Stihl 661 vs Big Bore 064

Here we are watching the same 661 as seen in the previous 661/066 build sequence videos running against my newly upgraded 064.
I used a standard oem 660 cylinder assembly for this project.
Upon review of the dialog, I noticed a qualification was needed regarding the commentary about the differences in the combustion chamber work. The 661 chamber was reshaped along with the flow tricks added in. I did do the flow tricks to the 660 cylinder for the 064. I did not reshape the combustion chamber however.
As mentioned, there is a 1.2 pound difference in weight between these two when fully fueled.
Timed runs as follows:
661 @ 13,080 rpms 12.78 & 11.00
BB 064 @ 13,080 rpms 13.70 (cut out) 13.76 & 12.17
The 661 have some more work done and runs a little faster. The 064 runs a little slower but weighs quite a bit less.
I well pleased with the outcome of the 064 in BB trim.
I am currently available for custom saw modifications. please shoot me an email if you are interested.
[e-mail]
Thanks for watching.

[@TonaldDrump686]

That is some sharp chain.

[@outinthewood3578]

That 661 is quite the runner ! Check your mail it has good news !!

[@hotsaws101]

Thanks, and for stopping by. Be home in a few weeks. Looks like I'll be needing to do my part. Thanks for watching and blessings on this, His day.

[@woos31]

1 pound of saw makes a HUGE difference in a man's decision making process when full fatigue has set in.............. ... your vision narrows along with awareness, you get lazy and don't get as far out in the clear as you should, so then you start short cutting all of your processes. That is the trifecta of a timber cutter to get his logger's reward and not going home........ On a positive note, thank you Mrs. Jack again for assisting in "big kid time" lol! Where would we be if not for your help in this 1 ton hotrod saw update as well as making my bill fold quiver as I begin my firewood cutting, making thoughts of hot rod saws rampant in my mind.

[@hotsaws101]

Woos hi. Seems like on Thrusday it's the "worstest". Yessireee, cuts a little slower but comes in around 1.2 pounds less. Trade-offs. Always considering the trade-offs in the saw world. I'll pass along the gratitude. Thanks for watching.

[@maninaboysbody]

What do you think of the MS500i ??

[@hotsaws101]

I have not had one in my meat hooks just yet to have an educated opinion. The little I do know is that they seem to be engineered into submission based on all the cut aways & diagrams I've seen - wiring, lines, return lines, motherboard, etc., etc. My buddy Dave over in Ireland is supposed to be getting his meathooks on one soon. You might check out his channel for a professional timber fallers opinion - outinthewood - is where to find him. Hope "Betty" is fairing well!

[@maninaboysbody]

@@hotsaws101 Bettys semi-retired dieting on pine lol I gots a 064 that i got from rich in oregon "TheChainSaw Guy The Chain Saw Guy" a while ago, fine saws!! mom got sick so i gotta wait on that 288 project , god bless.

[@andrewotero1972]

Got a few 64 's on the bench are you using a OEM cylinder or a am cylinder? I've used cross performance big bores on my 64's in the past they worked up pretty decent with a little bit of decking. Great videos I'm always looking at ways to get a little bit more performance out of the saws haven't dealt with the 661 hard to get away from those 066 660 and 64,s 😀

[@hotsaws101]

anfrewotero hi. Thanks. Every Cross cylinder assembly I've looked at and/or tried was junk. Thin plating, inadequately plated, out of round plating (probably the cylinder itself there). I am not a fan of any of the am choices except Meteor. I cannot believe anyone can properly build one of those cylinders and have it live. I hucked the 084 version I was going to use myself. It was after a thorough visual inspection. I did not even have to use my bore gauge to tell. I use oem parts 99.9% of the time. Thanks for watching.

[@prescribedfire1953]

Jack how do you decide on what the unloaded WOT should be? I don’t have a tac so I tune by ear.

[@hotsaws101]

prescribedfire1953 hi. I never owned a tach until a few years ago. The only saw I "blew up" was the 346 on record in a video. I tune my work saws by ear while felling with them. I take my time - an entire day at the very least to get one dialed in. In the end, they should have a slight burble at high idle & the screens showing a medium tan color. Thanks for watching.

[@prescribedfire1953]

Thank you. That’s what I do too but I seized my first saw (an old 075) a couple months ago. I don’t know what went wrong.

[@hotsaws101]

There is a lean seize which usually nukes the intake side of the skirt. Improper jetting, a bad seal, hole in a line, etc. Since it is an 075, which has not been made for years, I wonder if your issue was a bad seal. There is the over revving seize which melts down the exhaust side. Dull chain and grinding away gets you that. It is pretty commonplace actually.

[@richherman4257]

I have a 064 that needs to be rebuilt and I don’t have the time to do it myself I wanted to see about you porting it too after it’s running if your not too busy

[@hotsaws101]

Rich hi. My email address is in the description area of most of the videos over the last few years. That is the best, first point of contact for me. Thanks for watching and blessings on this, His day.

[@michaelremski8295]

So how did the 2 saws feel in the hand? Listening to them in the cut sounded very similar, did they feel the same? Not meaning "how fast" but did either feel like it bogged down if you pushed too hard? Thank you again.

[@hotsaws101]

Michael hi. The 661 is more smooth from the spring mounting system. With the quad loop delivery system in the transfers it has good lowend even with the more over-square engine design. You can definitely tell the 064 is an old skool rubber mount design. The BB 064 seems like it has good power down low. And I did my best to enhance that trait. This was the first go-round with it so I didn't want to tighten down the high speed needle that far. Also, I think that when it was assembled originally the crank was not aligned perfectly and it suffers a little because from that part. I put some time in "kilting" trees with it so after I give the crank a once over, I'm hopefull it will come around a bit too. I probably could have pulled on either a little bit more but in an effort of fairness I try and be as consistent as possible in the saw-off. The 064 is around 1.2 pounds less weight and runs through the cut around a in second or so more time. Trade-offs. There are always trade-offs in the saw world. Thanks for watching.

[@michaelremski8295]

@@hotsaws101 Thank you very much for this info. I'm just a homeowner that keeps a saw around for storm cleanup and a little firewood (East Coast), but as an engineer I love hearing what the changes do. I'm old school muscle cars instead of new fangled turbocharged so a lot of your changes/explanations make sense. 1.2 lbs over 8 or 12 hours is a lot. I'm guessing a hybrid of the 064 with spring mounting is "can't do". Thanks for sharing all this and the "oil oil oil".

[@hotsaws101]

None of the 064/066/660 came with spring mounts. Where there is a will and a HOLE lot of cash there is a way. It would be a project for an engineering type guy....

[@hotsaws101]

As I was thinking further, I run chains that will feed themselves. So they are kind of aggressive. This means it doesn't take that much to stop them. But at the same time I can pull up pretty hard while under bucking to the point of moving the log sometimes.

[@michaelremski8295]

@@hotsaws101 That makes a lot sense. Also sounds like "millions of board feet" of experience to get to that knowledge, thanks for sharing it with us.

[@98fishingfool]

You wouldn’t happen to have a dual key flywheel for the 064 ?

[@hotsaws101]

Brett hi. Nope, sure don't. Thanks for watching.

[@johnclarke6647]

What kind of tachnare you using andbwhere did you get it?

[@hotsaws101]

John.hi. Pulse pet-2100dxr. Same brand as what Husky uses. I ordered it. Think they have a website. Might want to do a search. Thanks for watching.

[@topchoppers7980]

Hey hotsaws101 I'm looking for a better saw any chance you would be willing to build a saw either from stock set up or even a ground up build please let me know great vids, and God bless

[@hotsaws101]

Brett hi. My email address is in the description area of most of the videos over the past few years. That is the best, first point of contact for me. Thanks for watching and blessings on this, His day.

[@farmerjackson709]

Where did you get your tachometer from?

[@hotsaws101]

farmer jackson hi. I ordered it. You might try a search. PET2100dxr if memory serves. Thanks for watching.

[@kylemueller8906]

With all your time on a 064, have you ever had a crank break or have seen one that has.

[@hotsaws101]

Kyle hi. No not personally. Thanks for watching. The early, heavy metal flywheel 066s era was different story. Thanks for watching.

[@robertshoemaker6204]

Ran many a 064s back in the day replacing our 056 mag II....was lighter but had a glass bottom end kept breaking them, then the 066...much better design bottom ends much improved...same with 084/088 same thing.....Shoe

[@elonmust7470]

The 064 used the same bearings & crank as the 066. All this about 064s having weak bottom ends seems like a bunch of folks were expecting their 064s to hold up like an 090g.....

[@ericwyke155]

Hi Hotsaw101 in this video you made a comment oil oil oil and the fuel ratio for saws that has mTronic which is stoichiometric ratio do you still run Motul @ 50:1? Because the stratified engines run stoichiometric ratio’s do you think that it would be better to run a lower percentage of oil right around 44 : 1What is your comment thank you very much

[@TonaldDrump686]

I split the difference and run 45:1. Idk if maker much difference in speed or longevity, but it puts my mind at ease.

[@hotsaws101]

Eric hi. So we may be talking a little bit about apples and oranges here. The stoichiometic ratio does apply to the process in a theoretical aspect - where there are just enough air molecules to react completely with ALL the fuel molecules so that the burn is complete and absolute. In automotive applications it seems like the number is 14.7:1 air to fuel. But, it think that there are variables that effect the actual number based on the design, flow characteristics, efficiency, etc. of the engine in question. I'm not sure if the 14.7:1 ratio is completely accurate in all chainsaws. The entire premise is an engine that produces less/no emissions. My understanding is that a lean condition burns cooler but it takes much more energy to lite if off and that is where the excessive amount of heat comes from, and the possible meltdown. In a real world application, 14.7:1 does not produce maximum output power. That ratio is also variable depending upon some of what I mentioned above. For years and years the magic hp number was ~ 12.5/13:1, again depending on some engine criteria. Now with some of the modern design & engineering advancements the ratio has a range from ~ 12.8:1 to 13.2:1 for maximum horse power applications it seems. With all that, the new smog saws run sloppy tolerances to compensate for the higher temps while running because in an effort to clean up the burn process of excess hydrocarbons they run lean comparatively to the older designs which in turn means they run hot. The "oil oil oil" statement comes from this perspective in an effort to offset/negate those two non ideal factors with the "new kids". The smog saws need a dense oil with a high/er viscosity - which generally lends itself to having great film strength. I recently tried a 40:1 fuel/mix oil ratio in a felling application. I did not like the performance aspect with my saws and went back to the 48/50:1 i used since in the early '80s. I blend my mix oil and have been for the last year, year and some months. Either of the 800 2T Motul oils are engineered for maximum abuse to an oil. I never noticed where running a more concentrated ratio in either the off highway or roadrace Motul choice benefited the process. But, and there is always one of those, we are talking about my saws, chains set up as appropriately as I can get, and how I've tuned the jetting accordingly. Thanks for watching.

[@voxpopuli905]

I have an 064 and I think it possibly runs even better than that one

[@joshmoulson9372]

Afternoon Hotsaws101, regarding the noticeable difference in weight... Is it just me or are the modern saws getting heavier than the 'old skool' saws? For example, the 036 and the Ms361 are lighter than the modern counter part the Ms362 with noticeably less longevity and power. I'll put it out there and say the new saws go faster, but do less and you can't beat old skool cool. Love the work you do with saws, thanks for the showdown.

[@arborist460]

Weedeaters are the same way...my 131 is way heavier than my 130 but now it's a runner...I wish my old 130 was new to be a better comparison...

[@arborist460]

The weight comes from all the emissions junk they keep addin to make 2 cycle engines try n run/burn cleaner...gobs em off if you ask me

[@tommalone4310]

josh moulson my new MS362CM powerhead is only 12.3 lbs and 4.7hp. So, they are not heavier and they are stronger. Not sure on the longevity yet, but I have an 1986 model 028 that is still running strong. So I do agree the old ones lasted a long time!

[@joshmoulson9372]

I think it's just me missing my Ms361, but I agree the 362CM rips in wood. Trim the squish and it's quite the ride... No word of a lie we have a 026 in the truck that has never had and seals changed, no new rings, no new lines and it's still going.

[@hotsaws101]

Gentlemen, since in the '70s and early '80s manufacturers have been utilizing a lot of avenues to lighten up their saws. Lightweight materials, reducing the replacement machine size, and some "prudy" trickiness in thought and design. 480 to 181. 056 to 064. The early 066 was heavier than the 064s but it displaced more cc and had more power also. So it, like with all things saws, depends on which particular two machines we are discussing. The 462 is light years ahead in the lightweight arena. The 572 is an inch longer and at least a half pound more than it's predecessor. But, it is way smooth and has more power. Summing it up, generally yes, saws for the most part have been getting less in weight. Thanks for watching.