My Stihl 029 problem

Weekend_Sawyer · October 07, 2003, 09:00:43 AM

I have an 029 farm boss with 20" bar. I bought it new 3 years ago and have used it quite a bit. It has developed a problem. When it gets warm it will stall out. It cuts very good when it is into a log but when limbing or after a cut it will stall out when you pull the trigger.
I have changed the air filter twice it seemed to help for a little while. Installed new spark plug, put in new gas line filter and adjusted the high and low mix screws. I took it back to the shop where I bought it and they just called and said there is no problem.

Any Ideas?

If I cannot repair the problem I am going for a new saw. Any suggestions on a better medium sized (20") Stihl?

WS

Kevin · October 07, 2003, 10:14:33 AM

What test did they perform on it?
Is the plug wet or dry when it stalls out?

Jim_Wahl · October 07, 2003, 01:19:32 PM

Be sure to check and see if the spark arrestor is plugged up.

Weekend_Sawyer · October 07, 2003, 01:20:09 PM

Kevin,
I am going to pick it up tonight, I'll run it and check the plug when it dies and post later tonight.

Jim, I'll check that too.

Minnesota_boy · October 07, 2003, 05:14:02 PM

If this isn't an ignition problem, remove the carburetor and remove the cover on the pump side, the side that has a more convoluted appearance. Look for a pasageway that is about 3/8 inch diameter. This pasageway has a fine mesh screen in it to collect any crud that made it through the filter before it clogs some smaller pasageways beyond. Look for a collection of small fibers plugging this screen. If it gets bad enough, the saw will stall out in the cut as it can't get fuel fast enough. I use the point of my pocket knife to scrape the crud off the screen and I'm back in business.

Weekend_Sawyer · October 07, 2003, 06:25:10 PM

ok, I was running it some tonight and here are some more simptoms. After warming up it will run wide open fine, cut a log fine, but if alowed to idle for about 10 seconds it stalls, as it stalls sometimes you can pull the triger and bring it back and other times it stalls out. When limbing after a cut when you go to pull the trigger for the next cut it sometimes stalls out.

It's a fairly new plug. I pulled it after it stalled and it was dry, and the anode was light on one side and dark on the other. Gap was 20 and I enlarged it to 25 and it seemed to run better but I ran out of light and did not get a good test in.

This is a strange one.

Kevin · October 07, 2003, 07:22:05 PM

I'm guessing here but with a saw that new the seals or gaskets shouldn't be leaking but you never know without pressure testing.
Things to check for would be tank vent,restricted fuel line or dirty filter, proper jet settings, maybe loose body screws on the carb.
Do you store fuel in the saw for long periods?

Minnesota_boy · October 07, 2003, 07:22:20 PM

Hmmm.... It still sounds like carburetor, but now it sounds more like a leaky float valve. Take the carburetor off the saw and remove the plate over the float diaphram. Remove the diaphram, being sure to unhook the pin from the valve arm. Carefully remove the screw holding the valve arm and watch where the spring flies off to. (it's better to hold the spring with your finger, but I rarely remember to do that) Remove the valve needle and wipe the tip with a soft cloth, making sure you leave no lint on the tip. Put it back together and put the carb back on the saw. Try running it. Report back here.

Kevin · October 07, 2003, 07:32:43 PM

Your plug should be .020".

ladylake · October 08, 2003, 03:22:41 AM

Sounds more like a dirty carb. When you have it out clean all the passages. Take both high and low needles out and blow air through the holes. If it was flooding due to a leaky needle it would be smoking a lot when you opened up the throttle. Steve

Weekend_Sawyer · October 08, 2003, 11:10:42 AM

I'm thinking carb also. This chainsaw gets used quite a bit so fuel should not be a problem. I don't store fuel long either, just dump it in the truck and mix up some fresh stuff.

I am going to try one new spark plug, caus it is easy, then pull the carb. can you walk me through re adjusting it after i get it back in?

Should I pick up new gaskets before I get started?

Thanks
Jon

Kevin · October 08, 2003, 02:25:11 PM

Jon ;
Try cleaning the carb on the saw first.
If that doesn't work carb rebuild kits are relatively inexpensive.
We can get you readjusted but you should get someone to do the final test with a tach if you don't have one.

Weekend_Sawyer · October 09, 2003, 11:17:04 AM

Well, suffered a slight setback last night.

I pulled the carb and took the bottom off and there was some crud in there, not much but mabe enough. I put the air sprayer on the compressor, (Let me interject here that I almost always remember to drop the regulator down to 40 psi while doing small work... almost always) and promptly blew the carb bottom, gasket and diaphram across the barn at 120 psi. I did find the bottom but gasket and diaphram are nowhere to be found.

I went out at lunch and ordered a rebuild kit from my local supplyer. They had a good laugh at my misfortune. One old guy in the back said "Yup, that'l happen".

Kevin, tell me more about the tach, is it specific to Stihl or would an automotive one work, and how would you connect it?

Kevin · October 09, 2003, 11:28:15 AM

I have the A model and it works well on all my saws...

http://www.madsens1.com/tach.htm

Weekend_Sawyer · October 09, 2003, 02:05:26 PM

I'm heading down to Colonial Beach VA to do a decking job this weekend. I'll get back to you all on monday with the continuing saga of how not to fix an 029

I did just order the B model Tach ;D

SasquatchMan · October 10, 2003, 06:48:17 PM

WS I assume you'll get your 290 running again, but if not, and you want a "better" Stihl, then you need to get into the "even numbered" saws... the 340 would be the "pro" equivalent of the 290, and the 360 is bigger than that... The 310 and 390 are just big-bore versions of the 290, and quality in this series of saws is not the same as the pro saws. The 290 is decent, (it better be, I just bought one), but it's not of the same ilk as the pro saws.

Weekend_Sawyer · October 13, 2003, 05:32:13 PM

Yeeee Haaaa, were back in action.

I picked up the rebuilder kit and installed it this evening. Was able to cut about 1/4 cord with no problems. 8) 8) 8)

Found:
Fine grit in the bottom of the carb.
Original needle valve had a rubber? tip which was dirty and indented. New one is all metal.
Diaphram had grit on top of it.

I should be receiving my tach any day now. Then I want to dial it in.

Thanks for all the help guys.

WS

Gus · October 13, 2003, 09:43:14 PM

WS,
I love it when things come together. Wonderful!!! 8)

jokers · October 14, 2003, 03:08:15 AM

Hi Weekend Sawyer

I hope that you flushed your fuel tank and checked the filter and pick up hose in the tank if you found grit in your carb. I`d flush my gas cans also because something is amiss, first by introducing the grit to your fuel tank and second by the fact that it made it to your carb. How much do you suppose made it to the wear surfaces of your piston/cylinder and rings?

Russ

Weekend_Sawyer · October 14, 2003, 11:17:57 AM

Hi Russ,

Good advce. When I started having this problem I did change the tank filter and flushed it. I also changed out the air filter and put in a new plug.

When the gas gets a little old I put it in my truck, as suggested by someone here, truck does not mind at all!

WS

Weekend_Sawyer · October 17, 2003, 12:47:39 PM

Heay Kevin,
My digital tach just came in. can you give me the RPM ranges and your procedure for dialing in the carb on this 029? It runs pretty good now, plug is a little dark so it is close.

Thanks
WS

Kevin · October 17, 2003, 02:50:37 PM

Your manual should have the rpm.
Try this link for starters ...
http://www.madsens1.com/sawtune.htm

Kevin · October 17, 2003, 03:32:42 PM

Be sure the air filter is clean.
The no load speed for that saw should be NO MORE than 13,000rpm.
The idle speed for my 62cc Husqvarna is 2500rpm just to give you an idea.

SasquatchMan · October 17, 2003, 08:25:41 PM

While yer at it with the tach, Stihl says the oil output should be between 6 and 15 ml per minute at 10000 rpm, depending on where you've set the flow rate.

Weekend_Sawyer · October 17, 2011, 01:45:14 PM

Wow, so many years ago and I never fixed this saw. I wound up buying a nice 044 from a FF member and shelved the 029.

Well I figured it was time to give it another try. I always liked that saw.

I took the housing, handlebar and brake off and am going to replace the gasline and impulse lines even tho they don't look bad. If still bad then I'll rebuild or replace the carb which I had rebuilt before.

I did a compression check and it has 130psi. piston and cylinder look smooth

Anything else you guys can think of?

Jon

joe_indi · October 17, 2011, 02:43:21 PM

(Golly! Is this really an eight year old thread?)

Quote from: Weekend_Sawyer on October 07, 2003, 06:25:10 PM
........I pulled it after it stalled and it was dry, and the anode was light on one side and dark on the other

This is a sure indication that though the carb is set rich, the saw is gradually being starved of fuel.
Some possibilities come to mind.
* A blocked air vent in the fuel tank.The 029 has the tube and screw vent if I am not mistaken. Just a bit of sawdust intrusion into the tube would clog the vent.To check if this is the cause, when the saw reaches the stalling stage open the fuel cap and close it.This will equalize the pressure in the tank.The saw will then run normally for some time.
* A partially clogged impulse hose.This would weaken the impulses to activate the pump diaphragm fully.The result would be that under load the fuel supply will not be able to catch up with the demand.
Its possible to pull out the impulse hose and check for partial blockage by blowing through it.If there is any resistance, clean the hose out or replace it.
* A sticky jet valve. This causes air to leak into the metering chamber so that the fuel level in the chamber drops till the engine stalls. Try replacing the jet valve.
* I had a 029 come to me with a similar stalling problem and this is what I found before I lost my wits.
The saw did have air compensator.But the bit of the air filter that seats into the air compensator was sealed, probably for a carb without the air compensator.This sealed end seats so well into the rubber boot of the air compensator that it forms an airtight seal.This in turn prevents the metering diaphragm from moving downwards to activate the metering lever.This results in the saw becoming leaner and leaner till it dies from fuel starvation.
Try running the saw without the air filter.If it runs better check out the air filter.
Just punching a couple of pin holes in that sealed bit of that filter solved the problem for me.

If any of the above work for you after these eight years, I will be really happy.
Good Luck.

Joe

Weekend_Sawyer · October 17, 2011, 08:43:53 PM

8) 8) It's runnin!! 8) 8)

I replaced the impulse and fuel lines and got it runnin but same ol problem, didn't want to idle and when you pulled the trigger it would sound like it was runnin out of gas. I also noticed that when I ran it without the air cleaner it would blow gassy fog out of the carb when it was bogging down.

I rebuilt the carb and the needle valve had green sticky stuff on it. Mabe from sittin for so long? I don't know if it was replacing the diaphram or the needle valve but it's runnin pretty good. I was cutting with it tonight.

BTW I found the tach I bought to set this one up so after I get a replacement battery I'll set the high idle.

Thanks for all your help.
Jon

joe_indi · October 18, 2011, 01:30:32 AM

Quote from: Weekend_Sawyer on October 17, 2011, 08:43:53 PM

8) 8) It's runnin!! 8) 8)

I replaced the impulse and fuel lines and got it runnin but same ol problem, didn't want to idle and when you pulled the trigger it would sound like it was runnin out of gas. I also noticed that when I ran it without the air cleaner it would blow gassy fog out of the carb when it was bogging down.

Blowing gassy fog eh?
The flywheel key is broken and the ignition timing is off.
Please check this out and confirm.

Joe