Premature bar wear mystery on new MS 661 C-M

[IMSkywalker]

A derecho storm on 8/10 has left countless downed & damaged trees in my area. Last week I purchased a MS 661 to add to my Stihl collection to speed the processing. I'm running a 25" bar with Stihl RS chain cutting oak up to 32" dia. thus far, I only cut wood weekends and evenings. Starting with full tanks of fuel and oil, the saw ran & cut great on the first cuts then started having trouble cutting straight. Checked chain tension OK and chain still sharp, oil in tank. I noticed the bar paint was wearing at the bottom after going through 1 tank of fuel, blamed it on hard wood and maybe poor quality paint finish. The next evening checked chain, tension, topped off oil ran a partial tank, still not cutting straight, blamed it on the wood grain issues. On the third day, I did my pre-cut checks and discovered the chain was able to pivot dramatically side-to-side in bar on the bottom side. It would pivot further away from the power unit (the saw was cutting to the right). I also noticed a large metal burr where the chain rides on the bar bottom opposite the power unit. The top of the bar seemed fine (chain side play near normal), so I flipped the bar and the saw cuts straight again, at least temporarily, I've only run a partial tank of fuel since. I've run less than 3 tanks or fuel through the saw total.

This is dumbfounding, I've never had any trouble with my many Stihl products. Also, this saw and bar were made in Germany, should be very high quality standards. The bar look like sh** already.

In question:

Oiler: Bad or inconsistent Ematic oiler system? Oil sling test seems to show system in functioning, at least at times. Also, since I am adding oil to the tank consistently the oil must be going somewhere. The bar & chain adjusting screw is set to E (Ematic)(rotated against the Oil Adjuster Limiter pin). I performed a oil sling test pointing the bar nose at sheet of paper for 10 seconds at full throttle and compared to my 1994 026 Pro saw. See image.

Bar: Bad bar from the factory? Did the bar get assembled incorrectly? Did on side plate miss a heat treat hardening process? Currently the chain tooth can move laterally 5/32" on the bad side and 2/32" on the good (10" from the power unit).

Chain: Doesn't seem like this could cause premature bar wear.

I use the same Echo premium bar & chain lube in my 026 Pro saw (I purchased new in '94 and has run around 60 tanks of fuel and has the original bar). See pictures for comparison.

Though not the case, the dealer will likely say the saw was run out of oil. Even if I install a new $80 bar I'm not confident the problem will be solved. I'm posting for advice prior to contacting the dealer from which the saw was purchased.

A lot of saw experience on this site. I'd very much appreciate any advice.

Mark

 

[Short timer]

Not saying this is the cause, but that limiting pin can be pushed in with a punch and hammer to get more travel out of the control bolt for more oil flow, it’s explained in the owners manual.

As far as your problem, I would first check to make sure you have the correct chain installed on the bar. (Gauge)

Also, if your chain is “tensioned” how you run it as shown in the pics, it’s extremely loose. It shouldn’t be sagging on the bottom like that, especially cold.

 

[Short timer]

@pioneerguy600 probably could move this out of the “sticky” section for you so it gets more views.

 

[Leeroy]

Both bars doing the same thing?
Strange looking chain in top pics.

 

[Short timer]

Both bars doing the same thing?
Strange looking chain in top pics.

Top pic is his 026 with .063 .325 low kickback chain.

 

[Leeroy]

Top pic is his 026 with .063 .325 low kickback chain.

Ten4!
I will say the side plate on the chain in question looks poor., and would think this is the problem.

 

[Short timer]

Ten4!
I will say the side plate on the chain in question looks poor., and would think this is the problem.

Might be an illusion if you‘re looking at the top side, I see what you’re saying but if you look at the bottom side, I don’t see the same thing.

I’d dress the burr on the rail he’s talking about, post a pic of the markings on the bar and chain, if that matches, as in not a .058 bar with a .050 chain, then tension it tighter and see how it does. Try a different chain too.

 

[Short timer]

Btw stihls paint sucks on their bars now, don’t use that as an indication something is wrong. Blame the EPA for that.

 

[RED-85-Z51]

Maybe 050 chain on an 063 bar?

Sent from my LM-G820 using Tapatalk

 

[PV Hiker]

can't read the bar info stamped, you left us wondering what bar you have and chain if it is proper sized. More information needed.

 

[BradSt]

If you zoom in on the bar laser etching, I can see it says 1.3mm, which is .050. It appears to be a 3/8 chain. I initially thought mismatch as well, but now I don't think so.

Am I the only one who thinks the 10 sec oiling test looks a little light? I say, push the pin in, and run it at true max oiling, and see what happens. In my experience with Stihl ES bars, they lose paint like that when they get hot. Yes, they will eventually lose paint along the rail, but IMO, it isn't normal in 3 tanks. None of mine have ever done that, that quickly.

 

[Trdoldtreecutter]

I know when we were cutting around mt. St hellen the ash was death on bar life. You say these logs were from a flood? I’m thinking you might be experiencing some similar problem

 

[MacAttack]

Maybe 050 chain on an 063 bar?

Sent from my LM-G820 using Tapatalk

Yeah Id measure that chain with a caliper and confirm the gauge.

 

[dmb2613]

Without it being in my hand I can only guess, How often do you sharpen the chain? No way can you have 2 to 5/32 side play
5/32 would be close to 4.0 mm plus the original width of the bar

 

[IMSkywalker]

Btw stihls paint sucks on their bars now, don’t use that as an indication something is wrong. Blame the EPA for that.

Thanks for the info. I wish I'd have purchased several bars back in the 90's for stock, must be tougher paint and steel. Also, pictures show warm saws prior to chain adjustment. I set cold chains at 1mm.
Also, I should have noted the 026 is running Stihl RD3 Carbide chain. It does look different.

It appears the 661 bar and chain are matched correctly. The bar is etched 1.3mm/0.050". Actual caliper measurements below verify size and dramatic wear.
Chain drive link measurement: 0.047-0.049"
Bar Upper groove width: 0.055"
Bar Lower groove width: 0.066"

I'm tempted to put on a new bar & chain but I'm not confident the Ematic oiler system is functioning properly & if defective, could fail completely. Since this is a brand new saw I would like to make sure this system is working correctly to specification while under warranty.

 

[IMSkywalker]

Maybe 050 chain on an 063 bar?

Sent from my LM-G820 using Tapatalk

Thank you. It appears the bar and chain are matched correctly. The bar is etched 1.3mm/0.050". Actual caliper measurements below verify size and dramatic wear.

Chain drive link measurement: 0.047-0.049"
Bar Upper groove width: 0.055"
Bar Lower groove width: 0.066"

 

[IMSkywalker]

If you zoom in on the bar laser etching, I can see it says 1.3mm, which is .050. It appears to be a 3/8 chain. I initially thought mismatch as well, but now I don't think so.

Am I the only one who thinks the 10 sec oiling test looks a little light? I say, push the pin in, and run it at true max oiling, and see what happens. In my experience with Stihl ES bars, they lose paint like that when they get hot. Yes, they will eventually lose paint along the rail, but IMO, it isn't normal in 3 tanks. None of mine have ever done that, that quickly.

Thank you for your input and insight.
It appears the bar and chain are matched correctly. The bar is etched 1.3mm/0.050". Actual caliper measurements below verify size and dramatic wear.
Chain drive link measurement: 0.047-0.049"
Bar Upper groove width: 0.055"
Bar Lower groove width: 0.066"

I agree the 026 appeared to output more than double the 661. I'm not trusting the Ematic oiler system is functioning properly. Bar paint does wear, however I can't imagine it is acceptable for the bar to look this worn for around 1 hour of cutting. I only refilled the tank 3 times, each time it was not completely empty.

 

[IMSkywalker]

Without it being in my hand I can only guess, How often do you sharpen the chain? No way can you have 2 to 5/32 side play
5/32 would be close to 4.0 mm plus the original width of the bar

Thank you for you input. I only sharpen when I notice a change in performance or teeth no longer feels "sticky" sharp.
It appears the bar and chain are matched correctly. The bar is etched 1.3mm/0.050". Actual caliper measurements below verify size and dramatic wear.
Chain drive link measurement: 0.047-0.049"
Bar Upper groove width: 0.055"
Bar Lower groove width: 0.066"

 

[IMSkywalker]

I know when we were cutting around mt. St hellen the ash was death on bar life. You say these logs were from a flood? I’m thinking you might be experiencing some similar problem

Interesting. Thank you for the info. The logs are not from a flood they are from a wind storm (a rare "inland hurricane" called a Derecho storm). If any soil, I keep on outfeed side and or use the 026 with RD3 carbide teeth.

 

[Jhenderson]

1st. If it cuts to one side your chain needs to be properly sharpened. One side is sharper than the other. 2nd. Your bar has a burr on the bottom because you’re pushing on the saw rather than the chain feeding itself through the wood. That’s the second indication your chain is dull.