Stihl MS 660 magnum reliability

Chain5moker

New member
Joined
Jan 31, 2026
Messages
1
my buddy used to be a die hard Stihl guy. his old AV 028 ran like a champ for more than 20 years, and his 044 was a beast.
but he recently bought an MS 660 magnum to use as a personal sawmill, and it's been a total nightmare from day one
it wouldn't even start when it was brand new, and things only went downhill from there
he’s pampered this saw for years, hoping it would be a lifetime tool, but between the mechanical failures and poor support, he’s about ready to jump ship. it’s a huge investment to have sitting dead in the shedi
for those of you who run big saws for milling or heavy logging, what’s the best large saw on the market today?
should I tell him to look at other shainsaw, like a Husqvarna 592 XP or something from Echo, or is there a way to save this 660?
 
My friend went through a similar ordeal with a brand new big saw.
After hitting the shop a dozen times, he decided it was time to cut his losses and switched to a Husqvarna 592 XP.
That thing runs like a dream, no hassle at all.
Sometimes, it's just easier and cheaper to move on than deal with a dud.
 
I also gave the MS 660 a shot, and let me tell you… it was a disaster from the start. If he’s really into milling, I’d suggest going with a Husqvarna or Echo. Big saws need solid support, and the XP series just fires up and works like it should. Sure, he could try to fix the 660, but it’s going to be a long and frustrating journey.
 
After two decades of loving Stihl, switching to a giant 660 isn’t easy.
My recommendation? Go with the Husqvarna 592 XP or an Echo for heavy milling.
If he sticks with the 660, it's going to drain his time and patience.
Sometimes, hanging onto a problematic saw ends up being more costly than just investing in a reliable one from the start.
 
Not sure why 066s or 660s seem so problematic. Had one that seemed indestructible and ran for years doing heavy duty every day cutting. But it's the only one of 5 I've had that didn't lock up. Now I wasn't the one mixing the gas. Always made me wonder if there wasn't something about the heavy use at high rim for extended periods of time that the mix should have been more oil to gas. Ive got 2 sitting on my shop floor, both with scored pistons. With that said, I don't think it's a Stihl issue, I believe it's a model issue because I have a 880 and at one time an 088 (stole from me) that were dedicated power heads on a mill. No issues with either. The 088 had a ton of hours on it and the oiler got weak and I had bought a replacement for it, just hadn't put it on yet. Both saws start great.
Any manufacturer can have problems. I once went through 5 husky 562s with the magnesium case in 6 months , every one locked up and every one, when taken apart revealed a carb to head deformation where dirt was getting past the gasket. One lasted a mere 3 weeks, none made it past 3 months. Husky bulled up and quit warrantying them so I moved to a different model, 365 I believe and those 5 all lasted 2 -4 years with heavy use.

Its almost impossible to have too much power when milling. If I had a strapping young boy, I'd have 2 power heads on my mill and put him on the other end. Get the biggest saw weight wise you want to lift and have at it. I'm 61 and can still handle the 88 with a 32" Granberg which has a 54" bar total length to it.
 
The biggest issue with an saw on a mill is having it rich enough and allowing it to warm up a little before hogging in.
If I had a dedicated mill that was used daily, I would have an 880 or go hydraulic. Good place for 404 chain.
Like having a big block Chevy in an SS Chevelle or a dump truck. One will shine on a drag strip, one will pull stumps and last a few 100,000 miles.
Not a proponent of mods, but a 660 on a mill would have a better flowing muffler, slightly richer mix, air filter checked daily (or more) and never be forced. The carb would be on the richer side on the high screw.
You don't want a hot car for short blasts, you want a torquer that will last.
 
Not sure why 066s or 660s seem so problematic. Had one that seemed indestructible and ran for years doing heavy duty every day cutting. But it's the only one of 5 I've had that didn't lock up. Now I wasn't the one mixing the gas. Always made me wonder if there wasn't something about the heavy use at high rim for extended periods of time that the mix should have been more oil to gas. Ive got 2 sitting on my shop floor, both with scored pistons. With that said, I don't think it's a Stihl issue, I believe it's a model issue because I have a 880 and at one time an 088 (stole from me) that were dedicated power heads on a mill. No issues with either. The 088 had a ton of hours on it and the oiler got weak and I had bought a replacement for it, just hadn't put it on yet. Both saws start great.
Any manufacturer can have problems. I once went through 5 husky 562s with the magnesium case in 6 months , every one locked up and every one, when taken apart revealed a carb to head deformation where dirt was getting past the gasket. One lasted a mere 3 weeks, none made it past 3 months. Husky bulled up and quit warrantying them so I moved to a different model, 365 I believe and those 5 all lasted 2 -4 years with heavy use.

Its almost impossible to have too much power when milling. If I had a strapping young boy, I'd have 2 power heads on my mill and put him on the other end. Get the biggest saw weight wise you want to lift and have at it. I'm 61 and can still handle the 88 with a 32" Granberg which has a 54" bar total length to it.
That’s some solid real-world experience you’ve got there. Appreciate all the specifics it really helps clarify things. It seems like how you use it, set it up, and the fuel mix are just as important as the brand on the outside.
 
The biggest issue with an saw on a mill is having it rich enough and allowing it to warm up a little before hogging in.
If I had a dedicated mill that was used daily, I would have an 880 or go hydraulic. Good place for 404 chain.
Like having a big block Chevy in an SS Chevelle or a dump truck. One will shine on a drag strip, one will pull stumps and last a few 100,000 miles.
Not a proponent of mods, but a 660 on a mill would have a better flowing muffler, slightly richer mix, air filter checked daily (or more) and never be forced. The carb would be on the richer side on the high screw.
You don't want a hot car for short blasts, you want a torquer that will last.
Well said. A brilliant way to say it. Taking the time to warm up, enjoying those rich sounds, and allowing the saw to work its magic instead of pushing it makes all the difference. Love the comparison between the big block and the dump truck.
 
066, 660 and larger saws may show a cold lean seize. This occurs when the piston gets no time to warm up in the bore and will score, usually on the sides. Stihl has warned against this for years, especially in cold weather. Have seen it on other brands of large saws.
Yes, even saws need to warm up a little.
 
Back
Top