Chainsaw Question

[thewoodlands]

I have a 310 Stihl I like using but its been stalling out if you back off the throttle some, it starts fine and when bucking at full throttle it's fine so my question is, what could be making stall out?

The gas I use is non ethanol which was just bought over a week ago and mixed.

 

[dougand3]

Probably carb out of tune - Hi screw may need 1/8 turn richer (CCW) - if you mean stall is just barely off WOT. If stall is at much lower throttle position, could be Lo screw.

 

[redmanlcs]

Not to debunk the previous post, before adjusting the carb, check your air filter. Depending on age of saw it might be a hole or crack in the fuel line, or a bad carb to cylinder gasket, or the carb mounting screws may be loose. If it ran fine before I don't see the carb needing to be adjusted unless the adjustment screws are loose allowing them to turn from vibration. just my 02

 

[SpaceBus]

Agree with Redmanlcs, fuss with the carb last. It can be a real pain to get them in tune, so I avoid messing with them at all costs.

 

[salecker]

It's sound like a carb issue.
Spacebus,they are actually easy to tune.And you should learn how unless you plan on getting computer controlled saws.
If it was an air leak,like what was mentioned in redmanics post you would have a saw that races and has high idle because an air leak leans out your fuel mixture.
I would be starting with the carb myself,There are a bunch of utube videos about tuning a saw.
Clean the air filter
Start saw and let it warm up.
get the saw to idle with the idle control
adjust the low mixture to the point where the saw begins to speed up as you close it.
Now comes the part people hate...
Hold the saw throttle wide open,then adjust the high circuit open till it starts to stumble,close it till it races then open back up till it starts to sound like a 4 stroke engine,then i open mine up just a little more for insurance.
The saw should 4 stroke when wide open not cutting,then as soon as you begin to cut the sound of the saw should revert to a 2 cycle sound and sound like it's running clean.
Watch a few videos by the experts and give it a try.
This is a totally risk free thing to try. Befor you do anything you can record your settings and go back to them at any time.Just count the turns of the screwdriver to close the mixture screws record it and have fun.

 

[SpaceBus]

It's sound like a carb issue.
Spacebus,they are actually easy to tune.And you should learn how unless you plan on getting computer controlled saws.
If it was an air leak,like what was mentioned in redmanics post you would have a saw that races and has high idle because an air leak leans out your fuel mixture.
I would be starting with the carb myself,There are a bunch of utube videos about tuning a saw.
Clean the air filter
Start saw and let it warm up.
get the saw to idle with the idle control
adjust the low mixture to the point where the saw begins to speed up as you close it.
Now comes the part people hate...
Hold the saw throttle wide open,then adjust the high circuit open till it starts to stumble,close it till it races then open back up till it starts to sound like a 4 stroke engine,then i open mine up just a little more for insurance.
The saw should 4 stroke when wide open not cutting,then as soon as you begin to cut the sound of the saw should revert to a 2 cycle sound and sound like it's running clean.
Watch a few videos by the experts and give it a try.
This is a totally risk free thing to try. Befor you do anything you can record your settings and go back to them at any time.Just count the turns of the screwdriver to close the mixture screws record it and have fun.

I was probably a bit over the top, but really I just like to rule out things that don't have variables first. It's an easy change for the plug and filter, so a great first check.

 

[Corey]

Weak ignition, carboned up spark plug, water / moisture in the gas, poor idle adjustment, gummed up carb / fuel pump, improper carb adjustment for the season...combination of any/all of those.

You say it runs fine at WOT, so the fuel filter / air filter should not be an issue, but might not hurt to remove and blow it out / give it a good cleaning, too.

I'd probably start with a fresh spark plug and run some fresh ethanol/gas through the system. That would get the ignition side in top shape and the ethanol would help flush any water / varnish out of the system.

If still having problems, THEN you might try adjusting the low side carburetor mix screw and look for other problems deeper in the saw.

 

[thewoodlands]

Thanks for the replies everyone, hopefully I'll find out by the end of the week since I brought it to the local Stihl dealer. The 310 was my first good/real chainsaw purchase.

I did get the 028 Wood Boss out and she fired up nice so I'll be running that for limbing and bucking up some smaller stuff, I bought it from my neighbor for sixty dollars (that's what he wanted) it wasn't running when I bought it but a new spark plug and another seventy five dollars to have the Stihl dealer go through it and it's a nice saw.

It came with the original bar (14 inch, I think) with two chains but I bought a sixteen inch bar for it with some new chains a few years back.

 

[salecker]

I was probably a bit over the top, but really I just like to rule out things that don't have variables first. It's an easy change for the plug and filter, so a great first check.

There is not much variable about a carb tune.
If you count the turns to close the mixture screw,you can adjust it all you want then go back to exactly were you were before.
There has been many stories about some spark plugs being junk out of the box new.
Time wise,you can phug with the mixture screws faster then changing either the plug or filter.
The mixture screws are the most important adjustments on your saw.
Having them tuned wrong can wreck your saw.Temperature differences,altitude differences,mix differences can all effect the tune of your saw.Running it out of tune can melt your piston.
Knowing how to tune your saw can make the difference between coming home with a truck load of wood,or coming home with a few pieces and a burned up saw.
Just as important as knowing how to sharpen your chain properly.

 

[TreePointer]

Note that the 310 is from the 290-310-390 family of saws, so anything you encounter would also show up in discussions of the very popular 290.

 

[TreePointer]

Eliminate the spark arrestor as possible cause:

Pull the spark arrestor screen and clean it. Hold it with pliers and burn off all the crud/carbon deposits. Even a flame resistant grill lighter (torch style) can get it hot enough (cherry red) to clean the screen.

 

[thewoodlands]

Eliminate the spark arrestor as possible cause:

Pull the spark arrestor screen and clean it. Hold it with pliers and burn off all the crud/carbon deposits. Even a flame resistant grill lighter (torch style) can get it hot enough (cherry red) to clean the screen.

When I dropped it off I did mention that but he didn't seem real concerned about that, I'll have him clean or put in a new one when I call them tomorrow.

 

[TreePointer]

When I dropped it off I did mention that but he didn't seem real concerned about that, I'll have him clean or put in a new one when I call them tomorrow.

Unless it's torn, you don't need to spend $$ on a new one. It's just a piece of stiff steel mesh. Easy test to see if it's an issue is to run the saw without the arrestor.

 

[thewoodlands]

Unless it's torn, you don't need to spend $$ on a new one. It's just a piece of stiff steel mesh. Easy test to see if it's an issue is to run the saw without the arrestor.

Would you spray the nuts with anything before you loosen them up?

 

[TreePointer]

Would you spray the nuts with anything before you loosen them up?

Muffler fasteners should come off without much issue. Just make sure to use a properly fitting driver/socket to remove them.

 

[thewoodlands]

Muffler fasteners should come off without much issue. Just make sure to use a properly fitting driver/socket to remove them.

Thanks @TreePointer , I'll be cleaning up the old 028 WoodBoss tonight and hopefully it will get some work in this week or weekend. The original bar on the 028 looks like a 11 or 14 inch bar.

 

[TreePointer]

Just to clarify, the nuts/fasteners on these mufflers may take a bit of effort to get them moving initially, but it's nothing that your average length 1/4" socket handle can't handle in my experience.

 

[thewoodlands]

Just to clarify, the nuts/fasteners on these mufflers may take a bit of effort to get them moving initially, but it's nothing that your average length 1/4" socket handle can't handle in my experience.

I just came in from cleaning up the 028 wood boss, when I started cleaning it I flopped the gas tank side down an I have a small leak so I'm thinking it needs a rubber washer because the gas cover is pretty new.

I'm picking two more of these up so I have a enclosed spot for my WD-40 instead of a plastic coffee can, one of these will be an extra. The top comes off so you have a big opening and it has a plastic screen that sits in there if you want to use it to drain oil from a filter.....if you're using it for oil.

 

[thewoodlands]

Probably carb out of tune - Hi screw may need 1/8 turn richer (CCW) - if you mean stall is just barely off WOT. If stall is at much lower throttle position, could be Lo screw.

Probably carb out of tune - Hi screw may need 1/8 turn richer (CCW) - if you mean stall is just barely off WOT. If stall is at much lower throttle position, could be Lo screw.

I picked the 310 up today, the limiter caps were off when I brought it in so he thought that could've been the problem so it was tuned up with the caps back on. I don't have the tools to take the caps off so I'm not sure what happened.

He also said he put a new Carburetor in it, he said it should be fine so I'll use it tomorrow.

I ran it today (6/13) but after about 15 - 20 minutes it started the same chit.

 

[redmanlcs]

no freakin way

 

[redmanlcs]

has to be weak ignition. Replace your ignition control thing a ma bob. I mean air fuel spark... air is usually a freebie... fuel well you got a "new carb".. so if it was fuel related.... with a different carb or at least one cleaned...... you would think it would act somewhat differently.. spark.. do you think your coil could be bad?.. getting hot and creating a weak spark?... have you checked how your sparkpug is firing? I like to see a nice fat blue spark.. not a weak thin yellow looking spark... .. I usually test by taking the plug out.. connecting it to the sparkplug wire and cranking it with the the tip of the plug against the metal head to ground it. It pulls easy doing this as there is no compression. I don't know how the ignition systems works on that saw tho... shouldn't be anything too exotic.. just my oh two

 

[SpaceBus]

Redman might be onto something. How hot was it yesterday? Could be a temperature thing. In the summer cutting thread some folks mentioned their saws running poorly in the heat. I noticed my new to me 346 doesn't idle as smooth after cutting in the sun when it's 75f+ outside. No issues while in the shade, but it probably needs a carb adjustment either way. Download the service manual for your saw if you can find it, there might be some info in there.

The older I get the more the dealer does nothing for me. Thankfully my local Stihl/husky dealer has some kind of saw Jesus in the service department and he swapped my drive sprocket in minutes. Usually though I find that dealing with things myself works best. Nobody will take care of your equipment the way you will.

 

[thewoodlands]

has to be weak ignition. Replace your ignition control thing a ma bob. I mean air fuel spark... air is usually a freebie... fuel well you got a "new carb".. so if it was fuel related.... with a different carb or at least one cleaned...... you would think it would act somewhat differently.. spark.. do you think your coil could be bad?.. getting hot and creating a weak spark?... have you checked how your sparkpug is firing? I like to see a nice fat blue spark.. not a weak thin yellow looking spark... .. I usually test by taking the plug out.. connecting it to the sparkplug wire and cranking it with the the tip of the plug against the metal head to ground it. It pulls easy doing this as there is no compression. I don't know how the ignition systems works on that saw tho... shouldn't be anything too exotic.. just my oh two

That is what will be changed next, I have plenty of stacking to do so hopefully they'll keep it and run it through some wood for about 20 minutes, it usually runs fine for about 20 minutes and then the problems start.

 

[TreePointer]

Maybe I missed it, but I haven't seen the idle speed screw (labeled "LA") discussed here. Many times this screw needs to be adjusted one last time after the high and low speed jets are set.

While idling, turn this screw clockwise until chain starts moving, and then back off (counterclockwise) a quarter turn (as owners manual suggests). Maybe a quarter turn is too much? Then try one-eighth.

 

[SpaceBus]

Maybe I missed it, but I haven't seen the idle speed screw (labeled "LA") discussed here. Many times this screw needs to be adjusted one last time after the high and low speed jets are set.

While idling, turn this screw clockwise until chain starts moving, and then back off (counterclockwise) a quarter turn (as owners manual suggests). Maybe a quarter turn is too much? Then try one-eighth.

My 346 probably needs a tune. It came from the other side of the continent.