Stihl 029 Super troubleshooting.........

[STIHL-KID]

I just picked up a new project (029 Super) I was able to clean it up real good and check the vitals. I checked compression.....(120psi exactly) Checked spark......(intense blue spark) I was able to add some fuel to the cylinder and get it to start and run off of what I fed it. Once the fuel is burned up, I have to spoon-feed it to start again. Basically no fuel delivery is happening. Just a little history on the saw: Bought in 2000 and stored for the last 3 years on a shelf. While stored, the fuel and bar oil tanks were empty. I'm sure a fuel tank filter and carb kit is in order. Does anyone have any other suggestions on things to check to trouble shoot no fuel delivery to cylinder? I have checked the fuel lines and impulse line, they look good and are hooked up correctly.

 

[stckciv]

Clean the carb and put in a new kit. That will fix your problem.

Gets kinda hard to cut when you have to put gas in the carb like that!

 

[SawTroll]

Do you have a dumpster close to you......

 

[drmiller100]

my dad has an 029. sometimes starts reight up, sometimes won't. when it starts, he says it runs great.

still carb kit???

 

[bigair]

120 psi is on the low side. Time for new rings. After you get it running it probably won't idle well due to the low compression.

 

[TimberPig]

Start with the carb kit and fuel filter.

The 120 psi is low, but I'd suspect the gauge as much as anything before I'd be tearing it down for a rering. If you absolutely know the gauge is correct, then it may indeed need a set of rings.

 

[STIHL-KID]

The compression was tested with a brand new (right out of the package) USA made compression tester. I conducted the test over and over and still came up with 120 psi exactly. How much psi does it take for the saw to run? What is the optimal compression level for this saw? I can hang the saw from it's starter cord, but it slowly falls after a few seconds.

 

[Lakeside53]

Do an AS search on compression testers.. It doesn't matter where your guage was made if it doesn't have a schrader valve right at the tip. The saw will have about 150 for most of its life. Up to 160 new'ish, maybe 140 after a 1000+ hours, unless abused


Most common cause of your problem on the 029 is a bad fuel line. Seal problems are rare. At 120, if it is correct, it will barely start, and run bad anyhow. "just rings" - at 120 it's more likely you have a scored piston/cylinder than just rings (but it is possible). Pull the muffler and check it out.

Carb kit? Why not.. for $5, it's worth it. Make sure you inlet screen is clear.

 

[STIHL-KID]

Thanks for the reply Lakeside! Yeah, when I got the saw a few days........first thing I did was pull the muffler and look at the piston. Everything looks clean, no scratches or discoloration. I included a pic so that thread viewers may chime in on what they see. How much are new piston rings? Thanks

 

[mountainlake]

Do you have the throttle clamped wide open when doing the comp test? If not you'll get a low reading. Steve

 

[Scooterbum]

Way to go

Do you have a dumpster close to you......

Nice contribution from an assumed intelligent source......
Just what the guy wanted to hear when he's just looking for help....

 

[mountainlake]

Scooter You should'nt be so hard on Mr. Troll. We all know the ony good saws out there are a Jonny 621, Husky353g, StihlMS361, and a Husky372. Steve

 

[stihl025]

Do you have the throttle clamped wide open when doing the comp test? If not you'll get a low reading. Steve

Stihl Kid,

Don't let this reply get lost amongst the SawTroll beating. I am interested in your findings. We could be giving you bad advise possibly from an incorrect compression test.

 

[TimberPig]

The compression was tested with a brand new (right out of the package) USA made compression tester. I conducted the test over and over and still came up with 120 psi exactly. How much psi does it take for the saw to run? What is the optimal compression level for this saw? I can hang the saw from it's starter cord, but it slowly falls after a few seconds.

Until you've tried it on something other than just this saw, and preferably against a known good gauge, I'd be suspect of the compression test reading. Just because a gauge is new and made in the USA, doesn't mean it is accurate. Many engines get rebuilt because the gauge was faulty, and the person failed to suspect the reading from their gauge before they tore the engine down.

 

[STIHL-KID]

Not sure if this matters...... but when I checked the compression, I had the saw fully choked. Does throttle position have a big part in what compression reading you'll get? I'm trying my best to stay on the same page as everyone else on this thread. Honestly, the piston looks great and so do the cylinder walls.

As for Sawtroll.........:notrolls2: someone has to throw in a wise-crack comment to add comedy to a technical thread, right?

 

[Lakeside53]

I find it makes little difference - maybe a pull extra, maybe. But you have the saw and the tester so just try it..

Saw-troll was just having his fun... he just didn't noitice he was a stranger to the audience.

BTW, yesterday I had an 029 doing extactly what yours is doing. It seemed like an air leak but it was actually a carb meeting diaphragm that was so stiff (like drum skin) that it was unable to flex in response to the engine needs. Started on choke after way too many pulls, ran for a few seconds, then died... It has been "stored" for about 5 years.

 

[mountainlake]

Yes you have to have the choke and throttle wide so it can get air into the cylinder. Steve

 

[Lakeside53]

The air get in, if not it would never start! In any case, the muffler is wide open and a great source of "air".

 

[mountainlake]

Air is coming out of the muffler and in the carb, if it can't get in it won't fill the combustion chamber full = less compression.. Steve

 

[charlesfarm]

Actually, it doesn't matter if you have the throttle open or not, the cylinder will get the air it needs from the exhaust port. In a two cycle engine, the piston exposes the open exhaust port every time it passes downward beyond the port -- the pressure will equalize in the cylinder with the pressure outside the engine.

120 pounds is plenty of compression to get that saw to run.

You have one of three things going on:
1. pinched or cracked fuel line
2. clogged fuel filter
3. carburetor needs rebuilt

If you rebuild the carburetor, be sure the metering lever is properly set. Walbro makes a gauge for checking the lever height -- it is absolutely essential to get the height correct for it to work properly. Also, only use a spray type carburetor cleaner, the old-fashioned dip style will destroy these little two cycle carbs (That lesson cost me $60 when I destroyed the check valve in a customer's carb and had to buy a new one.)

Hope this helps!

God bless,
Chris Charles