mitch95100
Saw Nut
Does anyone know What are the general tuning specs for the Stihl Ms 660? Looking for the RPM specs for full and idle
Thanks
Thanks
Tuning Specs For Stihl MS660
- Thread starter mitch95100
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forestryworks
Addicted to ArboristSite
Idle is around 2,500, give or take.
On the high end, 13,500, again, give or take.
Always tune in the cut.
Do you have a service manual? PM me if not.
On the high end, 13,500, again, give or take.
Always tune in the cut.
Do you have a service manual? PM me if not.
Here is an RPM chart:
Maybe a Little Lower?
Good discussion here.
Some loggers don't like to run 14,200 RPM on their 660s. I usually set them back about 13,400 RPM for the guys running big bars. It could be that they want more life out of the engine and are afraid to run them higher for fear of premature burnout. Who knows? I do what they want. Idle at 2,500 RPM seems to keep the chain from creeping very much and the engine will hold it.
Good discussion here.
mitch95100
Saw Nut
Yeah Im definatley not looking to burn my engine up!
Tzed250
Addicted to ArboristSite
Forget the tach. Learn to tune the H needle by ear. That way you know the saw is getting what it needs.
mitch95100
Saw Nut
Not on a 700 dollar saw
forestryworks
Addicted to ArboristSite
Tune by ear, but in the cut. Tach is good for baseline settings.
Tzed250
Addicted to ArboristSite
That right there is funny !!!!
I tune my $1100 dollar saw by ear.
BTW, don't know of many pro fallers that carry a tach into the woods with them.
RiverRat2
Serio Tree Freak
I think my ported 066 works best just when it's starting to 4 stroke good then cleans up nice in the cut,,, it's usually wearing a 36" bar but with that same tune and wearing a 28" bar you had better Hang on,,, as far as RPM's it was still 4 stroking @ 14K right after I ported it,,, I havent checked it in a long time couple of years,,, but I gonna,,, I let nephew borry it the other day and when I went and got it back I notced the exhaust deflector looked white instead of my usual camel/tan color,,, I gently nudged the H screw in and it was setting on 3/4,,,, Grrrrrrrrrrrrrrr then I got hot!!!!!!
I pulled the muffler cover, rolled it through a couple of cycles and the piston looked fine,,, put cover back on, the H back to 1+1/8 out,,,Put my saw back in the truck,,, called my nephew and gave his ear a good dose of For what,,,, and What for,,,
I pulled the muffler cover, rolled it through a couple of cycles and the piston looked fine,,, put cover back on, the H back to 1+1/8 out,,,Put my saw back in the truck,,, called my nephew and gave his ear a good dose of For what,,,, and What for,,,
Tuning by ear is the safest, quickest, and cheapest method going, as long as you've learned what to listen for?
mitch95100
Saw Nut
Ill take a vid for you guys and you tell me if its right ill try my best!
Slamm
Addicted to ArboristSite
Wow, I sure wouldn't let my 660's be tuned to 14,000+ for cutting, that is too high and the saw will fall on its face more in the cut. Better to tune a little richer, than leaner, as those lean saws can't handle any sort of miss handling or lugging. I imagine for cookie cutting that the leaner settings seem to work/win by a few seconds, as those are the types that seem to like the leaner settings and or think that its of some mystical benefit, when in reality the saw will many times hold a lower rpm in the cut of any worth.
Sam
Sam
treestologs
New Member
jets
hi guys sorry to interupt but im new on here and struggling to open a thread but i am currently running ms650 that was piston damaged wen i bout it so i rebuilt it with a ms660 pot and piston with no gasket for a pinch more compression but i just a lil conserned on wether i need to change the the jets or not ?? i know you can alter the mixture a little . any feed back would be great thanks rich
hi guys sorry to interupt but im new on here and struggling to open a thread but i am currently running ms650 that was piston damaged wen i bout it so i rebuilt it with a ms660 pot and piston with no gasket for a pinch more compression but i just a lil conserned on wether i need to change the the jets or not ?? i know you can alter the mixture a little . any feed back would be great thanks rich
Tzed250
Addicted to ArboristSite
Did you actually measure the squish? The later 660s have notoriously tight squish from the factory. My 660 would not even turn over with the base gasket removed.
indiansprings
Firewood Purveyor
Under no circumstance is a dead stock 660 going out of our shop above 14k. With out knowing the quality of fuel/mix and care and useage that the average joe is going to be doing it is a recipe for diasaster/toasted saw. I always use a tach for a baseline, and then clean it up by ear if needed. There are a few on here I would trust tuning without a tach but I'd say 90%+ couldn't guess within a 1000 rpms, it is an art that comes with expeirence and years of doing it, not something the occaisional user should attempt. It depends on the saw but idle is usually set somewhere around 2750-3100 and we won't send them out above 13,500. We've got one or two customers that get them set around 13k, but it is due to how they abuse the heck out of the saws and the cheap gas (test 13% ethanol) and cheap mix they use. When tuning for joe public you tend to tune on the conservative side, my saws are a whole different tuning set up, because they get 91 oct non ethanol and Ultra and air filters are cleaned after each use, sharp chains are the norm, not the exception.
Well, at least this post is consistent with what I said back in Post #5. Maybe we are getting somewhere. I've set the high-end RPM on my "new" rebuilt MS660 at 13,400. It's idling very nicely at 2500 RPM with a 32" bar and chain on board. Seems comfortable there. No significant chain creep, and that's important. I'm ready to cut a bunch of wood, and this rebuilt 660 will kick butt.
