MS660, sleeper, or dud?

Just putting this out there so you can compare. New 395xp with 24" b+c $980 at husky dealer local.
 
I am thinking of sending my new 660 out to get a pop up piston and a woods port. Tell me I am not crazy to do this to an $1100 saw that runs fine now. I dont want to have any problems with the saw that is all ready running good but I do want some more power.
 
You are not crazy, I have one and she has been screaming for me for years now!
 
Most likely just replacing that choked down muffler by either reworking the existing one or replacing with a factory duel port would improve the dickens out of that saw .

I've said before that Toms 660 does okay but it's only a mere shadow of the 066 that was stolen .
 
A lot of times I find myself using the 460 instead of the 660 and it's sluggishness. I would love to get the 660 opened up a bit.
 
Just "runs fine" is a different saw from a good woods mod, which is running fine with more power and speed. Like Squish said, you can't go wrong with that model and better tuning. I think it's pretty established that a good job for a working saw doesn't shorten the life at all, maybe prolongs it. You might want to specify being on the conservative side, for a saw that you want to rely upon for a long time. You will probably like using it a lot more. Six or seven hundred more rpms with added torque is pretty noticeable.

Harder starting sometimes gets mentioned after modding, but that or any other problems shouldn't be the case with a good job by an experienced person. For a saw that you use a lot, modding is well worth it, imo. By the end of the day the work speed gains can add up too.
 
Most of the problem of the reason the newer models don't preform as well came be traced right to the exhaust system .

It's kind of hard to explain to someone unless they have a knowledge of two cycle engines .In a nut shell though it can't get in if it can't get out .Horse power takes fuel .You can't get same unless the exhaust can be evacuated in such a way that the transfer cycle of the engine can stuff the cylinder full of clean fuel/air without the residue of the past power cycle being present .Simple but sometimes complicated .
 
Thanks for making me feel better about this. I am sending the saw out early next week for a complete woods porting and a pop-up piston for $225. If you guys are correct on how much better it will be to run the saw I am sure it will be $225 well spent. Thanks for all the info guys.
 
If the pop-up work constitutes much of the cost, I might consider leaving that part off of the job. That saw will be strong as a bull with the stock piston configuration.
 
"Worth it" is one of those terms that can be defined completely differently for different people. From what I hear...which btw is the extent of my experience with pop-up piston mods...gains are seldom significant enough to justify the cost. Some were saying that once commited to that course of action, you are truly commited...no simple piston replacement in the future should that be needed.

But if you want to be able to say your saw is modified with blabla blabla bla down at the tavern with your chainsaw buddies, and $50 additional bucks for the privilege isn't a stretch for you, then I guess why not?
 
No pop up in this 066. Just stock piston and good ole school basic woods porting by WV guy.

Testing in square wood for accuracy in a chain test.

<iframe width="480" height="360" src="http://www.youtube.com/embed/mUTMEcvTLr0" frameborder="0" allowfullscreen></iframe>

Same saw chain testing in 23"

<iframe width="480" height="360" src="http://www.youtube.com/embed/21GX7mLg_gA" frameborder="0" allowfullscreen></iframe>
 
Thanks for the link. I think I am gonna save my money and not get the pop-up piston. Doesn't seem to really to increase performance that much to justify the cost.
 
I might add that the 066 pictured was a very fast powerfull saw .One of the strongest 066's I ever had the pleasure of operating.

Now on the pop up .The main reason I've done them is partly for experimentation but keeping in mind I have the machine tools and know how to do it .All it cost's me is my time which is a hobby any way and there's no way to put a price on it .

I might have mentioned some place that the next saw soup up I do which will most likely be another 038 Mag I'm going to leave the piston a flat top .I'll work on the windows etc but leave the piston top alone .With the exception of polishing the top but that's another story in itself .
 
Either way it's gonna make a big difference I don't believe mine is a pop-up. I'll grab my modded 460 over my modded 660 anyday of the week unless the wood gets over say 28" or so. My TW460 is the nicest saw I've ever owned, it's truly a thing of beauty to bury that sucker into a nice log. Everytime it makes me smile.
 
Skwishey, he sure does nice work, eh!

I feel the same way about my saws, two in particular. The old worn out 372 I sent to Scott was another one. That sucker was insane!

These days I get the same rush driving the Bullitt and pressing the go pedal until the boost gauge hits 8. :evil:
 
I guess the guy that offered to do the job knows the saw and appropriateness of a pop up piston for it, but there are variables. What is the squish when stock (area above piston and top of combustion chamber) would he need to mill the base of the cylinder to lower it to make a pop up productive, and by how much, then there is the allowable area above the rings to remove the outer area that creates a pop up piston, the shape of the combustion chamber....? Just starting off by saying I'm getting a pop up piston, unless it gets discussed with the person doing the work who knows the saw, there may be different levels of practicality. Cutting down the cylinder makes for a different degree of porting, one thing affects another. It might also be that two saws within the same model have different clearance when stock (some are dogs others are better). I'd be curious to know if the person doing it will be completely removing the base gasket and going with a sealant to raise compression, or making a thinner paper gasket, or? A few different ways to go on a mod depending on what is happening when stock and what you are after. Just following the basic formula for a woods mod, without a pop up, should really boost the saw.
 
A retired west coast logger/bikesaw builder that Al is quite cozy with ;), gave me his formula for a "stout" woods port on a 066 sans pop-up. I can tell you this....... IMO the pop up was not needed ! You won't be disappointed with a good woods port. Make sure you run it plenty before it gets shipped so that when you get it back you go...........OH MY, now thats what I like !!!

Steve
 
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Some of you guys may not hit the other site so I thought I would get the info over here.


A while back(a long while actually) I started making plans to mod my MS660. I decided I was going to do it in stages, and try different approaches along the way. The saw had the 0603 Magnum muffler installed before it ever saw wood. Knowing that port work was in the future, and wanting to keep the original cylinder stock to have a backup, I started searching for MS660/066 top ends. I found a set of two cylinders on eBay that had stripped spark plug threads. I took a chance and bought the parts. It turned out great. The bores were in excellent condition and there was no damage. I really liked the deal because one cylinder was a Stihl and the other a Mahle. I had $28.00 in two basically new cylinders. I bought a plug thread repair kit from NAPA for $30.00 IIRC, and I fixed the Stihl cylinder plug threads.


<a href="http://www.flickr.com/photos/41385771@N03/5161655062/" title="insert by zweitakt250, on Flickr"><img src="http://farm2.static.flickr.com/1190/5161655062_45baef7094_b.jpg" width="820"height="655" alt="insert" /></a>



The saw was assembled with the Stihl cylinder and the squish measured. The squish varied across four corners between .021-.025".



The workstand helps.


<a href="http://www.flickr.com/photos/41385771@N03/5161057611/" title="chassis by zweitakt250, on Flickr"><img src="http://farm2.static.flickr.com/1206/5161057611_1c45f56374_b.jpg" width="820"height="544" alt="chassis" /></a>


The first thing I did was clean up the piston. I removed all of the casting flash and then opened the windows for better flow.

<a href="http://www.flickr.com/photos/41385771@N03/5161055573/" title="piston window right by zweitakt250, on Flickr"><img src="http://farm5.static.flickr.com/4062/5161055573_492178040f_b.jpg" width="820"height="655" alt="piston window right" /></a>


<a href="http://www.flickr.com/photos/41385771@N03/5161055065/" title="piston window left by zweitakt250, on Flickr"><img src="http://farm2.static.flickr.com/1315/5161055065_7779fe4a5a_b.jpg" width="820"height="655" alt="piston window left" /></a>




I then started on the cylinder, cleaning up all the ports. I widened the ports to the skirt limits, but I did not change any timing, save for the intake duration which lengthens when you remove the silly lip in the floor. The upper transfers were widened toward the intake side and the port roof cleaned up. The lower transfers were lengthened, along with the cleanup. I prefer not to cut the lowers all the way to the base. The exhaust was widened at the bore, made more square, and the exit size increased.


<a href="http://www.flickr.com/photos/41385771@N03/5161657660/" title="intake 1 by zweitakt250, on Flickr"><img src="http://farm2.static.flickr.com/1405/5161657660_287bcd7a84_b.jpg" width="820"height="655" alt="intake 1" /></a>


<a href="http://www.flickr.com/photos/41385771@N03/5161053235/" title="intake 2 by zweitakt250, on Flickr"><img src="http://farm5.static.flickr.com/4002/5161053235_1bcb48bbca_b.jpg" width="820"height="655" alt="intake 2" /></a>



<a href="http://www.flickr.com/photos/41385771@N03/5161053675/" title="left upper 1 by zweitakt250, on Flickr"><img src="http://farm5.static.flickr.com/4066/5161053675_24bb9d08c0_b.jpg" width="820"height="655" alt="left upper 1" /></a>


<a href="http://www.flickr.com/photos/41385771@N03/5161657316/" title="exhaust 1 by zweitakt250, on Flickr"><img src="http://farm2.static.flickr.com/1384/5161657316_09bbb2caff_b.jpg" width="820"height="655" alt="exhaust 1" /></a>


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The muffler was also further changed by removing the internal baffle box. The muffler is now virtually identical to the ones fitted to early '90s 066s.

<a href="http://www.flickr.com/photos/41385771@N03/5161051549/" title="muffler 1 by zweitakt250, on

Flickr"><img src="http://farm5.static.flickr.com/4085/5161051549_fdcbd9ab08_b.jpg" width="820"height="655" alt="muffler 1" /></a>




<a href="http://www.flickr.com/photos/41385771@N03/5161653538/" title="muffler 2 by zweitakt250, on

Flickr"><img src="http://farm5.static.flickr.com/4131/5161653538_b941bf717d_b.jpg" width="820"height="544" alt="muffler 2" /></a>




After this set of mods the saw was run at the AS WV GTG at wvlogger's place. The saw ran fairly strong on its first tank of fuel, held decent revs in the cut, and pulled the 8 pin OK with the 25" bar buried. When I arrived home I checked the compression. It topped out at 167 psi.


The next step was to square the cylinder. I turned a mandrel from 2.375OD-1.5ID DOM tubing. The OD was set to 2.125" which allowed a tight slip fit of the cylinder. The face of the mandrel was cut at a 7° angle, .75° steeper than the 7.75° stock squish angle that I measured as best I could. This would allow me to true the squish band and set a precise squish. I mounted the cylinder on the mandrel, then machined a center in the top of the head. Once that was done I faced .010" from the base of the cylinder. This made sure that the bore and base were perendicular to each other, though the stock runout was no more than .001". Sorry for the blurry video, dirty iPhone lens.


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After that was done, The work was removed from the lathe and a piece of self-adhesive sandpaper applied to the face of the mandrel. A measurement was made from base to squish band, then the mandrel inserted in the bore. Rotating the mandrel by hand allowed the squish band to be trued, and a precision squish to be set.

Unfortunately during this process I scratched the intake side of the liner with a diagonal score. I should have cleaned the swarf out more often. The fact that I have less than $40.00 in the cylinder makes it hurt a little less. I am not sure how much this has hurt the top end, but the saw is now making over 170 psi of compression. Next, I reassembled the saw and checked the squish again. This time I measured .019" at all four corners. This is the result I was looking for. Now the base, bore, crown, and squish band are all square and true.




<a href="http://www.flickr.com/photos/41385771@N03/5161048015/" title="mandrel 2 by zweitakt250, on

Flickr"><img src="http://farm2.static.flickr.com/1047/5161048015_7891a4df7f_b.jpg" width="819"height="1024" alt="mandrel 2" /></a>




<a href="http://www.flickr.com/photos/41385771@N03/5161652336/" title="mandrel 1 by zweitakt250, on

Flickr"><img src="http://farm5.static.flickr.com/4086/5161652336_f600e51785_b.jpg" width="680"height="1024" alt="mandrel 1" /></a>




<a href="http://www.flickr.com/photos/41385771@N03/5161656020/" title="squish 1 by zweitakt250, on

Flickr"><img src="http://farm2.static.flickr.com/1095/5161656020_421ee6e112_b.jpg" width="820"height="544" alt="squish 1" /></a>






For me it is running ok, but I know I have left plenty on the workbench. Not sure what I will do next, but I'm sure something will pop up.

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Thanks for looking.


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Looks good .The only comment I can make is the mention of the scratch in the cylinder which most likely won't hurt a thing .

Prevention of same is one of the reasons I chose to use mandrels of nylon 66 instead of steel .I've seen them made of aluminum also .

That comment aside it looks as though the work made improvements as intended .:)
 
I'm in the market, or maybe just the mood, for a new saw. I've got to replace the 394, as I don't have any other running saws, well I do have the Husky 66, but it's a tad small. I know the 660 isn't the same as the old 066, but I was wondering if a dual port muffler and a retune would make up for it, or should I just get an MS460 and be done with it.
I have a strong running dual outlet 066 Magnum-28" in my stable that sit's between my 395XP -32" and 372XP -22".
I hardly ever use it ,only if I severly rock out my 395's chain and need a quick backup.

I'm seriously thinking of replacing the 066 with a brand new Husky 390XP- 28" with a muffler mod.
The 390 with 88cc, 6.5 h.p. and 15.6 lbs versus the 660 with 92 cc, 7 h.p. [sounds overated to me, even still the muffler modded 390XP should bring it close] and at 16.5 lbs , a lb heavier then the 390XP along with more bulk, vibration and no air injection.
After running my 372 and 395 the 066 seems dated big time. And from some of the new MS660's I have run they're real dogs in power.
I hear the 390XP is even more smoother in vibes then the 395.
 
Just got my woods ported 660 back today. Wow! What a difference over stock. Now I am thinking of sending my 346xp and my 441 to get done haha.
 
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