Problem with Stihl 028

[ferris076]

Hello guys,
i get a Stihl 028 with one Problem.
The saw make very strange noise when i pull the trigger, i have no idea what is it.

The saw makes a strange clatter when accelerating, this disappears with higher rpm‘s.

Settings on the carburetor will not change that.

what could that be?
please look at the video

 

[HarleyT]

Take off the bar and chain, and put up a pick of your sprocket, and also a pic of the bottom of the chain.

 

[Conquistador3]

Try running it without chain and bar.

Also check the brake band. I've had an old Echo in the past with a similar issue: it was caused by at least a decade of solified sawdust, sap, resin and God knows what else between the brake band and the sprocket drum. It took two hours to clean that mess... on top the time to check everything else.

 

[drf255]

Pull carb. See how wet filter is. Peak down at intake skirt on piston. Change spark plug.

Sounds like lots of blowback to me.

Also, check that crank key hasn’t sheared.

 

[Wood Doctor]

Try running it without chain and bar.

Also check the brake band. I've had an old Echo in the past with a similar issue: it was caused by at least a decade of solified sawdust, sap, resin and God knows what else between the brake band and the sprocket drum. It took two hours to clean that mess... on top the time to check everything else.

I agree and remember that this saw is at least 20 years old. Clean up the entire clutch and brake band area before you do anything else and run it without the bar and chain. Then report back.

 

[HarleyT]

Sounds like a worn out sprocket grinding off the drive links!!

But hard to tell over the internet!!!!

 

[Wood Doctor]

Sounds like a worn out sprocket grinding off the drive links!!

But hard to tell over the internet!!!!

That could be the problem also, especially if running without the B/C eliminates most of the the noise. Sprocket may be shot. I replaced one about three years ago that was eating up chain teeth like a cement mixer.

 

[HarleyT]

Most times the notch in the sprocket is cut so well, it looks like it was made that way!!!
I just pull a new one off the shelf to show the customer.

 

[rd35]

Wow that thing coasts a lot. I'd pull off the starter and top covers and blow that thing out with compressed air. I'm betting it is so packed with dust and dirt that the flywheel cannot blow air across the cylinder (or anywhere else for that matter). Not sure about the funny noise, but I wouldn't run it that way if it is clogged up.

 

[ferris076]

@HarleyT
@rd35
I run the saw without b/c , the noise is still there.
Breakband looks ok, but i can‘t remove the sprocket.
The problem is the plastic gear from the oil pump, how can i remove this gear?

I can lift it for about 10mm but that‘s it.
Where is the trick to remove this

 

[CsClimbr]

@HarleyT
@rd35
I run the saw without b/c , the noise is still there.
Breakband looks ok, but i can‘t remove the sprocket.
The problem is the plastic gear from the oil pump, how can i remove this gear?

I can lift it for about 10mm but that‘s it.
Where is the trick to remove this

Should pull right off as far as I can remember, maybe twisting in one direction or the other. It’s been awhile since I’ve got into an 028 though

 

[Conquistador3]

@HarleyT
@rd35
I run the saw without b/c , the noise is still there.
Breakband looks ok, but i can‘t remove the sprocket.
The problem is the plastic gear from the oil pump, how can i remove this gear?

I can lift it for about 10mm but that‘s it.
Where is the trick to remove this

To remove the gear, pull it slowly while you rotate it slowly but firmly clockwise. There's a rubber seal on the shaft that may put up far more resistance than you'd expect from such an insignificant piece of rubber. If it puts up more resistance than acceptable, use a small screwdriver or one of those smartphone plastic prying tools to lift the gear while rotating it.

 

[Okie]

Can you feel any unusual vibration?

If you don't see anything on that side go to the other side and inspect.
I would probably eventually pull the starter side cover and the spark plug out and see if I could FEEL a bump or rough spot as I turned the flywheel by hand. With the spark plug out all should be a smooth rotation of the flywheel by hand.

I suspect that you can feel a rough spot when rotating by hand with spark plug out.

I would stop piss reving the engine until I found the source of it's sickness.

Hopefully it's not a bearing.

Might be something chewing on the backside of the flywheel. If so all hell is going to break loose eventually.

 

[pioneerguy600]

That noise reminds me of a wrist pin bearing about to explode, just keep piss revving that saw,it should fix itself real soon...

 

[Okie]

That noise reminds me of a wrist pin bearing about to explode, just keep piss revving that saw,it should fix itself real soon...

My thought also about bearing noise and it fixing itself due to piss revving.

 

[Huntaholic]

I just got done completely rebuilding a ms461 that had a noise like that in it. I tried eliminating all the possibilities before tearing it down since a Stihl is supposed to last forever or at least longer than the 6 months Ive been running it. Turns out it was the big end bearing on the connecting rod. Of course that meant a complete and total rebuild. Hope your luck is better than mine but the sound is the same as what mine was doing.

 

[rd35]

Hey ferris076
I believe you have to pull the brake band cover off the saw before you can remove the sprocket on that model. Maybe somebody can correct me but that is how I though that series of Stihl saw worked. The clutch drum is under that cover. So, the entire cover has to be removed first.

 

[BROX]

There is also a snap ring around the sprocket that has to be removed before the plastic cover comes off.