MS660 tuning for milling

[JELIII]

I have a relatively new MS 660 that I was planing to put on a 48" Alaskan. What do I specifically need to do to try and prevent damaging the saw. I realize after reading a number of posts here and on other sites that I should probably start looking for a larger saw for this size mill, but I have both at this point and would like to try and make the most of what I have. In particular I am not sure I completely understand the carb adjustment instructions in the manual and based on what I have read I want to make sure I have it set a bit rich. I have read the procedures desired in Malloff, but I am nervous to even try to adjust it until I am clear on which way I should be turning the high jet. The manual talks about going 3/4 of a turn for the initnal setting, but the screw only has 3/4 of a rotation of total travel. Should I be modifying the muffler? This forum is a great help to all us newbies! Thanks for sharing the knowledge

 

[mtngun]

To richen the high, turn the jet out (counter clockwise).

To lean the high, turn the jet in (clockwise).

Sounds like your carb has limiter caps. You might want to pull them, cut off the limiting tab, and then reinstall them sans tab. Often they are destroyed in the process of removing them, so it may be just as well to buy replacement limit caps from the dealer.

Assuming you have the newer style muffler with one solitary exit hole, then yes, I'd suggest enlarging that one exit hole (while retaining the spark screen) and also drilling a couple of holes in the inner cage.

It takes a while to learn to tune a saw by ear. Madsen's has a good tutorial. saw tuning

I've been trying to tune by ear for several years, and I'm getting better at it (I'm somewhat tone deaf) but sometimes I still don't trust my ears, especially on a saw with an effective muffler. A tach provides a nice sanity check for us tone deaf types.

 

[woodsrunner]

I have a relatively new MS 660 that I was planing to put on a 48" Alaskan. What do I specifically need to do to try and prevent damaging the saw. I realize after reading a number of posts here and on other sites that I should probably start looking for a larger saw for this size mill, but I have both at this point and would like to try and make the most of what I have.

I would not be worried about a bigger saw just yet. Your mill will adjust "down" to a smaller bar. I run a Husky 395 with a 42 inch bar with no problems. I think you will be fine with the 660. Especially since you are just getting started. Learn and get accustomed to the whole process with what you have and then you will know better how to proceed to the next level.
BTW welcome to the crazy world of CSMing!

Scott

 

[ShoerFast]

Mof-mod it, trim off the tabs of the limiter caps run it fat-rich, counter-clockwise, very possible slightly over a full turn out but don't go by amount of turns, that's just a reference.

Muf-modding will allow it to run cooler, as well as a slightly fat carb setting.

Keep your chain sharp and don't crowd-force feed it much, let the chain do the work.

Going from a good tan color plug to more of a coco-color is fine for longevity.

In the long run....

It's better the plug, then the jug!​

 

[excess650]

I would suggest the dual port muffler, fuel/oil mixture at 40-1, and tuning for 11,000K max rpm.

My own milling saw (066)has a Bailey's big bore kit:spam: and definitely has more grunt:chainsawguy: than my "higher than stock compression" 660.

Tuned and fueled as suggested, I've milled in 90*F temperatures without engine issues. The clutch has taken a beating, but its a wear part.opcorn:

 

[JELIII]

Can someone give me more details on what I need to do t to the muffler, or am I better off spending the 120 on a dual port?

I will remove the tabs you are describing from the carb adjustments tomorrow.

Thanks for all the advice.

 

[BIG JAKE]

Can someone give me more details on what I need to do t to the muffler, or am I better off spending the 120 on a dual port?

I will remove the tabs you are describing from the carb adjustments tomorrow.

Thanks for all the advice.

Just get the dual port cover it's all you need(not the whole muffler). Should be around 50 bucks. Also, the max bar you can run on your 48 is probably a 42" bar. The 660 should pull that just fine. Let it eat the wood it wants though. Yes, pull the limiter caps I would not mill with those in there. Then again, at your elevation you might be ok. Don't scrimp on oil either. Stihl, Husky, Klotz, Maxima 427, etc. 40:1 with premium gas.

 

[JELIII]

I bought the whole mill set up with a double ended bar with a roller in the helper handle - I think the bar is 48", with an oiler at the other end. I am just starting to put it together. I hope this wasn't a bad choice of bars.

 

[Andrew96]

Well this is up my alley. I too have a quite new MS660...stock right now. So you guys would agree the hot setup is:
40:1 (not 50:1) Premium gas, premium oil, I don't intend on starting another oil ratio argument.
Muffler mod, either dual port cover, or DIY fabrication.
Of course, Pull the caps and run it a bit rich. 11,000rpm max.
Aux oiler for bars 36" or longer.
Let the saw eat the wood by not forcing it to cut.

So...anything else? I was hesitant to get a dual port cover as I didn't want it to be too loud. Therefore I haven't pulled the caps as I'm rich enough within the limiter caps range.
From the parts list I can see a high compression base gasket (thinner for higher elevations). Is this how you guys got a 'high compression' engine?
My big concern with any mods was reducing the lifespan on the saw. Hence..no muffler mod. Is this the correct assumption?

 

[BobL]

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From the parts list I can see a high compression base gasket (thinner for higher elevations). Is this how you guys got a 'high compression' engine?
My big concern with any mods was reducing the lifespan on the saw. Hence..no muffler mod. Is this the correct assumption?

from someone who seems to know his stuff.

There are gains that can be had by porting a saw for milling, However the standard approach of just increasing the port durrations and bumping compression might not be the best though.

A milling saw needs torque more than it needs RPM, ported for more torque and the saw will hold more RPM in a heavy cut and cut faster. If compression is increased much over stock heat will be a problem on a CSM.

 

[mtngun]

The dual port is controversial. I vote "NO." It's very NOISY, overpriced, did not increase power compared to a modified single port, and worst of all, blows hot exhaust on my hands to the point that it's difficult to hold the mill, even with gloves on.

I don't have a single port muffler to show you, but it is easily modified to give satisfactory results. The factory outlet hole is about 1/2", use a dremel or die grinder to open it up to at least 3/4". Watch that the enlarged opening does not bypass the spark screen.

There is a cage inside the muffler that has a few holes in it. The cage is restrictive compared to older 066 mufflers, so drill a few more holes in the cage, or enlarge the existing holes.

Before you can jump to any conclusions about compression, measure the compression you have now. If it is 160 or better, then you are good. If it is below 140, then measure the squish, and depending on what you find, you might consider pulling the factory base gasket and reinstalling the cylinder to have 0.020" squish.

Engines produce heat, fact of life. The whole operating principle is based on heating air. The hotter the air gets, and the more air moves through the engine, the more power is produced. Contrary to the what some might say, ANYTHING you do to increase power on a correctly tuned engine will increase combustion heat. However, by tuning the carb rich, the engine will be cooled by the incoming fuel/air mixture, plus it'll get more oil, too.

 

[gemniii]

I bought the whole mill set up with a double ended bar with a roller in the helper handle - I think the bar is 48", with an oiler at the other end. I am just starting to put it together. I hope this wasn't a bad choice of bars.

Now you need a dedicated helper.
That's a good setup if you've got big wood to cut.

 

[JELIII]

I just measured the bar it is approx. 55" from the center of the roller to the saw when mounted. This gives me about 44" of cutting width. Is this too much for the 660?

Before you can jump to any conclusions about compression, measure the compression you have now. If it is 160 or better, then you are good. If it is below 140, then measure the squish, and depending on what you find, you might consider pulling the factory base gasket and reinstalling the cylinder to have 0.020" squish.

OK, you lost me a bit here. Why am I checking the compression? I have never done this, but I can get a gage if necessary and give it a try.

How difficult is it to remove the limit caps on the carb screws? If I can only go 3/4 of a turn on the high, I guess I will need to take it off to get to where I am a bit rich. I am starting to assume that I will need a tach to get it set with any degree of accuracy.

I have some big wood and a couple of big friends, now I just need to get them excited about milling.

 

[woodsrunner]

I just measured the bar it is approx. 55" from the center of the roller to the saw when mounted. This gives me about 44" of cutting width. Is this too much for the 660?

OK, you lost me a bit here. Why am I checking the compression? I have never done this, but I can get a gage if necessary and give it a try.

I have some big wood and a couple of big friends, now I just need to get them excited about milling.

44inches of cut is a big bite. BUT, I would go ahead and try it. The way I see this you've already laid out the cash for the bar, chain?, the mill, the helper handle and saw. Go to it! :greenchainsaw: What will it hurt? If it is too much for the 660 you will learn that and then figure out what to do next.

If you have a pretty new saw and it runs good. I wouldn't worry about the compression unless you have some reason to think compression on the engine is low.

Big wood and big friends is the perfect combination for a chainsaw milling fiend.
Set that rig up get your guide rail system on and cut some wood. Don't overthink it too much. Remember this is fun. You will have a learning curve and rest assured you will stub your toe a time or 2, but so what? Have fun and holler at the rest of us when you run into something you can't figure out.



Scott

 

[Andrew96]

JELIII. The compression comment to you was because (without thinking about it), I hijacked your thread and got mixed in there. I'm sorry for that one. I'd really like to see your big long setup going in a photo. Remember your camera.

 

[Andrew96]

Engines produce heat, fact of life. The whole operating principle is based on heating air. The hotter the air gets, and the more air moves through the engine, the more power is produced. Contrary to the what some might say, ANYTHING you do to increase power on a correctly tuned engine will increase combustion heat. However, by tuning the carb rich, the engine will be cooled by the incoming fuel/air mixture, plus it'll get more oil, too.

MtnGun, Thanks for your comments on the loudness, and directed heat of a dual port. I had not heard about that before. I agree about the power/heat relationship. I think I might have a go at opening up my existing exhaust (I've looked at it all, and understand your comments) while retaining the spark arrestor. My milling has been done in cooler temps so that might help my saw. I won't bother playing trees until it's 10c or lower. I'll see what compression I get before I measure squish. I'll assume 160psi is about it in stock form.

 

[JELIII]

OK so what is squish? Does it matter where I drill the extra holes in the inner cage of the muffler. I have not taken the muffler off yet, but it appears as if the inner cage can not be removed from the muffler itself.

I bought the long bar because I have a couple of big walnut crotches to saw. I realize it would be more practical to get a shorter bar for most of my cutting. How long can I go without mounting the auxilary oiler. Any suggestions on where to get the bar and what kind? I assume this has been discussed in other threads, so I will look around.

Since it is snowing like mad here I hope to get the saw ready and the mill mounted today and give it a go tomorrow.

 

[BobL]

OK so what is squish? Does it matter where I drill the extra holes in the inner cage of the muffler. I have not taken the muffler off yet, but it appears as if the inner cage can not be removed from the muffler itself.

Lay the saw over onto the clutch cover like you are about to mill. Stand in the milling position and look at the muffler. Avoid drilling any holes in those areas you can see on the muffler otherwise you will end up with exhaust in your face or on your arms. Ever regular mufflers are problematic on a modern saw since the exhaust bounces off the log and onto the operator.

It's better for the operator if any exhaust mod can direct the exhaust away from the log and the operator. I describe this in this post.

I bought the long bar because I have a couple of big walnut crotches to saw. I realize it would be more practical to get a shorter bar for most of my cutting. How long can I go without mounting the auxilary oiler.

I run my aux oilers on all my bars (16 to 60") but these are used to cut Aussie hardwoods. Others can give you advice about your local softwoods .

 

[JELIII]

I have read a number of other threads and posts here that recommend enlarging the existing hole, but this will be a real bi#%@ working under that small cowling on the stock muffler. Any suggestions? I am considering cutting it off and welding it back on after I enlarge the hole. There are two holes in the muffler, the round one and then a small slot in front of it. I plan to leave the slot as is and just enlarge the hole to 3/4.

I took the rubber seal away from the outside of the carb adjusters and see the limiters. How do I get them out and do they need to go back?

I am more of a carpenter than a mechanic!

 

[splitpost]

I run my aux oilers on all my bars (16 to 16") but these are used to cut Aussie hardwoods. Others can give you advice about your local softwoods .[/QUOTE]

:jawdrop:bobl is that a typo,hope ur not starting to slip,LOL LOL