was completely out. I tightened everything back up and the saw runs real good. Has anyone ever heard of this happening?


The next saw was just a muffler mod. The saw is a Stihl 029 Super. Here again it is amazing that this saw ever ran. In the pic below you will see 2 small elongated holes, that is what it ran out of. Of course this saw had the typical baffle with the swiss cheese hole effect. This muffler was real nice to mod. The part that I cut out is actually a recess, as if they put it there for those of us who are power hungry. I cut this little square recess out and the muffler is open straight into the exhaust port.


In the picture you will notice a piece of metal running across the cylinder side of the muffler. This is just a scrap piece from the muffler that the muffler was sitting on for the picture.

The front deflector I just cut to match the opening.

The finished muffler on the saw. This saw really woke up just in throttle response alone!

Man Rich! Does that muffler manage to maintain any backpressure at all? (Ya know that a little BP is a good thing?)

Originally posted by Stumper
Man Rich! Does that muffler manage to maintain any backpressure at all? (Ya know that a little BP is a good thing?)

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It should be OK. I ran a port that big on one of my 36cc Shindaiwas and it runs real good!!!

036 Screws

Kind of surprised you had loose screws on that saw, but it's not impossible. All the screws on that saw are self-locking Torx so they should not be backing out. Hopefully it didn't hurt the piston any. How long did he run the saw that way?

My 028 had a scored piston, so I started to take it apart to find the cause. Found all the base screws were finger tight. Compression was still pretty good.

Had an 045 whose screws got so loose (one or two fell out), the jug started banging around and the saw just quit. Nothing was hurt. Took the saw partially apart, cleaned the screws and carefully reassembled. Still running fine.

Chris B.

I have hade some Huskeys (44,444,371,240,340 if i remember correct) With lose cylinderbolts.

Re: 036 Screws

Originally posted by cbfarmall
Kind of surprised you had loose screws on that saw, but it's not impossible. All the screws on that saw are self-locking Torx so they should not be backing out. Hopefully it didn't hurt the piston any. How long did he run the saw that way?

Chris B.

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I really don't think he ran it that long, only because the saw was sucking so much air that it wouldn't run.

RAHTREELIMBS about 10 years ago i bought 2 used 084s i gave 500 bucks for the pair of them one ran the other didn't Turns out the that didn't run 3 of the 4 cly. base screws were compleatly loose and one stayed tight breaking off the whole conner of the jug - 250 bucks latter & a new jug & piston it's a good saw now Also i rember working on a 084 for a local tree service it was making a wierd whisteling sound when u tried starting it - it had loose cyl base screwes aswell

Sounded like a <a href="http://www.arboristsite.com/showthread.php?threadid=8574&highlight=loose+bolt" target="_blank">bell-ringer</a>

I had a newer 046 bust 2 bolt heads off and one fell out and one was just loose.

no idea why.

Muffler Screen

Rich , do you know what the open area of the screen is that you used ?

Re: Muffler Screen

Originally posted by scottr
Rich , do you know what the open area of the screen is that you used ?

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From just an eyeball look it was roughly the muffler port was the size of the exhaust port. As far as inches go, I am not sure.

Screen

Rich , the open area of the screen is probably somewhere between 51% and 72% depending on wire size and hole size .

Re: Screen

Originally posted by scottr
Rich , the open area of the screen is probably somewhere between 51% and 72% depending on wire size and hole size .

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If it makes things easier, I used the stock screen.

029

Nicejob as usual.

Now, just a caution.
The 029 carburetor is a semi-fixed jet design. Make sure you have extra fuel out of the cut on this one. It does not like lean, no way, no how. The carb may also fool you, it can be finickey to adjust outside normal parameters.

I have a modded muffler kicking around here for an 029, wth Chris's help, of course.

Just don't want you to get bit by unknowns.