Adjusting new Echo CS-590 at High Altitude

[cao-2000]

I have a new CS-590 coming and live at 4500 feet elevation. I use Tru-Fuel, like in my other 2 cycle equipment.

Wanted to get some advice on doing some minor carb tuning to get the most out of the chainsaw. I am not currently looking at other mods like muffler, porting, coil, etc.

My plan was to run it with a couple of tanks of gas, then remove the carb H/L limiters and adjust according to the service manual and a tach.

I guess here are my questions:

1. Is there a high altitude procedure? I didn't see anything in the service manual
2. Should I run 2 tanks of gas before attempting any carb adjustment?
3. I have seen people replace the high jet on the Walbro carb with one that allows more leaning out. Is that something I should consider putting in? The replacement jet is part number 86-578-1.

Thanks,

Chris

 

[farminkarman]

I have a new CS-590 coming and live at 4500 feet elevation. I use Tru-Fuel, like in my other 2 cycle equipment.

Wanted to get some advice on doing some minor carb tuning to get the most out of the chainsaw. I am not currently looking at other mods like muffler, porting, coil, etc.

My plan was to run it with a couple of tanks of gas, then remove the carb H/L limiters and adjust according to the service manual and a tach.

I guess here are my questions:

1. Is there a high altitude procedure? I didn't see anything in the service manual
2. Should I run 2 tanks of gas before attempting any carb adjustment?
3. I have seen people replace the high jet on the Walbro carb with one that allows more leaning out. Is that something I should consider putting in? The replacement jet is part number 86-578-1.

Thanks,

Chris

@Red97 @Mastermind

 

[Mastermind]

@Red97 @Mastermind

Joe is better on this model.

 

[Red97]

You should be able to pull the limiters and get a good tune on a stock saw. Should not need to swap the nozzle

 

[cao-2000]

You should be able to pull the limiters and get a good tune on a stock saw. Should not need to swap the nozzle

Thanks, I’ll give that a go.

Should I run a couple of tanks of gas through before adjusting?

 

[huskihl]

Thanks, I’ll give that a go.

Should I run a couple of tanks of gas through before adjusting?

Elevation makes them run rich. I’d trim the limiters right from the get-go. Tune it so it 4 strokes (burbles) out of the wood and cleans up in the wood

 

[North by Northwest]

All things being equal quality gas , oil , clean air filter , full tank of fuel . Tune the saw in the cut with a quality tach . It should 4 stoke out of the cut then clean up once in the wood . Run a tank through it , through some hardwood , do a plug check . It should show tan to medium Brown coloration depending on your fuel to oil ratio !

 

[cao-2000]

Any particular RPM range I’m looking for in the cut (or free run)?

 

[North by Northwest]

Any particular RPM range I’m looking for in the cut (or free run)?

Hey brother , your new saw is a fine firewood saw at a bargain basement price congratulations ! Unfortunately your saw is set at the factory for adjustability of jets to approx 1100 ft . At your altitude as Kevin mentioned , its going to be running rich . Once you remove the limitors , you will be able to retune the saw in the cut as previously mentioned . MWOT for your saw is around 12, 500 rpm. I never push it that high on the tach . In the cut all depends on what type & size chain your running . The more teeth or aggressive full chisel will drop your achievable rpm accordingly . I would think in the cut with semi skip 11, 500 would be optimism . Full house perhaps 10,500 . In the cut is what matters brother . It should 4 stroke a little then clear up in the cut accordingly . Feel free to pm me if needed cheers !

 

[cao-2000]

Finally got my saw, I will review all the advice and see if I can get this thing adjusted!

 

[cao-2000]

Got my carb adjusted and it runs better now. Thanks for all the advice.

Hardest part was just getting the slotted head screwdriver to find the plastic screw head through the rubber access holes!