Blade always running

   / Blade always running #1  

NCMau

Gold Member
Joined
Nov 5, 2009
Messages
293
Location
NC
Tractor
MF 202/Ford 8N
My old Stihl mod 015 has been a great saw over the years. But since I replaced the clutch, the blade always runs at idle speed. I am assuming that the clutch is at fault because it is always engaged regardless of the low speed/idle adjustment. When I try to adjust the low speed to a minimum, the engine stops.
The clutch I ordered is supposed to be the correct part and it is branded Stihl. Can the carburetor be at fault? Any suggestions?
 
   / Blade always running #2  
Chainsaws don't have blades.

Unless the clutch is defective, the reason for the chain moving at idle is simply that the idle is set too high.
 
   / Blade always running #3  
If the clutch does not disengage even at low engine speeds it's a problem with the clutch.
Sounds like there was a problem with the clutch installation or the wrong part was used. It's unlikely that a new part would be defective but it does happen. Does the clutch spin freely when the saw is off? Either way you should take it off and figure out what's wrong. A chain that doesn't stop is dangerous.
 
   / Blade always running #4  
I'm doubting its a problem with the new clutch...More than likely the old clutch did not engage well, so when tuned they increased idle speed for throttle response. Now that the new unworn clutch is in you can back the idle speed down until the chain doesn't move at idle anymore. Very simple to do especially on the older saws. You should see 3 holes, H, L, I. Start the saw let it get completely warmed up and then turn the I screw counter CW until the chain stops moving at idle. On your stihl, the H and L should be side by side and the I below them.
 
   / Blade always running #5  
The OP said that the clutch is still engaged even when he turns the idle down so far that the saw stalls. The low speed mixture could be so far off that the saw won't run anywhere close to idle but it'd have to be really far off to make the saw run so fast that a clutch in good shape stays engaged. And it would be obvious that the saw isnt' idling at that point. Also he said that the problem started when he replaced the clutch. When something doesn't work right after you make a change, the first place to look is the thing you changed.

If you have messed with the mixture so much that you're lost, you can go back to the factory recommended starting point (often 1 turn out on Stihl) and go from there. On my Stihls the idle screw is marked 'LA'.
 
   / Blade always running #6  
Does the "blade" stop when the saw is at idle and engaged with some wood or does the engine stall?
 
   / Blade always running #7  
Its a chain that runs on a bar attached to the head of the saw. The chain should not move at correct idle, after warmed to operating temp and at proper mixture. You need to figure out where the saw is set at and set it up properly as to mixture and idle, as already mentioned by others.
The bar needs to be straight with no burrs in the track where the chain rides, and not gummed up or pinched either.
The clutch mechanism needs to be the correct one for your model saw, and the chain must match the bar and saw it's used on, as well as being properly tensioned, but not too tight, or loose. Too tight a chain will damage the engine bearing when the saw cools, and the chain should be loosened after being run to reduce this risk of damage. This is stated in one of the various Stihl manuals, I've owned over the years.
So, after having made all the adjustments suggested so far, if you still have a running chain at idle, your carb's functional ability to reach correct idle may be compromised by any number of issues.
Report back where you're after doing what's already been suggested, then let's see where you're at.
 
   / Blade always running #8  
The cutting part of a chainsaw:

A chain with extended upper links that culminate in teeth that are sharpend to form a blade that the chain pulls through wood. It is guided/supported by extended lower links that will fit in a slot of a guide.

A Bar: dat's the place you visit after a day of guiding blades through wood and where pain reliever may be purchased.
 
   / Blade always running #9  
The cutting part of a chainsaw:

A chain with extended upper links that culminate in teeth that are sharpend to form a blade that the chain pulls through wood.


No, it's sharpened to form a tooth.

There is no "blade", and all the stubborn ignorance in the world won't make it a blade.
 
   / Blade always running #10  
My 372XP pulls the chain pretty fasts once I first start it up. If I put the chain brake on you can hear it put the engine under load. After I've made a cut it'll idle without moving the chain. BTW, the correct terminology is a chain. I'm not sure why that matters anyway.
 
 
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