Echo 4910 - Now at elevation - 7600 ft.

[EvoOneMkVIII]

Hi All,
Awhile back I requested info on my "second chainsaw" purchase, the first being a 10 year old Husky 445. Oddly enough the Husky was NEVER adjusted for my move from 500 ASL ft to my current 7600 ASL feet, and I'd say it runs pretty fine. At worst I'm sure it's a bit rich.
But anyhow, to my new purchase. I wanted something with potential but not a big investment. Ergo, the Echo 4910, which seems to have an OK level of satisfaction. But then again, I wiffed on the altitude adjustment. Brand new, not even one tank through it, does not idle worth shazam.
(I know I know, at some soon point I'll want to get the limiter caps off and have the option of fully tuning.)
Maybe i should have gone for an ecarb to do that adjusting for me. But it would seem that, with EPA requirements making EVERYTHING lean, I might be able to do whatever adjusting that needs to be done withing the range of the H, L, I screws because since I'm at altitude it's no doubt running rich.
The Echo manual says don't touch adjustments until two tanks of gas have been used.
Caveat: I'm not a mechanic, but I used to adjust the valves on my Honda 300 Dream (now that is dating me), and I can usually follow instructions.
I'm also open to learning of some small engine guy in SantaFe, if anyone knows of a guy that can do this and also help me make it run better once broken in.
I suspect this is a pretty simple op and would appreciate any guidance. I do have download the 4910 service specs so I have that as a reference point.
So far I've cut down two small trees and limbed, and bucked them. And it runs fine when on the throttle, but off, it just dies.
I also figured out my bar/chain lube issue, with it seeming not to feed at first so I opened it wide, and then a few minutes later it's spewing oil like Old Faithful. So back to reversing that wide open position.


Appreciate any help you might have.
Thanks, Rob

 

[EvoOneMkVIII]

Or maybe this means I need to go out an also buy an e-carb setup...Any excuse?

 

[EvoOneMkVIII]

Or maybe this means I need to go out an also buy an e-carb setup...Any excuse?

Responding to my own post ....
With 1/2 tank used so far, should I just mess with the idle screw for a few tanks?
And do I need the spline wrenches or will a slotted screwdriver do until the limiters are out?

 

[Parkerpusher]

I would feel comfortable going ahead and tuning the saw right away to get it to run right. Maybe just stay within the limiters for a few tanks or until you think it’s broken in and then tune it again. There’s no harm from tuning it now, especially just the idle.

 

[esean]

Adjust the carb now. Make sure its just rich enough to four-stroke out of the cut but smooth out once you hit wood. If it still won't idle adjust the lo screw and/or increase the idle speed.

 

[EvoOneMkVIII]

I've not taken a look at the adjusters but are they the splined things or a slotted small screwdriver will do? That is, with limiters in place?

 

[ericm979]

My Echo CS352 had slotted screws with limiters. For my elevation (2000') it was way lean even though it was tuned to as rich as the limiters would allow. It ran ok but felt and sounded lean. I removed the limiters, trimmed the tabs and reinstalled them. The remains of the limiters make it easier to find the slot with the screwdriver.

Basic carb adjustment procedure is to tune the low speed for max rpm, adjusting the throttle stop to keep rpms around 2500-2800. That's low enough that the clutch does not engage but high enough to idle smoothly. Once max rpms are reached, the low speed mixture is richened slightly. This makes it run smoother and start easier.

Then you tune the high speed for the specified rpm or so that it four strokes when lifted in the cut. If the low mixture is set correctly then there should be no stumbling or hesitation when the throttle is opened.

Stihl shop manuals for carbed saws cover this pretty well. Some of their regular owners manuals do too. The default settings will be different for your saw of course. For this saw with limiters I'd start fully rich and lean it from there.

 

[EvoOneMkVIII]

My Echo CS352 had slotted screws with limiters. For my elevation (2000') it was way lean even though it was tuned to as rich as the limiters would allow. It ran ok but felt and sounded lean. I removed the limiters, trimmed the tabs and reinstalled them. The remains of the limiters make it easier to find the slot with the screwdriver.

Basic carb adjustment procedure is to tune the low speed for max rpm, adjusting the throttle stop to keep rpms around 2500-2800. That's low enough that the clutch does not engage but high enough to idle smoothly. Once max rpms are reached, the low speed mixture is richened slightly. This makes it run smoother and start easier.

Then you tune the high speed for the specified rpm or so that it four strokes when lifted in the cut. If the low mixture is set correctly then there should be no stumbling or hesitation when the throttle is opened.

Stihl shop manuals for carbed saws cover this pretty well. Some of their regular owners manuals do too. The default settings will be different for your saw of course. For this saw with limiters I'd start fully rich and lean it from there.

 

[EvoOneMkVIII]

Very helpful information everyone! Digging into my Echo manual, it's not bad.
I'd appreciate some insight on my thinking on the adjustment limiters - with the EPA mad about leaness, and being at 7600 feet, am I likely correct that I will have all the adjustment I need without removing the limiters? The difference between sealevel and +7600 likely gives me a huge richness shift, right?
I've watched some of the limiter removal videos, and the guys that make them know the process so well they don't provide much detail on tab removal and how you get the caps off without doing damage, if that's an issue.
Echo manual says for tuning:
Warm up
Turn H adjuster CCW to stop
Turn L adjuster midway between full CCW and CW stops
Start engine: turn idle (T) CW until chain starts to move,
then turn CCW until chain stops moving; then turn CCW another 1/4 turn
Accelerate to full throttle 2-3 seconds, back off, then accelerate again to FT,
If hesitation, turn L 1/8 turn CCW; test and adjust again, until smooth transition.
Check idle speed, readjust as necessary.
But nothing further about H speed adjustment.
If anyone is great at coaching a budding saw tuner, I'd appreciate a phone call to walk me through it. I will watch more YouTube videos on this topic.
The Echo instructions, for me, are missing any real reference to H speed adjustment, and that is where one gets four-stroking off load, and then getting down to biz when under load.
Alternatively,if anyone has a must watch youtube video that covers Echo stuff, or is applicable, name it away.
Thanks, Rob
Thanks,

 

[snobdds]

I'm even higher than you and my saws need to be leaned out a little more to compensate for the lack of oxygen. Not much, maybe a quarter turn.

I have a tack and if I set the saw to factory settings, it's way too rich. At altitude, we just have to put up with saws that don't rev as high at sea level.

Just FYI

 

[EvoOneMkVIII]

I'm even higher than you and my saws need to be leaned out a little more to compensate for the lack of oxygen. Not much, maybe a quarter turn.

I have a tack and if I set the saw to factory settings, it's way too rich. At altitude, we just have to put up with saws that don't rev as high at sea level.

Just FY

Thanks for info, and when you say leaned out is it both H and L or just H speed?

 

[snobdds]

Thanks for info, and when you say leaned out is it both H and L or just H speed?

It's both.