Echo 590 Timberwolf "H" setting

[Red97]

Set it way rich on the high side and lean it out. 590 is typically easy to hear. Especially if you do a simple muffler mod.

 

[lostone]

Set it way rich on the high side and lean it out. 590 is typically easy to hear. Especially if you do a simple muffler mod.

It's got a muff mod. done. Even my son who's hearing is fine could barely tell. I will give it a try again this weekend maybe I just wasn't leaning it out enough. I need to check the Low setting anyway I am wondering if the limiters where spinning in there some and making the adjustments seem more than what I was going. I will probably just remove the limiters completely and just use the ends of the jets for adjusting.

I was going to remove the muffler when changing out the diverter but after getting the bolts out about a turn or so it became very difficult to turn them and I didn't want to break or strip something so I just put them back in. I would really like to get them out. I ended up just removing the chain brake and then changing out the diverter to one I had cut the deflector out of.

 

[Red97]

Sounds like you may be on the limiter. They have almost no studder, but will not rev any faster and let the saw run away.

Richen it up then slowly lean it back in. Take a video So we can hear it.

 

[lostone]

Will try to take a vid this weekend, If I lean it out I can get more rpm out of it but just not sure on this saw if I am still four stroking since it sounds smoother than my 036.

 

[Red97]

This was before I figured out the carb mod. Way way rich but you can definitely tell when it cleans up in the second cut.

 

[lostone]

thanks Red, ya she is still four stroking. I will have to lean it out some more.

 

[jonsereds 621]

Anyway old one out and new one in place, have everything put back together but it is getting late so I will be testing it out tomorrow.

I have a similar problem with an 026, would anyone care to explain just how to remove this Hi jet (without damage) as this carb has "something" lodged in there giving me a lack of further high. Saw runs fine on AM carb, but I don't like the way throttle butterfly is attached.

 

[Lovesaws]

The goal is to block the hole in the bottom of the jet. The stock jet has to be in the correct position to line up with the feed hole in the carb body.

The 19X jet has a band machined and 2 feed holes to allow fuel flow regardless of the index. Just has to seat at the right depth, which has a bit of play as well.
Feel trying to insert a screw could allow debris to block the feed passage/damage the check valve.

Swapping the jet
Literally a 5-10 min job on the 590.

Remote AF cover/filter
Undo fuel/impulse
2 bolts (t27) to remove the carb
4 screws to remove bottom cover (metering/wet side).
Pin punch with flat face the jet into carb bore
Open throttle plate remove old jet
Tap in new jet
Reinstall.

Enjoy fully adjustable 590 carb

Does this work in the 620 to I’m having a terrible time trying to tune this thing and iv never had trouble tuning a saw before!!

 

[9050LX]

The carb on the 590 is a bit different than most saws, having the H 1/2 a turn out is not uncommon. In fact the saw will still run OK with the needle fully seated. If you're saw doesn't have any underlying problem, it will be running dog rich with the H turned out 3 full turns.

Mines out 3/4 of a turn. Weird one to tune.

 

[Red97]

Does this work in the 620 to I’m having a terrible time trying to tune this thing and iv never had trouble tuning a saw before!!

Typically not needed on a stock saw, or muffler modded.

What is yours doing?

 

[Lovesaws]

Typically not needed on a stock saw, or muffler modded.

What is yours doing?

Mine is dual port mm I had reed make me one but any ways saw ran great pulled hard just started actin up so tore carb down sure enough was in carb so took it a part cleaned it and I cannot get it to run like it did before iv turned jets and pulled rope till my arms fell off haha

 

[Lovesaws]

Mines out 3/4 of a turn. Weird one to tune.

You got that right !!

 

[Red97]

L should be 1.5 turns out h around 1 and move from that.

 

[lostone]

Mine is dual port mm I had reed make me one but any ways saw ran great pulled hard just started actin up so tore carb down sure enough was in carb so took it a part cleaned it and I cannot get it to run like it did before iv turned jets and pulled rope till my arms fell off haha

When you cleaned it out did you used compressed air to dry/blow it out also?

It's been awhile since I worked on the 590 carb mod and I cannot remember if this carb has the check valve in it's design or not, but I vaguely remember it having one. Anyone who has worked on the older SDC and HDC carbs knows where I am going with this. Some carb design's have a check valve in them and if hit with air from a blow gun can destroy the check valve, it's nothing more than a piece of diaphragm designed to work with the pulse of the engine and if it gets damaged will cause hard starting, reluctance to prime and irregular run characteristics which make it impossible to tune or get the saw to keep a tune since it will not pulse correctly. I see this a lot with the McCulloch and Homelite saws, people will clean/rebuild the carb and it still doesn't want to run correctly or even want to start because the check valve has been damaged (which isn't included in most rebuild kits). Again I'm not sure if this carb has it or not and I know some carbs still have this design.

 

[cheeves]

Good thread! I'm all ears whenever people in the know talk tunning.

ANDY....IS ONE OF THE BEST ON HERE...FOR YEARS !

 

[Lovesaws]

When you cleaned it out did you used compressed air to dry/blow it out also?

It's been awhile since I worked on the 590 carb mod and I cannot remember if this carb has the check valve in it's design or not, but I vaguely remember it having one. Anyone who has worked on the older SDC and HDC carbs knows where I am going with this. Some carb design's have a check valve in them and if hit with air from a blow gun can destroy the check valve, it's nothing more than a piece of diaphragm designed to work with the pulse of the engine and if it gets damaged will cause hard starting, reluctance to prime and irregular run characteristics which make it impossible to tune or get the saw to keep a tune since it will not pulse correctly. I see this a lot with the McCulloch and Homelite saws, people will clean/rebuild the carb and it still doesn't want to run correctly or even want to start because the check valve has been damaged (which isn't included in most rebuild kits). Again I'm not sure if this carb has it or not and I know some carbs still have this design.

Thanks I cleaned the carb with carb cleaner no air but still possibility thanks sir!!

 

[9050LX]

Back from the dead.I bought a non-running 590, installed a new piston and some small items.This saw never idled right since a new piston( approx one year ago). Ran sufficiently at top end,although rich.I finally installed the 86-578-1 nozzle today.Now it idles nice when full temp, doesn't sound like its starving,and no longer hunting at idle.It is adjusting like any other carb.1 3/4 turns at idle and around 1 7/8 turns (prob too rich) at high setting.Finally feel I can use this saw instead of dicking around with it.

 

[K-techcowboy]

Swap out the main nozzle with one from a hda 191/199 no more issues with the bypass.

Then it tunes just fine.

They tune just fine anyway

 

[K-techcowboy]

My neighbor is having some problems with his saw running properly. Trouble starting and then stalling. Told him to bring it over to see if I could help.
He had removed both limiter tabs and the deflector plate on the muffler and left the screen in. That's the only mods.
I removed what little fuel he had in the tank and added mine. I run 91 ethanol free all the time. I started adjusting the carb and started to run much better. Finally got it to idle and the throttle response was spot on. Adjusting the "H" in the cut revealed only 1-1/8 turns CCW from full CW. I found this to be strange. My Timberwolf "H" screw is out 3 full turns CCW with the same muffler mod.

Just wondering if anyone else has "H" 1-1/8 turns CCW on their Timberwolf with the muffler deflector plate removed.

Thanks

I'm at about 2 1/2 to 2 3/8 on mine here in Oklahoma

 

[K-techcowboy]

The carb on the 590 is a bit different than most saws, having the H 1/2 a turn out is not uncommon. In fact the saw will still run OK with the needle fully seated. If you're saw doesn't have any underlying problem, it will be running dog rich with the H turned out 3 full turns.

Mines at 2 3/8 and runs perfect. Most factory carb settings are at least 1 full to 1 1/2 turns out. Id be looking at your saw for a ❄ white plug cause anything less than 1 is lean as f