Stihl 031 pulsing

[Isidro]

Some advise, please,
I am out of ideas. My saw will start but I cannot get it to idle right. I have pressure test the body core, no leaks. I did not replace any oil seals. I exchange the existing carb with a good and working carburetors, problem still persists. I have pressure tested to tank and fuel line and replaced the impulse line and inspected the manifold rubber that makes the connection to the cylinder and carb. I even replaced the clutch. I took out the points and capacitor and installed an electronic chip, I have great spark. I can turn down the idle and readjust the carb low speed screw but the pulsing continues or I get things turned down too much and the saw dyes. The saw starts right up but is really not working correctly. The saw runs long enough to get hot. My skill level has been exceeded and do not know what to try next. It could be I should start from the beginning and retest everything again. My goal is to not drive the saw down to my Stihl shop and drop it off. Any thoughts or recommendation would be greatly appreciated.

Thank you, Tony

 

[Snowchaser]

If you put an electronic chip in an 031, you have you take off the flywheel, remove the flywheel key and advance the timing. If I remember correctly, it is about 3/4” clockwise on the outside edge of the flywheel. Otherwise the timing is so far off, that the muffler will turn red hot, and will run like crap

 

[Isidro]

Thank you for getting back to me. My saw, when running, runs very hot. Not hot enough to turn the muffler red but hot because the saw does not run long enough. Clearly there is a lot of heat coming off the saw. Right now I think your advice is "spot on"

As I conceded my skills are limited. I have never advance the time on a chainsaw. I do get the part about turning the flywheel about 3/4" clockwise but I am not sure how to do that. First, what I am thinking is I need to remove the set key and fill the left side of the key down so when I put the flywheel back on it can be positioned 3/4" to the right, that is clockwise. Without a timing wheel, which I do not have, I could mark a flywheel fin and the saw body and the get the flywheel to move around 3/4" by filing down the set key. Maybe it will take a couple of times to get it right. Just don't over file it.

Do I have the process right? Is that the way to do it?

 

[Old2stroke]

Some advise, please,
I am out of ideas. My saw will start but I cannot get it to idle right. I have pressure test the body core, no leaks. I did not replace any oil seals. I exchange the existing carb with a good and working carburetors, problem still persists. I have pressure tested to tank and fuel line and replaced the impulse line and inspected the manifold rubber that makes the connection to the cylinder and carb. I even replaced the clutch. I took out the points and capacitor and installed an electronic chip, I have great spark. I can turn down the idle and readjust the carb low speed screw but the pulsing continues or I get things turned down too much and the saw dyes. The saw starts right up but is really not working correctly. The saw runs long enough to get hot. My skill level has been exceeded and do not know what to try next. It could be I should start from the beginning and retest everything again. My goal is to not drive the saw down to my Stihl shop and drop it off. Any thoughts or recommendation would be greatly appreciated.

Thank you, Tony

Can you be more specific about what "pulsing" means? Is it just an unstable idle speed that hunts up and down or something else?

 

[HarleyT]

It depends on which "chip" you put in.

 

[Isidro]

Can you be more specific about what "pulsing" means? Is it just an unstable idle speed that hunts up and down or something else?

Thanks for getting back to me. When the saw first starts up it runs fast so I turn down the idle, slowly. The saw slows for a while then speeds after I rev the engine so I fiddle with the idle and sometime rev the engine to keep it running. The engine never stabilizes - speeds up and then down or stops. I do make small adjustments on the low speed carb screw but that does not solve the problem. The saw does run very hot for the short amount of time it is actually running which is 2 to 5 minutes at one time. The saw is responsive to the throttle.

Again, thank you, Tony

 

[Isidro]

It depends on which "chip" you put in.

I installed the Nova chip.

Thank you for getting back to me, Tony

 

[SweetMK]

I used to tinker with Kohler engine powered garden tractors,
on them, you could get overheating, and red glowing muffler condition when the ignition condenser (another name for capacitor) went bad.
The engine ran "sort of " normal,, with the bad condenser.

So, is there an obvious capacitor in the ignition system somewhere?? If it is defective, that would also change the timing.

 

[Isidro]

I used to tinker with Kohler engine powered garden tractors,
on them, you could get overheating, and red glowing muffler condition when the ignition condenser (another name for capacitor) went bad.
The engine ran "sort of " normal,, with the bad condenser.

So, is there an obvious capacitor in the ignition system somewhere?? If it is defective, that would also change the timing.

I removed the capacitor and points, and installed a chip. I am struggling as to how to change the timing, never done that before.

Thank you for getting back to me,
Tony

 

[Snowchaser]

you dont need a timing wheel, like you said, just mark the case and flywheel, then remove the flywheel. Remove the key as there isn’t enough to file down. Its a taper shaft and i have never had one slip. I have done 2 now and i used green loctite on the shaft for extra insurance. It is for bearing journals and such. Rotate the flywheel clockwise 3/4” and bolt back down. Test it out before putting loctite on. It just makes it easier to adjust it if needed. The flywheel magnets on the points version aren’t in the same place as the electronic version i think. My 032 was a direct removal of points and install of chip without messing with the flywheel. Both my 031’s have been running great for 3-5 or so years now. Not that there aren’t carb issues going on as well, but changing timing with a chip on those is a given. I also have an electronic 031 that was my standard for performance. The chip conversion ones ran the exact same cut times as the electronic.

 

[Snowchaser]

I started with nova chips and had a few bad ones so i switched to the johndeere/kawasaki one #m70114.

 

[Isidro]

you dont need a timing wheel, like you said, just mark the case and flywheel, then remove the flywheel. Remove the key as there isn’t enough to file down. Its a taper shaft and i have never had one slip. I have done 2 now and i used green loctite on the shaft for extra insurance. It is for bearing journals and such. Rotate the flywheel clockwise 3/4” and bolt back down. Test it out before putting loctite on. It just makes it easier to adjust it if needed. The flywheel magnets on the points version aren’t in the same place as the electronic version i think. My 032 was a direct removal of points and install of chip without messing with the flywheel. Both my 031’s have been running great for 3-5 or so years now. Not that there aren’t carb issues going on as well, but changing timing with a chip on those is a given. I also have an electronic 031 that was my standard for performance. The chip conversion ones ran the exact same cut times as the electronic.

Great, I am confident as to my path forward. I will get to it today. One more question - should I change my existing flywheel and replace it with an electronic flywheel? I do have one in my spare parts bin? Would that make a difference and not require a timing change?

 

[Isidro]

Great, I am confident as to my path forward. I will get to it today. One more question - should I change my existing flywheel and replace it with an electronic flywheel? I do have one in my spare parts bin? Would that make a difference and not require a timing change?

the new flywheel part number is: 1113 400 1201

As always, thank you, Tony

 

[Snowchaser]

Its possible. I don’t think i tried that at the time. Would make sense to me. Definitely worth trying.

 

[Isidro]

Thanks, I will wait on the other flywheel. I file the key so it moves the flywheel just short of 3/4" I will put everything back together and run the saw. If it still need some adjustment I will have just a little more file to do. I think, better short than long at this point.

 

[HarleyT]

Here is the chip that fits on the 031. No need to pull the flywheel, advance the timing, etc.
Also all of the other models it works/comes on.

 

[HarleyT]

The Oregon/Kawasaki chip works on the 032 and the Echo 500vl, and many others.

 

[Isidro]

Here is the chip that fits on the 031. No need to pull the flywheel, advance the timing, etc.
Also all of the other models it works/comes on.

View attachment 968757

Here is the chip that fits on the 031. No need to pull the flywheel, advance the timing, etc.
Also all of the other models it works/comes on.

View attachment 968757

Do you think the Nova chip will work on a 031? I do have a Kawaski I could use. The Kawaski is a single prong unit for the hot lead. And you ground the unit and kill switch to the body. I think that is correct?

 

[Isidro]

Thanks, I will wait on the other flywheel. I file the key so it moves the flywheel just short of 3/4" I will put everything back together and run the saw. If it still need some adjustment I will have just a little more file to do. I think, better short than long at this point.

I got it all back to gather. The saw is running better but not great. I ran it much longer, boy did it get HOT. It's cooling now. I am thinking I should advance it more? What do you think?

If I am still struggling I might change the chip to a Kawaski chip and go with the electronic flywheel. Any thoughts on that approach? If you recommend going with this approach I do have another key that I can use to go back to the original timing.

Don't give up on me, I very much appreciate all your help, Tony

 

[Isidro]

Do you think the Nova chip will work on a 031? I do have a Kawaski I could use. The Kawaski is a single prong unit for the hot lead. And you ground the unit and kill switch to the body. I think that is correct?

Great attachment, can you attached the site so when I open it I can read more about chips, timing, and flywheels. I assume the site you got the table from has that kind of information, sure hope so.

Again, thank you, Tony