stihl 031 chugs - doesn't start

[xrbbaker]

I posted this last night but it disappeared...

My dad bought the saw new, handed down to my older brother, handed down to me. I've had it for about 7 years and it always started. Lately, not so much. chug, chug, chug-chug-chug, stop. It just won't keep going. Tried starter fluid. Nope. Replaced spark plug (but didn't gap it, what should it be?) same result. Dumped gas and got the Stihl pre-mixed gas. Same result. Got carb kit and cleaned it all up and put in new gaskets, etc., same result. I then reset the idle screws and pulled. Thought it might have chugged a bit better. Pulled again and the rope broke!

1) My older brother says don't try to replace the rope. The spring will pop out and is almost impossible to put back in. I just saw a you tube demo on replacing a string for a Stihl concrete saw and that didn't look too bad. Is this doable reasonably easy like I think or should I take to repair?

2) With my graphic description of the chug no start problem, any suggestion what to try next? I'm not much of an engine guy but willing to try.

Thanks!!

 

[lone wolf]

I posted this last night but it disappeared...

My dad bought the saw new, handed down to my older brother, handed down to me. I've had it for about 7 years and it always started. Lately, not so much. chug, chug, chug-chug-chug, stop. It just won't keep going. Tried starter fluid. Nope. Replaced spark plug (but didn't gap it, what should it be?) same result. Dumped gas and got the Stihl pre-mixed gas. Same result. Got carb kit and cleaned it all up and put in new gaskets, etc., same result. I then reset the idle screws and pulled. Thought it might have chugged a bit better. Pulled again and the rope broke!

1) My older brother says don't try to replace the rope. The spring will pop out and is almost impossible to put back in. I just saw a you tube demo on replacing a string for a Stihl concrete saw and that didn't look too bad. Is this doable reasonably easy like I think or should I take to repair?

2) With my graphic description of the chug no start problem, any suggestion what to try next? I'm not much of an engine guy but willing to try.

Thanks!!

Lots of things it can be start with a compression test post the numbers ,next thing is it getting enough fuel ,then is the spark strong?

 

[Ironhand]

Have you changed the fuel/filter and impulse lines? Does it have a points or electronic ignition?

 

[xrbbaker]

I don't know what a compression test is and I'm sure I wouldn't have the tools for it. I did get it started a few days ago just one time (using starter fluid) and once it got going it ran absolutely fine. Then couldn't start it again.

Regarding points or electronic ignition - I don't know. As I said I'm not much on engines. What do I look for to tell?

Thanks for the guidance.

 

[Ironhand]

I don't know what a compression test is and I'm sure I wouldn't have the tools for it. I did get it started a few days ago just one time (using starter fluid) and once it got going it ran absolutely fine. Then couldn't start it again.

Regarding points or electronic ignition - I don't know. As I said I'm not much on engines. What do I look for to tell?

Thanks for the guidance.

As far as I know, the newer models like mine with electronic iggys will say "electronic" on the model ID plate on the top of the saw. Otherwise (unless someone did a conversion some time in the past), it has points.

Before you dig into any of that though, I would change the outer fuel and impulse lines with 1/8" Tygon tubing. The outer supply line from the tank to the carb is easy to get at, and with the carb and airbox removed, the impulse line can be changed.

 

[xrbbaker]

Hey now! That sounds like something I can do. This saw is about 35 years old so I would guess then that it has points. I'll replace the tubing and see how that goes. It does feel to me like it isn't getting fuel, which is why I rebuilt the carb. That was kind of fun btw.

thx

 

[Fifelaker]

Do not use starting fluid use a little mix instead. Starting fluid is bad JUJU on 2 strokes.

 

[xrbbaker]

Oops. Might I have screwed something up w the starter fluid?

 

[russhd1997]

When you had the carb off did you look at the piston and cylinder? Was there any scoring? It is better to remove the muffler and look at the piston and cylinder from that side as that is where it will melt first if the saw is run too lean. If there is a lot of scoring that could be the cause of the no start problem. If everything looks good then look into spark and fuel system problems. Also check the spark arrestor screen if it has one. If that is clogged it could be the problem as well.

 

[xrbbaker]

Brother Russ! Welcome and thanks for the help. Here are some new developments.

I grabbed some nylon string and replaced the pull cord. That was pleasantly easy. I also pulled out the little filter from the fuel tank and cleaned it - although it was already pristine. Then back to pulling. Exact same behavior as before. If there is a pattern it is this. Pull a few times w throttle locked on and choke on, chug. No chug-chug-chug-chug, stop. After that turn choke off and pull. Chug-chug-chug-chug-chugchug-chug-chug-chug, stop. Repeat. If while it is doing its chug-chug-chug I press the throttle lever it stops immediately. Could it be getting too much gas? It was dripping fuel. Is that normal from the multiple pull attempts and maybe flooded or symptomatic of something?

Questions:

1) When I rebuilt the carb and was putting back onto the saw I noticed that there is a black seal on the engine that the carburetor snugs up against. It looks pretty beat up. What is that? I looked but I didn't have anything like that in my carb kit.

2) What is a spark arrester screen and where do I find it?


Thanks.

 

[russhd1997]

Brother Russ! Welcome and thanks for the help. Here are some new developments.

I grabbed some nylon string and replaced the pull cord. That was pleasantly easy. I also pulled out the little filter from the fuel tank and cleaned it - although it was already pristine. Then back to pulling. Exact same behavior as before. If there is a pattern it is this. Pull a few times w throttle locked on and choke on, chug. No chug-chug-chug-chug, stop. After that turn choke off and pull. Chug-chug-chug-chug-chugchug-chug-chug-chug, stop. Repeat. If while it is doing its chug-chug-chug I press the throttle lever it stops immediately. Could it be getting too much gas? It was dripping fuel. Is that normal from the multiple pull attempts and maybe flooded or symptomatic of something?

Questions:

1) When I rebuilt the carb and was putting back onto the saw I noticed that there is a black seal on the engine that the carburetor snugs up against. It looks pretty beat up. What is that? I looked but I didn't have anything like that in my carb kit.

2) What is a spark arrester screen and where do I find it?


Thanks.

The black seal is the intake boot. It is important that it isn't cracked and is securely mounted on the flange on the cylinder and the flange on the air box.

The spark arrestor is a small piece of screen in the outlet of the muffler. If it plugged up the saw cant breathe and won't run.

If it is dripping gas it is flooded. It will need to be dried out before it will run. Empty the fuel tank, remove the spark plug, tip the saw upside down and pull the cord until no more fuel mix comes out. Let the saw sit this way overnight then put the plug back in and see if it will start.

 

[xrbbaker]

Hmm. Intake boot. I'll see if my local stihl dealer has one. I'm settling in for the night. I'll try the drain the gas trick tomorrow. thx!

 

[Cody@SPE]

Its your points. People bring these saws in all the time. After 30 plus years of use, the points get out of adjustment. Set the points and your good to go!

 

[50blues]

Its your points. People bring these saws in all the time. After 30 plus years of use, the points get out of adjustment. Set the points and your good to go!

Mine did the same thing. Check your points. A weak spark will cause this. Do a search for points on 031 or 032 you will find a lot of info.

 

[Sagetown]

A saw that old , I would replace all the fuel lines. They tend to get brittle and suck air. The intake boot may also be faulty by now too. If it don't start by then, as previously stated, replace the points. And!, above all, Keep us posted!

 

[xrbbaker]

throw in the towel

Ok guys - I cleaned and rebuilt the carb, replaced the pull rope, cleaned the tank filter, new spark plug, new gas - same chug chug. I took it to the local Stihl dealer to order new fuel lines. I ended up talking to the chainsaw fix-it guy and he said they never rebuild the carbs now. They just throw them away and install new ones. I was about to order a new one when I asked about the intake boot. I thought I'd order that as well. He said that isn't a simple gasket that to replace it I would have to crack the engine in half. that is beyond my ability and certainly my time. At that point I dropped it off for them to give me an estimate on what they think it would take to fix. I love the old saw but if they want to charge me more than $200 I think I will pass and just put that money toward a new one. After 37 years and 2 generations of use I'd say the Baker family has gotten their money's worth. Even if I do get a new one I think I'd keep the old one around. I really got a kick out of rebuilding the carb and I'd love to play around with it more - I simply don't have the time right now and I have a tree that has to be cut up and removed or the Mrs. is going to kill me!

 

[MechanicMatt]

Even after you buy a new saw don't get rid of your dads saw. Did you try cleaning the points before giving it to the dealer? What did the spark look like? BLUE or white? Its a null point now I guess they have it not you. Good Luck man and don't get rid of it, set it aside for awhile and then go back and you'll fix it.

 

[RAMROD48]

Ok guys - I cleaned and rebuilt the carb, replaced the pull rope, cleaned the tank filter, new spark plug, new gas - same chug chug. I took it to the local Stihl dealer to order new fuel lines. I ended up talking to the chainsaw fix-it guy and he said they never rebuild the carbs now. They just throw them away and install new ones. I was about to order a new one when I asked about the intake boot. I thought I'd order that as well. He said that isn't a simple gasket that to replace it I would have to crack the engine in half. that is beyond my ability and certainly my time. At that point I dropped it off for them to give me an estimate on what they think it would take to fix. I love the old saw but if they want to charge me more than $200 I think I will pass and just put that money toward a new one. After 37 years and 2 generations of use I'd say the Baker family has gotten their money's worth. Even if I do get a new one I think I'd keep the old one around. I really got a kick out of rebuilding the carb and I'd love to play around with it more - I simply don't have the time right now and I have a tree that has to be cut up and removed or the Mrs. is going to kill me!

Well he dont know his arse from a whole in the ground...YOU DO NOT HAVE to split the engine in half to replace the manifold boot...Go get your saw and take it to someone who knows what they are doing....

 

[Cody@SPE]

Split the case to put a intake boot on? Sounds to me like this soo called "chainsaw guy" needs to hop in his Prius and leave. Those saws were the easiest Stihl saws ever made to change the intake boot on!

 

[Rookie1]

Ill say condenser. Guessing its a points model. Too late for me to look up threads. Do a search for 031 ignition or 031 condenser or 031 spark. You should find plenty of advise.Somewhere just yesterday I posted on an 032 thread that had a similar problem. Funny how things come in waves.
Read this http://www.arboristsite.com/chainsaw/187115.htm