Got my Walker's Mufflers!!!

[glens]

Drew, I don't think the "picture" in the manual is <i>really</i> meant to be an actual indication of screw position.&nbsp; If you want the best results, work up a system combining the aspects you like from all the advice you've been given and information you've read.&nbsp; Then go through the cycle twice to ensure you're not too far out of kilter in any of the parameters.&nbsp; I rather doubt that you'll get very far away from where you need to be with the throttle-stop screw, and turning it to any position you would not otherwise be using for the sake of adjusting something else doesn't make much sense to me (unless maybe when trying to debug a malfunctioning system).&nbsp; All three screws interact and that's why you should work through them all whenever you're at it.

As for myself, and assuming you're not talking about using the saw competitively, I vote for using the ear to get a little blubber that just goes away while in the cut.&nbsp; If you're constantly tuning for maximum safe RPM with a tach you're standing too close to the edge.&nbsp; Especially with a $700 tool.

Don't forget that metering lever height and pop-off pressure are very important settings and your screws will not be able to do their thing if either is wrong.&nbsp; I find <a href="http://www.aerocorsair.com/id27_m.htm">http://www.aerocorsair.com/id27_m.htm</a> (and links within) to be quite valuable in a general information sense and you might too.&nbsp; Maybe some of your questions will find their own answers if you can see what all's going on.

Glen

 

[Stumper]

Good advice from Geofore. The throttle setting IS part of the tuning process BUT it is an external adjustment not an adjustment of fuel metering settings inside the carb. If the Hi and Lo jets are set right (and everything else in the carb is okay) the idle speed screw will do nothing to change that. ALL that it does is adjust the amount that the throttle plate is held open when the trigger is not depressed. If things aren't quite right (but halfway close) we can adjust the idle screw to keep the saw idleing while we fine tune the other adjustments. Once the saw will idle without loading up and dieing and accelerate without bogging and the hi side is set for maximum safe rpms(or max power in the cut) we've got it.
A few older saws (Echos) provided a knurled idle adjust screw so that the operator could tweak it any time he wished-the reason being that idle cold and idle warm tend to be at different speeds and a partially blocked air filter tends to richen the mixture making the saw tend to die at idle ect ect. The external adjustment didn't endure-wasn't really needed but the moral is -set the idle wherever it needs to be for the condition of the moment.

 

[Drew78]

Thanks guys-

Yeah the saw is running like a top, I shouldnt have messed with it until the saw warmed up and had some time to run fuel through it (since I had started them with fuel for the 1st time in 2 wks). So I was just trying to get back to where I started. Pretty sure the saw still 4-strokes at the top, but I will check it later.

-drew

 

[Drew78]

Stumper-

Thank you for your response. I have read it about 10 times now making sure I understand it completly. And I must say that I agree with you. That has been my thinking for a while now and I think it just clicked with me the way you wrote it.

Like I have said, at first I messed with the LA screw and actually had it turned way out to slow it down. Dumb mistake, should have let it warm up first then adjust. The L screw is set just about dead nuts between completly rich and completly lean and it responds well to accleration.
Just wanted to thank you for your post

-drew

 

[jokers]

Yeah Drew, I`ve been re-reading too and you are right. Throttle position has no effect on crankcase vacuum which would in turn work on the carb venturi, and I doubt that crankcase pressure pulses would have any effect on the metering diaphragm. What`s the metering diaphragm? I guess I don`t know either! Let`s look it up on the `net. You guys who are hooked on tachs are also right about the validity and value of one size fits all tuning based on rpm. The only thing regarding tachs I haven`t figured out yet, is why some of the most esteemed chainsaw performance experts here advocate running the engine several hundred rpm below what the factory says max rpm should be. How did these "supposed and self appointed" experts come up with these numbers that must be arbitrary? Now I am starting to doubt those whom I considered experts. Their success at performance tuning and saw building must be pure, dumb, luck.

This so profound change in my paradigm is making my head hurt. I`m out of here. But first Drew, I want to thank you for the enlightenment.

Russ

 

[Drew78]

Not sure if or HOW I enlightened you my good man, but nonetheless your welcome although I have to believe you still think using a tach is total crap. I am going to employ a dual method ear/tach. Again thanks to all who have helped, especially Jokers. Your enlightnement is my happeiness!

-Drew

 

[jokers]

Thank You Drew, and to borrow a phrase, "You complete me".

I don`t think tachs are total crap, I have two, just that tachs are tools that are no more capable of correctly tuning your saw without input from the operator, than a screw driver is.

Fine tuning your saw, which is what I presume you are trying to learn, is a multistep process. Tach, listen, timed cut, or listen, tach, timed cut. Oh, and put in a new plug to be read periodically while you`re finding the sweet spot. The order is flexible to an extent. I believe that the bottom line is that each saw has it`s own sweet spot and you need to learn to recognize it. If you had five 460 Mags, they wouldn`t all run at max potential at 13,500 rpm would they? They would all more than likely run average. Well, I`m being redundantly redundant. My head still hurts. Gotta go.

Russ

 

[Drew78]

Jokers thanks, your a real sweetie!!

My problem is that I get SO caught up in the details that it plagues me and I never believe that I have it right, eventhough I probably do. I guess I am just an idiot about things. Its my dads fault, ???? it! He's so anal retntive, and I am too.

So just relax right, everything is set up great, saw runs great, life's great...

Ok better now.

Well now my head hurts, time for a couple of beers when I leave this office in 10 min. !

-Drew

 

[bwalker]

Jokers is right in that a tach will not net you a perfectly tuned saw. It will gte you in the ballpark though, From there you can fine tune till you reach peak performance. To me the tachs most valuable function is that it will allow you to return to a set tuning point day after day once you find the best rpm. Try that with you ear.

 

[glens]

The "best" setting for a particular day, with it's particular atmospheric pressure and relative humidity and temperature and bar and chain will not be the best setting for any other day in which any of those parameters are changed.&nbsp; If a tach can accommodate those changes then I really need to get one.&nbsp; If I had one, I would only use it on occasion to ensure I had not exceeded the maximum rated RPM after setting the carb.

But then I don't race saws.

The throttle stop setting will affect the needle settings for idle if it's got the throttle plate open enough to get into the gray area where both the high and low jets are in service, but then there are undoubtedly other problems which need attention.

Glen

 

[bwalker]

The "best" setting for a particular day, with it's particular atmospheric pressure and relative humidity and temperature

Glens, In a basic sense you are adding fuel to control peak rpm on a saw. That said if you set the saw to a certain rpm daily it will have the same A/F. This is where a tach comes in really handy. BTW In a no load state a saw tuned properly will be way on the rich side. The reason for this is the fact that a two stroke makes best torque at richer A/F and peak power at a leaner ratio. That is where a power jet carb comes into play on a dirtbike.

 

[stihlfast]

Tach -vs- ear

Drew....Glad you like your new 460.....They are quite a saw !.....I have read quite a few replies to the tach method and must say that I heard some really good points of view....and some......Well........ questionable.....but none-the-less it sounds like you recieved some darn good info in my opinion......I even learned a thing or two......I guess a guy is never too old to learn ! I have found (as I am sure most everybody has) that the factory sets the new saws fairly rich...(but have leaned the new saws out a little more over the years) as the saws are getting lighter and have more power as the years go by I would assume......I really can't top any of the info you you have been given......I get mine ported when they are brand new and run the saw at (14.8) break-in period for about a week and then (16.8) from there.......so it is a whole differen't story then a stock saw......I use the ear and tach method.....my ear will tell me when my saw is running hard or as I put it.....(tugging on it's guts)......the tach just confirms it is all......( it is a little harder to get a ported saw to 4 stroke so it can be a little tricky by ear at times......(especially when ya have bad hearing) LOL....that is one of the only reasons I have a tach..........I read a reply to my post on the max-flow air filter and the person was right on the reply...without the "finger port" (that's what I call it) opened up..the max-flow wouldn't give your saw a heck of alot more air but rather cleaner air......the finger port is an important part of the hop-up proccess.....I guess I forget sometimes that not everybody has a need to run ported saws......but in any case the max-flow is a darn good filter system and for sure wouldn't hurt your air intake any...Sorry If I have misinformed you.......Have fun with your new saw...... Here's one for the "tree huggers"......I have a wind deflector on my pickup that reads...."HUG A LOGGER....you'll never go back to trees !"

 

[Drew78]

Stihlfast-

Forgive me, but in your reply are you saying you are running your saws at 14,800 (14.8) RPMS for break in? Then leaning them out to 16,800 (16.8)?
What saw are you doing this on? A 460?
Heck I have my 460 set to 13,390 right now on the top end.

Can a ported saw take that much more revs?!

-drew

 

[bwalker]

A ms 460 would turn into a mini chenrobyl if it was reved out to 16,800 rpms.

 

[stihlfast]

Drew78

: Oh my goodness have I stirred some controversy ?....In any case.....Yes you heard right.....I tach my hopped-up 460 mag Stihl to 14,800 new and lean to 16,800 rpm when broke in......and they last about a year and a half....sometimes two....That is the whole idea behind a ported saw is that you can turn them at amazing rpms........I am a cutter for a helicopter company and we usually work on some pretty steep ground....you have to be able to get the tree off the stump when your on 60% slopes and better...(wind gusts play a big part.....especially in high altitudes......is why speed is an important issue for me personally......and the reason for the rpms and race version chains......(which is a whole differen't subject).....If you find it hard to believe that a saw can turn them r's ......you might want to give a call to "Steve's saw service" in Lolo Montana.......The phone # is 1-406-273-6231 and ask them about thier hop-ups......They would be more than happy to help you......
You may not be getting the full power potentual out of your saw otherwise..........Just a thought.....
Mark

 

[HUSKYMAN]

Full potential for me is getting my saw to last more than a year and a half

 

[stihlfast]

Ben Walker

Ben.......In case you didn't get the phone #.........Here it is ......(STEV'S SAW SERVICE).....1-406-273-6231

They might be able to ........lets say.....broad'n your horizons.... on just how many RPM's a saw can turn
(LOL).........
Mark.

 

[stihlfast]

HUSKYMAN

Yea...I see our point......That is a drawback.....The saws don't last near as long as stock ones.....A person still gets alot of cutting done in the life of one though.....But like you said..... a year and a half isn't much....With money as tight as it is these days it can get pretty expensive I must admit.....But my job pretty much demands that I have that type of saw....It does kinda suck though.....It seems every time your turning around your buying a new saw.....but man they sure are fun......(while they last )
Mark.

 

[HUSKYMAN]

Well Mark at least with your method you get to try out all the new saws every year. Either you are not married or you dont have to pay for them yourself, because that would never fly for the rest of us!

 

[Jacob J.]

Huskyman- I don't know which company Stihlfast works for but when I was working for Columbia, they pay cutters a "saw rent" everyday which is above and beyond your cutting wages, depending on the job, unless you're a day tramp, then it's one lump payment. I save my saw rent out from my scale and use it to buy or repair equipment. We also get extra scale when we use our own jacks, which works well if you get into some big sticks, you can jack three or four big trees and make a good scale at the jack rate, and then cut a bunch of smaller timber to bring your diameter average down and that raises your scale price.