Qatanlison
ArboristSite Member
I just wonder if you adjust the carburetor with or without bar and chain on.
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Carb. adjustment
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mboln52000
ArboristSite Operative
low speed wouldnt matter. Idle speed, and high speed you need the bar and chain on.
I like to set my high speed idle while the saw is cutting, under a load, with a digi tach.
I like to set my high speed idle while the saw is cutting, under a load, with a digi tach.
mboln52000
ArboristSite Operative
This is how i do my rebuilt saws:
Initially I set my high speed idle on the bench, or out in the yard,(thats only after midnight, if i am sure the neighbors are asleep) just to dial it on. I use a digital handheld tachometer. Stihl makes a really nice, pocket caluclator sized model.
Alot of people here set them up by listening to the sound, for the 4-stroke blubber, but that just isnt my method.
You can hold the tach in your left hand as you hold the handlebar while revving, and read the rpm you are turning, If its low, i turn the high speed screw till i get the desired rpm.
That gets me close that way.
Then once the saw is broke in, a few tanks of gas through it, i will check the rpm's in the cut.
I have a nice ash log out back, about 30" diamter or so, and i start a cut with a fresh chain and check the rpm with the tack like before. Its allways a few throusand off and i havent seen one yet that didnt need turned up.
I just did a 036 last weekend, and its turning 13,500 rpm, in the cut.
Yes, it will be overrevving if you arenot in the cut, but why would you run the saw wide open if not in the cut?
Thats my logic anyway. I havent had any bearing failures yet.
Matt
Initially I set my high speed idle on the bench, or out in the yard,(thats only after midnight, if i am sure the neighbors are asleep) just to dial it on. I use a digital handheld tachometer. Stihl makes a really nice, pocket caluclator sized model.
Alot of people here set them up by listening to the sound, for the 4-stroke blubber, but that just isnt my method.
You can hold the tach in your left hand as you hold the handlebar while revving, and read the rpm you are turning, If its low, i turn the high speed screw till i get the desired rpm.
That gets me close that way.
Then once the saw is broke in, a few tanks of gas through it, i will check the rpm's in the cut.
I have a nice ash log out back, about 30" diamter or so, and i start a cut with a fresh chain and check the rpm with the tack like before. Its allways a few throusand off and i havent seen one yet that didnt need turned up.
I just did a 036 last weekend, and its turning 13,500 rpm, in the cut.
Yes, it will be overrevving if you arenot in the cut, but why would you run the saw wide open if not in the cut?
Thats my logic anyway. I havent had any bearing failures yet.
Matt
jokers
Addicted to ArboristSite
What do you do Ola?
Russ
I get it now. What you are calling high speed idle is the actual engine speed in the cut.
I wouldn't rev my saw full open unless I'm in a cut or tuning. But there's been many a time where you hit rotten wood and your saw will hit full rev's.
If your bottom end is holding up, must be OK. How much gain are you getting for setting the engine this way?
mboln52000
ArboristSite Operative
To me, I see a big difference in speed through the cut. I really dont have any data to back it up, but i would say based on running the same saw before i turned it up, and then after, on the same log, its about 30% faster.
I do that on my bucking and felling saws.
My 024 that i use for trimming/limbing i leave on the low end of the setting. It only turns about 9 or 10,000 rpm. I leave it low because i am always overreving when removing branches.
I know what you mean about hitting a spot of dead wood, and the rpms shoot up. That hasnt been a problem, but if run into it a lot i just have to back off the throttle.
Have you done any muffler mods on that 046,or the 034 super?
They help with the higher rpms, and keeping things a little cooler.
I do that on my bucking and felling saws.
My 024 that i use for trimming/limbing i leave on the low end of the setting. It only turns about 9 or 10,000 rpm. I leave it low because i am always overreving when removing branches.
I know what you mean about hitting a spot of dead wood, and the rpms shoot up. That hasnt been a problem, but if run into it a lot i just have to back off the throttle.
Have you done any muffler mods on that 046,or the 034 super?
They help with the higher rpms, and keeping things a little cooler.
Qatanlison
ArboristSite Member
Russ,
I rely on my ear and feel. My question was raised when I realized that a saws max rpm is true for an unloaded saw, without bar and chain that is. I guess it's not that big of a deal but a saw with the carburetor adjusted with bar and chain on would actually be a bit on the lean side.
For the low speed screw I let the saw idle for some 10s and then I turn it upside down to make sure it's not getting too much fuel - if the saw dies when turned there is an excess of fuel under the cyl. I set the high speed to where it starts to flutter. When done I try the "feel", does it respond without hesitating? Does it pull good in the cut and so on...
O
I rely on my ear and feel. My question was raised when I realized that a saws max rpm is true for an unloaded saw, without bar and chain that is. I guess it's not that big of a deal but a saw with the carburetor adjusted with bar and chain on would actually be a bit on the lean side.
For the low speed screw I let the saw idle for some 10s and then I turn it upside down to make sure it's not getting too much fuel - if the saw dies when turned there is an excess of fuel under the cyl. I set the high speed to where it starts to flutter. When done I try the "feel", does it respond without hesitating? Does it pull good in the cut and so on...
O
Thanks for sharing your great info. 30% gain is substantial. I hate admit it, but my snap-on digital tach is acting up.
I have not modded my 046 or 034 super yet. Just finished with my 335 and are real pleased with the gain. (a little loud)
I'm planning on doing the 046 next. I would like to do my own mod VS buying one from the dealer.
I'm running a 20" bar now and you almost cannot bog it down. I sure like that 20" on my 046. But I do need to get at least a 24" for those few occassion you need a little extra.
I know once I put a longer bar on 046, it's going to be used only for the larger cuts VS pulling it out for most duties.
I have not modded my 046 or 034 super yet. Just finished with my 335 and are real pleased with the gain. (a little loud)
I'm planning on doing the 046 next. I would like to do my own mod VS buying one from the dealer.
I'm running a 20" bar now and you almost cannot bog it down. I sure like that 20" on my 046. But I do need to get at least a 24" for those few occassion you need a little extra.
I know once I put a longer bar on 046, it's going to be used only for the larger cuts VS pulling it out for most duties.
Lawn Masters
Addicted to ArboristSite
I tuned my Jonsered 670 with just a screwdriver and the bar and chain on it, I tuned it till it revved up with no hesitation and it runs a little rich at high speed but not too rich. no problems to date reported by me, I must know what I'm doing.
mboln52000
ArboristSite Operative
There are probably not to many people on here who tune a saw the same way. I havent seen one way thats superior to another way, just different. Of course, we all think that our own way is the best. Like they say...To each, his own.
If you can tune the saw your way, and it holds together, and doesnt disenigrate, then your way is working.
If i trash a main bearing or piston, big deal. I learned something and will repair it and go on.
I will be a happy guy when i have one hitting 20,000 rpm, and i have a project saw i think i can make it happen on.
046,
I would open up those mufflers on the 046 and the 034. That 046 will really like that 20" bar then, you will have more than enough power to handle it.
My 036 pulls a 20" with no bogging through some really tough oak. It has a modded muffler. So your 046 would eat it up!
If you can tune the saw your way, and it holds together, and doesnt disenigrate, then your way is working.
If i trash a main bearing or piston, big deal. I learned something and will repair it and go on.
I will be a happy guy when i have one hitting 20,000 rpm, and i have a project saw i think i can make it happen on.
046,
I would open up those mufflers on the 046 and the 034. That 046 will really like that 20" bar then, you will have more than enough power to handle it.
My 036 pulls a 20" with no bogging through some really tough oak. It has a modded muffler. So your 046 would eat it up!
tony marks
Addicted to ArboristSite
adjustin a carb to me depends on the saw.. example ,,my 372 can be set at 13900 and will cut good and hold rpm well.. however its an high rpm saw and in playin with it ,..ive foundu setting it at about 14100 cold ,will run it to 14250
after shes been used a bit.. for this saw
with 20 inch bar,, i get rite smart more cutting speed a that setting and just listen to the power band...then after shes been cutting a while ,,i dont have to pay it much attention ,,as she holds torque at that setting,,and cuts a good bit faster..the wood im using is 25 inch inch cured hickory ,with the bar sunk to the hilt.. i figure with setting it in that hard a wood .. she oughta have an easy time with green wood and soft wood..
this is just my opinion .. another reason i leaned it out a bit was my plug was almost too dark a brown color. any more an it woulda been black..
ps there was questions as to whether a plug will go bad.. and yes the old plug had thisun skipping pretty bad..
so they do go bad..altho it was probably the plug it was sold new with it..
after shes been used a bit.. for this saw
with 20 inch bar,, i get rite smart more cutting speed a that setting and just listen to the power band...then after shes been cutting a while ,,i dont have to pay it much attention ,,as she holds torque at that setting,,and cuts a good bit faster..the wood im using is 25 inch inch cured hickory ,with the bar sunk to the hilt.. i figure with setting it in that hard a wood .. she oughta have an easy time with green wood and soft wood..
this is just my opinion .. another reason i leaned it out a bit was my plug was almost too dark a brown color. any more an it woulda been black..
ps there was questions as to whether a plug will go bad.. and yes the old plug had thisun skipping pretty bad..
so they do go bad..altho it was probably the plug it was sold new with it..
Shade
ArboristSite Member
mboln52000, what keeps your saw from running lean when you tune it to max rpm in the cut?
the way I understand it, the leaner the carb is set on the high end, the faster the saw runs. Also if it is too lean, it robs power, and runs hot.
Isn't setting it your way forcing the saw to run lean, though I do agree, as long as it isn't blowing up, it's all good...
the way I understand it, the leaner the carb is set on the high end, the faster the saw runs. Also if it is too lean, it robs power, and runs hot.
Isn't setting it your way forcing the saw to run lean, though I do agree, as long as it isn't blowing up, it's all good...
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Is this 036 modified? If it isn't then wouldn't 13,500 in the cut be on the lean side?
You check the saw out of the cut after you have adjusted it in the cut to be sure that you are not exceeding the rpm specs. for the saw. Am I missing something here?
mboln52000
ArboristSite Operative
Shade and Rich,
Yes, you are both corect, it is running a little lean on the high side. I try to compensate for that but running the low speed a little richer, since it supplies about 30% of the fuel at WOT.
I did remove the muffler last weekend on it, and the 066. Both pistons/cylinders look like new, even after a season of cutting with them tuned this way.
Yes, they do over rev, and run very lean if they are not in the cut, but i try to avoid that situation as much as possible.
I need to build in a tach on my top cover! That would be a cool mod!
Rich, it is a modded saw, sort of. Port matched muffler/gasket/manifold. High comp base gasket (piece of .005 paper), dual port muffer.
I have a very cool mod to do to another 036 pro over the summer. I will post pics and details of that one, if it all works out as i plan.
Matt
Yes, you are both corect, it is running a little lean on the high side. I try to compensate for that but running the low speed a little richer, since it supplies about 30% of the fuel at WOT.
I did remove the muffler last weekend on it, and the 066. Both pistons/cylinders look like new, even after a season of cutting with them tuned this way.
Yes, they do over rev, and run very lean if they are not in the cut, but i try to avoid that situation as much as possible.
I need to build in a tach on my top cover! That would be a cool mod!
Rich, it is a modded saw, sort of. Port matched muffler/gasket/manifold. High comp base gasket (piece of .005 paper), dual port muffer.
I have a very cool mod to do to another 036 pro over the summer. I will post pics and details of that one, if it all works out as i plan.
Matt
Crofter
Addicted to ArboristSite
deliberately lean
Matt, it seems you know you are courting problems by running so lean. If you are willing to take the risk that is fine but you should put a disclaimer in there and not be so freely recommending the procedure. Many little things can occur that would further lean the mixture temporarily(such as air leaks or dirt) and before you knew it you could do serious damage. Just because you have got away with it so far does not make it a good practice in my opinion.
Frank
Matt, it seems you know you are courting problems by running so lean. If you are willing to take the risk that is fine but you should put a disclaimer in there and not be so freely recommending the procedure. Many little things can occur that would further lean the mixture temporarily(such as air leaks or dirt) and before you knew it you could do serious damage. Just because you have got away with it so far does not make it a good practice in my opinion.
Frank
mboln52000
ArboristSite Operative
Frank is right
True, i should have put a statement in there, and your right, it isnt for everybody. If you get it a little too lean, you will score the cylinder, and probably wipe out the big and small end bearings too.
My set-up is not factory recomended, and it will void any and all warranties.
I only run that way because it really doesnt bother me if I trash a cylinder or bearing. I wrench for fun, its an outlet, a hobby. I have been doing small engines, or just plain engines for around 20 years now, and i pretty much know what i am doing.
I like to experiment, swap parts, modify this muffler, an air filter, etc, and see what gains/failures happen.
I should have mentioned all that too.
So, my disclaimer is...Tuning is your own risk! Do what works for you.
True, i should have put a statement in there, and your right, it isnt for everybody. If you get it a little too lean, you will score the cylinder, and probably wipe out the big and small end bearings too.
My set-up is not factory recomended, and it will void any and all warranties.
I only run that way because it really doesnt bother me if I trash a cylinder or bearing. I wrench for fun, its an outlet, a hobby. I have been doing small engines, or just plain engines for around 20 years now, and i pretty much know what i am doing.
I like to experiment, swap parts, modify this muffler, an air filter, etc, and see what gains/failures happen.
I should have mentioned all that too.
So, my disclaimer is...Tuning is your own risk! Do what works for you.
tony marks
Addicted to ArboristSite
13500 in cut.. what u cuttin broom straw..i may be wrong but i dont think nothin would hold that rpm in the hickory i cut today..id have to see that.. but i wouldnt wanta be standin too close to a saw that would do that..
mboln52000
ArboristSite Operative
Tony,
Thats cutting green ash and pin oak lately. Sometimes cherry, and maple, but i have to let off the gas a little then, cuz they are so soft.
We dont have any real soft woods round here. Mostly all oak varieties, tulip, cherry, ash...and lots more ash, but not for long thanks to our wonderful importations as of late!
Thats cutting green ash and pin oak lately. Sometimes cherry, and maple, but i have to let off the gas a little then, cuz they are so soft.
We dont have any real soft woods round here. Mostly all oak varieties, tulip, cherry, ash...and lots more ash, but not for long thanks to our wonderful importations as of late!
jokers
Addicted to ArboristSite
Ola,
I always perform carb adjustments with the bar and chain on. I don`t know what your background is, or if you have been at this for long, but somewhere in the past it was ingrained in me that the bar and chain must be installed to provide a nominal baseline load for "no load" max rpms which will require different screw settings for vastly different bar lengths. Also many steps in the tuning process reference a turning chain. Unfortunately I cannot locate any reference to back me up. What I can tell you is that in Husky owners manuals and workshop manuals it tells you right up front that the bar, chain, and side cover must be installed when adjusting the carb to prevent the clutch from walking off when the engine decelerates.
Another thing that I can say is that a spec of 13,500rpm is a no load spec, ie: the saw is not expected to pull that in the cut with the porting that they leave the factory with. Max power is generally between 9,000-9,500 rpm and if your stock saw is pulling 13k in the cut, you need to lower your rakers or sharpen your chain, or both. BTW, this bit of wisdom is for mboln.
Russ
I always perform carb adjustments with the bar and chain on. I don`t know what your background is, or if you have been at this for long, but somewhere in the past it was ingrained in me that the bar and chain must be installed to provide a nominal baseline load for "no load" max rpms which will require different screw settings for vastly different bar lengths. Also many steps in the tuning process reference a turning chain. Unfortunately I cannot locate any reference to back me up. What I can tell you is that in Husky owners manuals and workshop manuals it tells you right up front that the bar, chain, and side cover must be installed when adjusting the carb to prevent the clutch from walking off when the engine decelerates.
Another thing that I can say is that a spec of 13,500rpm is a no load spec, ie: the saw is not expected to pull that in the cut with the porting that they leave the factory with. Max power is generally between 9,000-9,500 rpm and if your stock saw is pulling 13k in the cut, you need to lower your rakers or sharpen your chain, or both. BTW, this bit of wisdom is for mboln.
Russ
