Cs-590 5500-11000ft? Carb adjustment

[Squatchsaw]

Hi All,
This is my first post here and I did read the one high altitude thread, but it did not really answer what I needed to know.

I have just bought a cs-590, half a tank of gas in it thus far. I live at 5500ft and typically cut fire wood up to 11000 in remote areas.

My question is once I do run two tanks of fuel through the saw( if that's not a problem at say 9-10000ft) for a brand new saw, what the do I need to be doing to adjust the carburetor? Is this turning L/H in and leaning out, or turning them out to richen?

With the little I have cut thus far, the throttle needed some feathering past bogging to get it going, then it ran like a champ.
I bought this to replace a poulan 5020av, it's not running for squat and I just checked the piston is scored. Needless to say I do not want a good saw to be damaged.


Thank you for any guidance you can give to help me keep my saw healthy!

 

[beaglebriar]

Clockwise to lean , counterclockwise to richen. Madsen's has a good write up on saw tuning.
I don't work on echo's much but whatever it has for adjustment limiters, ditch them. You're probably going to have to make somewhat drastic changes at that high altitude unless it has already been tuned for it. Mix your gas at 40:1 to 32:1 regardless of the manufacturer recommendations.

Disclaimer: I've never ran a saw at that high altitude. Probably someone here that does regularly with better input. @jacob j. will have some valuable knowledge to pass on I'm sure.

 

[Squatchsaw]

To clarify, why would I want to step from 50:1 mix, isn't higher oil protecting the saw?

Also would I be leaning out a saw for high elevation or richening it?

Thank you

 

[popopboat]

50:1 or 1 part of oil per 50 parts of fuel, that is leaner than lets say 1 part of oil per 32 parts of fuel, smaller number = richer mix.

Higher attitude = thinner air, which requires less fuel = clockwise

But i wouldnt recommend adjusting carburetor by yourself if you dont well understand how it works.

 

[Squatchsaw]

I have watched some videos and had made some adjustments at 5500ft to the last saw. I understand the Low side and getting to a sweet spot with good throttle response. The high side I have ever adjusted in the wood, but I do understand what I'm listening for to get it to 4 stroke out of the wood and clean up once I'm cutting.
The last saw wasn't doing well before I was making adjustments, there was definitely a too far in and too far out on the low side. Right in the middle of that sounded better than it had ever ran.

Am I harming the saw running the two tanks of gas through it, at any higher elevations, before making adjustments ( per the manufacturer )?

You said the smaller then number the richer the mixture, hense more gas to less oil.
Am I mistaken to assume a 40:1 fuel being richer, is then not what I want for higher elevation, or have I mixed something up here?

I appreciate you giving the patience while I'm learning from you here.

 

[drf256]

Think there is some misunderstanding about rich tune vs richer oil.

50:1 is 50 parts fuel to 1 part oil. 32:1 is 32 parts fuel to 1 part oil. So 32:1 has more oil in it than 50:1. The 50:1 was promulgated by the EPA. It produces less emissions than mixes with more oil in them. It’s generally accepted that even with the newer oil technology, 40 or 32:1 will increase saw life from better lubrication. Back “in the day” we ran 30W motor oil at 16:1 in many motors including outboard boat engines. I remember the oil slick behind our duck boat…

Rich saw tune is interdependent on which mix you are using. Some oils burn and contribute to combustion power and some don’t. Some oils are very viscous and decrease the flow through the carb jet. This is why one really needs to tune for their own mix at their own elevations.

At higher elevations, one needs to tune leaner. The air isn’t as full of oxygen. When we did the 066 buildoff i drilled my carb jet. Im at 230 ft ASL. At Randy’s house, we were at 2300 asl and my saw wouldn’t run past 10k with the H needle buried. I needed to buy a new carb while there.

Most saws are tuned super lean by the factory. My bet for you is that you’ll be running fine with more oil and some adjustment of your H needle. You need to learn to tune by ear It’s the safest.

This is why AT saws have become so attractive. You just run them without a worry most times.

Sorry for the long response and hope this made some sense.

 

[Squatchsaw]

On the contrary, thank you for clearing up my misunderstanding, I am a bit out of my wheelhouse on small engines. I will get a good clean non ethanol gas and mix it to the recommend 40:1. Currently I have poulan, husqvarna, and echo oil. Does anyone recommend any specific oil that burns or does not burn well, are either better suited per my use?

Also, am I correct in thinking the L side adjustment will give me my throttle response, or will that also be effected by the H side, once I'm at higher elevation. It took a couple braps of the trigger to get the saw not to bog, then once rpm was a tad higher it ran fine with the throttles response.

I appreciate all the info given, I have learned even more than I thought I would, thank you!