As a stock saw.
Once ported they have a hard time leaning out enough. That is the reason for the nozzle swap.
Echo 590 Timberwolf "H" setting
- Thread starter hatfield
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Once ported they have a hard time leaning out enough. That is the reason for the nozzle swap.
So, if you had the high side a bit rich would it cause erratic idling when going from wide open back to idle? I'm talking about a stock saw, no mods.
They tune like ****, but are tuneable.
about 2 turns out on low
about 3/4 turn out on high
That's mine, give or take a 1/4 turn.
about 2 turns out on low
about 3/4 turn out on high
That's mine, give or take a 1/4 turn.
That's the stock FSM settings L mixture needle : 2, H mixture needle : 3/4
Well there you go. I pulled the caps without checking the settings. Then I tuned it and possibly ended up right where I started..lol. It's near 30 below C here today, I fattened it up a tad. It was a hair lean all over.
K-techcowboy
N.A.O.T Racing
Take the limiters off. No lack of range then.
So nice to be able to scream this saw with the new valve,lol.Easy to do valve.Mine (590)still kinda drifts a bit up and down after pulling out of the cut at idle,throttle hangs just a little for several seconds.When richened up a hair, will eventually stall the rpms.Must have an air leak (slightly) somewhere,this after new seals and new piston.Was a broken saw {bad piston) purchase.Cuts well,good power, just isnt perfect yet.I love a tuned saw that immediately returns to idle and idles til the cows return home.
K-techcowboy
N.A.O.T Racing
There's wasn't mention by him his was ported just muffler mod. This tuning trouble is the only reason I haven't touched my head yet. Seems like more trouble then its worth when you can just buy a bigger saw or a 620 jug and carb
Wanted to jump in here and say thanks to everyone for the info on swapping the nozzle. I just got a used but great condition 590 that was all kinds of funky as far as carb issues. TLDR; nozzle swap got her sorted out, and easy fix for about $8.
Long version: someone had been monkeying around in there. Carb bolts were stripped, L had been reset and recapped so lean you couldn't get it to idle, and when that was fixed (remove said caps), idle was all over the place and then eventually would die.
Check valve operation of the original was completely gone, I could blow air through either way. The disk was deformed, so I'm guessing someone either blasted it with compressed air or enough carb cleaner to deform it (or both).
I also saw a video where one guy used JBWeld on the stock nozzle to seal it up and allow full use of the H adjustment. Honestly I think I'd rather either pound it shut (brass is soft-ish) or put a small screw in there, assuming the check valve action was still functional.
I debated going the 203 swap route, but for $8 it was worth rolling the dice. That said, TinMan has a good video comparing the carb throat sizes and 203 was definitely opened up more.
Also, for anyone who has stripped carb bolts and wants an easy fix: I got #12 x 2 in. Phillips Pan Head Stainless Steel Sheet Metal Screws from HD that are just a hair bigger OD than the original bolts. They bit in the plastic housing like they were meant to be there, but still fit through all the original holes for the carb and breather shroud. I'd say it's stronger now than the originals. The heads are a touch big (wide) and I might chuck them and take a little bit off, but everything still fit together without issue.
Last note (already covered in some manner in this thread): for anyone else doing the nozzle swap, make sure you back out that H needle a couple full turns and then tune it as needed from there. If you leave it at it's stock setting you'll burn it up since it's not automatically pulling fuel through the nozzle like the original was.
Muffler, you're about to meet my dremel.
Long version: someone had been monkeying around in there. Carb bolts were stripped, L had been reset and recapped so lean you couldn't get it to idle, and when that was fixed (remove said caps), idle was all over the place and then eventually would die.
Check valve operation of the original was completely gone, I could blow air through either way. The disk was deformed, so I'm guessing someone either blasted it with compressed air or enough carb cleaner to deform it (or both).
I also saw a video where one guy used JBWeld on the stock nozzle to seal it up and allow full use of the H adjustment. Honestly I think I'd rather either pound it shut (brass is soft-ish) or put a small screw in there, assuming the check valve action was still functional.
I debated going the 203 swap route, but for $8 it was worth rolling the dice. That said, TinMan has a good video comparing the carb throat sizes and 203 was definitely opened up more.
Also, for anyone who has stripped carb bolts and wants an easy fix: I got #12 x 2 in. Phillips Pan Head Stainless Steel Sheet Metal Screws from HD that are just a hair bigger OD than the original bolts. They bit in the plastic housing like they were meant to be there, but still fit through all the original holes for the carb and breather shroud. I'd say it's stronger now than the originals. The heads are a touch big (wide) and I might chuck them and take a little bit off, but everything still fit together without issue.
Last note (already covered in some manner in this thread): for anyone else doing the nozzle swap, make sure you back out that H needle a couple full turns and then tune it as needed from there. If you leave it at it's stock setting you'll burn it up since it's not automatically pulling fuel through the nozzle like the original was.
Muffler, you're about to meet my dremel.
yup..thanks.Wanted to jump in here and say thanks to everyone for the info on swapping the nozzle. I just got a used but great condition 590 that was all kinds of funky as far as carb issues. TLDR; nozzle swap got her sorted out, and easy fix for about $8.
Long version: someone had been monkeying around in there. Carb bolts were stripped, L had been reset and recapped so lean you couldn't get it to idle, and when that was fixed (remove said caps), idle was all over the place and then eventually would die.
Check valve operation of the original was completely gone, I could blow air through either way. The disk was deformed, so I'm guessing someone either blasted it with compressed air or enough carb cleaner to deform it (or both).
I also saw a video where one guy used JBWeld on the stock nozzle to seal it up and allow full use of the H adjustment. Honestly I think I'd rather either pound it shut (brass is soft-ish) or put a small screw in there, assuming the check valve action was still functional.
I debated going the 203 swap route, but for $8 it was worth rolling the dice. That said, TinMan has a good video comparing the carb throat sizes and 203 was definitely opened up more.
Also, for anyone who has stripped carb bolts and wants an easy fix: I got #12 x 2 in. Phillips Pan Head Stainless Steel Sheet Metal Screws from HD that are just a hair bigger OD than the original bolts. They bit in the plastic housing like they were meant to be there, but still fit through all the original holes for the carb and breather shroud. I'd say it's stronger now than the originals. The heads are a touch big (wide) and I might chuck them and take a little bit off, but everything still fit together without issue.
Last note (already covered in some manner in this thread): for anyone else doing the nozzle swap, make sure you back out that H needle a couple full turns and then tune it as needed from there. If you leave it at it's stock setting you'll burn it up since it's not automatically pulling fuel through the nozzle like the original was.
Muffler, you're about to meet my dremel.
I am assuming you went with
Walbro OEM 86-578-1 replacement Nozzle?
my 590 also is a PIA to adjust. I did a muffler mod...and it seems a little better...but its still real rich.
Im not too kean on jb weld in there...but I see a few guys have done it.
I also think I could pean it closed...or pretty close to closed.
Thanks in advance.
Yah 86-578-1, adjusts as expected now. If the check valve had been functional I think I would have just used a punch and tried to close up that hole. Just had it out last weekend post muffler mod cutting up a 20"+ blow down tree.
Was not disappointed in the least... until I hit something and started spittin' dust.
I just ordered that jet. I hammered out the original. what a Stupid idea.....ive seen more stupid, but this has frustrated 1000s of timberwolf owners I am sure. my saw never really ran great. see How this goes.
couldnt hammer that hole closed....and I didnt want to glue anything...
couldnt hammer that hole closed....and I didnt want to glue anything...
Finally got mine returning to idle properly without hunting rpms. Resealed the base of cylinder with 1184 as it must have been sucking air from there. Good power for what it is.
