Anyone using an Echo 670

[glens]

For what you're saying you'll use it for, you probably wouldn't even really notice a difference between the 62 and the 56.  The smaller saw is 90 bucks less right now at the web site and you could pick up your saw from the dealer immediately instead of having to wait.

.325 chain will be fine.  In fact, it will probably cut a little smoother and faster for you than 3/8.  I don't know what chain brand/model they're using, but the .325 might cut a slightly narrower kerf as well, which would only increase the speed margin.

Whether a saw has open or closed ports doesn't need to be a factor in the decision to buy a firewood saw.  To see the difference, sort of, look at the images on http://chainsaws4u.com/husqvarnachainsaws.htm but beware of that page, there's a lot of hype in the comparisons that aren't really comparisons, or if they are they're about things that really don't matter.  The closed port system has distinct openings at both the top and bottom of the external-to-the-cylinder transfer passageways.  The open transfer has passageways which utilize the sides of the piston as their inner "walls".  Both systems work well.  In fact, the open transfer setup might do a little better job of getting lubricant to the crank bearings.

A 16 or 18 inch bar ought to suit your purposes well.

Enjoy and be safe.

Glen

 

[TonyM]

You know what sucks? Less than a week ago someone sold a brand new Deere CS-62 for $300 buy it now on ebay. I just missed it! That would of been a good deal for you, Bob.

 

[jokers]

Hi glens, I`m not posting to pick on you although it probably often seems that way, but what exactly does the tranfer style have to do with getting lube to the crank? The fuel/oil mix is drawn directly into the crankcase, hence lubing and cooling the bearings, and then is forced up through the tranfsfers to the combustion chamber by the downstroke of the piston. Closed port engines GENERALLY make a little more horsepower than a similar open port engine. Probably insignificant for the purpose of this discussion. Russ

 

[dozerdan]

Efco 962

Bob
Dont be afraid to go with the Efco or there green twin models of saws,that were mentioned above.
I just received one of the older 962's in for porting work.
I did run the saw in some 14" red oak before I disassembled it.I was impressed to say the least.This is the fasted out of the box saw for its size that I have ever seen.Not by a little but by a lot.There is no comparing this saw to an 036 Stihl or a 362 Husky.
I will have to admit that the saw I have here is pre EPA.
The saw actually has the best port timing numbers from stock that I have ever seen,better then the 066 Stihl.
Where are you located at in Pa.
You are more then welcome to come here and run this saw,if you want to.
Later
Dan

 

[bob gresko]

Dan thanks for the info. I live in S. Williamsport - Lycoming county. Thanks for the offer Bob

 

[dozerdan]

Bob
I am not that far away from you.I am in McClure 17841,about 15 mile East of Lewistown on the map.
Call me anytime.
Later
Dan

 

[glens]

Russ,

I never feel picked-on by you.  For my reasoning behind the statement about crank-lubing, please refer to the two images at the bottom of http://chainsaws4u.com/husqvarnachainsaws.htm (ready reference).  It might be necessary to save those images to disk and manipulate them somewhat to see much detail.  Anyway, it appears that in the open-transfer example the charge need not take such a circuitous path, and that the path leads in part right by the outer bearings.  But perhaps if that's true it could spend a little less time at the wrist pin and underside of the piston, which areas might possibly benefit from all they can get.

We agree on the main point:  that for purposes of this discussion the two types are probably equal.

Glen

 

[bob gresko]

what does DIN horsepower mean compared to bhp?

 

[glens]

DIN horsepower is a metric representation of the English unit of measurement.  It's extremely close but does differ such that the DIN hp number is slightly higher (like 1½%).

I'd be remiss if I didn't point you to the fun results of a search on this forum for "din horsepower":  http://www.arboristsite.com/showthread.php?s=&threadid=7683&highlight=din+horsepower

Glen

 

[jokers]

Good glens, I`m glad you`re not feeling picked on. As far as the pics of the barrels showing the ports at the link you provided, unless I looked at different pictures than what you suggested, we are seeing two different types of engine construction, the more traditional cylinder that bolts to a crankcase from the Efco/John Deere and the integral cylinder/crankcase top half of the 029. Actually I`m glad you referenced that picture because it may be worthy of discussion for a different reason that I`ll get to. On the Stihl 029 jug you can clearly see how the transfers drop right down into the bottom of the case which as you noted would lead to a smoother flow up and through the transfers, on the Efco jug you don`t see the bottom of the transfers which would be more circuitous as the fuel flows from the bottom of the engine upwards. The fact that the Efco jug purportedly has closed transfers and the Stihl jug has open transfers is purely coincidental to this discussion. Depending on the make and model you may find transfers of either type that drop into the base and others that don`t. It is a definite plus to have those that do, in this case making the Stihl look atleast a little more sophisticated. For a better illustration check out the thread "Creative Advertising" by Dennis which has decent pictures of both types of transfers. At any rate, I`m pretty positive that the pressure created in the base of the engine by the piston`s downstroke does a good job of covering the bearings with fuel/oil. Russ

 

[glens]

Thanks for pointing me to that thread, Russ.  It just stole a good hour from my life.

One thing that I saw mentioned there which is valid-sounding is the concept of minimalistic free crankcase volume.  All things being equal, the 029 jug shown in the JD link above would have to be less desirable in that respect.

Another thing I saw touched-upon there was Walt's idea that chain can run too fast for it's own good.  He evidently gave an upper limit of 10k RPM, but the drive sprocket pitch diameter would have to be a factor (I digress).  I'd certainly hesitate to put a figure on it, but I know from working wood that it's entirely possible to overspeed a tool and burnish it.  If the time ever arrives when saws are running 15k RPM in the cut I'd think the threshold of diminishing returns would be close at hand if not passed.  I'd bet one could find where I've thinly hinted at that before, and I never knew Walt had said anything about it.  It really is a shame he's moved on.  As you'd probably guess, I likely wouldn't agree with everything he'd have to say, but I bet I'd enjoy reading it.

Those images at the JD site are of very bad quality, and the best I can determine is that the Efco jug does in fact have the transfer behind cylinder wall.  I knew that comparison was really invalid because of the differing construction models, but just didn't want to bring more than necessary to the table (I know, that's got to be hard to believe).  I don't find any value to speak of at that site, and in fact it makes me rather mad since it's almost totally apple to orange comparisons.

I feel like I had something else to say but I guess it weren't important 'cause I don't recollect it now.

Glen

 

[bwalker]

One down side I can see to a open transfer design is the amount of bearing surface the piston/rings ride on. Less surface results in increased ring wear in other applications so I think it would apply here also.

 

[jokers]

I vaguely remember Walt`s assertion that you could move a chain too fast in a cut and I understand what he is saying, but trying not to rub salt in a sore spot for Walt, I believe that Art, or Ken Dunn, or one of the Rupely`s spoke of an 090 turning about 17,000 with a 9 pin sprocket that was a wood eating machine. I`m sure that I`ve got the important numbers screwed up but the idea was that the surface feet/minute speed was much higher than what Walt believed. That being said, I sure do miss Walt`s posts, I believe that he is very knowledgable in many things chainsaw related and he is an entertaining character when he wants to be. He is definitely one of the old guard and it`s a shame to see all that experience wasted on trout fishing forums. Russ

 

[TonyM]

Bob,

If you end up with the CS-62 or 962, let us know what you think of it.

 

[TonyM]

I'm actually starting to LIKE the CS-670! I think I've got near 10 tanks of fuel through it now. I opened up the exhaust a little with some muffler modification, and with the limiters off the carb adjustment I've been able to narrow the gap with the 372XP. I'm going to do some more timed cuts tomorrow, but my guess is the CS-670 will be closer to 90% as fast than the 83% I had last time. The saw seems well constructed, has a nice air filtration system, and has a feature like Air Injection. It starts easy and runs good. It also has a better balance than the 372XP. Even though it weighs the same, I get less fatiqued running the CS-670, partly because it is less powerful, but mostly because the bar tips up when I lift from the front handle, where as the Husky bar drops slightly when I lift from the front handle (both with 20" bar). I think the better balance allows the operator to help lift with the rear handle, instead of having to push down on the rear handle to raise the bar nose, thereby requiring more lift at the front handle to hold the saw. If I had any complaint, it is that the gas and oil caps come off hard, but then again, that could be a good thing.

Unless one was concerned with having the ultimate power to weight ratio in a saw, I think the CS-670 is a good saw.

 

[bob gresko]

Tony, I ended up getting the echo 670. I haven't had time to run it much yet. Infact I haven't had time to get on this bullitian board to say why I chose it over the jd62. I bought the saw from a dealer who stocks both echo's & jd's. When I have more time I'll try to list my reasons for buying the 670. Tony, I'd be interested in the results of the tests you are doing on the 670 - please keep me posted.

Also, I've never bought a new saw (always used ones)before, and would appreciate any advice on breaking it in -- I don't want to hurt this baby. I've never used a 50:1 mix on two cycle equipment and am a little leary even though the dealer recommends it. Thanks everyone. Bob

 

[jokers]

Hi Bob, I`ll tell you what has always worked well for me. Run a couple of tanks of gas through the saw on hi idle with the bar and chain on. Obviously you want to place the saw in an out of the way place where noone could get hurt. Then take it out and run it wide open through several cuts. Stop and retension the chain and go to work. Don`t run the saw in the cut at partial throttle, don`t lug the engine, and keep it clean. I`ve never had a problem with undue wear from running 50:1 with a quality oil like Echo, Husky, Or Stihl, but have recently switched over to 40:1 in defference to the opinions of many well experienced saw men like Ken Dunn. Ken actually recomends 32:1 but I haven`t gotten there yet. Next I`m switching from Husky oil to Mobil MX2T synthetic. Oil that is superior to OEM oil and the price is right. Russ

 

[TonyM]

The Echo manual reads

"There are no special requirements for engine breakin. After normal operation and two (2) tanks of fuel, engine break in is complete."

I wouldn't worry about using 50:1 mix. Echo could never have a two year warranty if they weren't certain 50:1 was okay. I personally feel that 32:1 is better, but there has been a lot of debate on the subject.

As long as you follow what Echo recommends, you're covered.

 

[treeclimber165]

I've owned or been issued many Echo saws. At Davey I got a new 3400 every 9-12 months and my old one went to my groundman. I've never done anything special other than avoid long hard cuts for the first couple tanks of fuel. Just gassed it and went to work. Never had any break in issues, they always ran well for me with great compression.

 

[bwalker]

There are two issues that need to be resolved when breaking in a two cycle. They are- freeing pent up stress in the metal components of the saws motor and seating the piston ring to cylinder wall interface. The stress releiving part is accomplished by running the saw up to operating temps and then letting it cool completlly. After a few cycles of this you can move on to the next step of seating the rings. This is best accomplished by warming the saw up to operating temp and then making a full load, full throttle, bar burried cut followed by a cool down period. The full load period should be no more than 5 seconds in length followed by at least 30 seconds of light load. Repeating this procedure 15-20 times will result in perfect break in. After that run it like you normaly would and IMO use a 32:1 ratio of MX2T.