Echo cs400 L and H setting after muffler mod

[amhst56]

just got done with mm and carb mod and wanted to know how many turns u guys had on the l and h screws after u tuned it.

i read about 10 to 15 articles on this site. they are all about doing the mod and no mention of where anyone ended up at with the jets after they were done. only one guy said to start 3 1/2 out and go from there.

before mod im not sure on low, but high was 3 1/2.
after mod, im at 1 1/2 turns on low and 3 on high.

seems odd to me that i would lose 1/2 turn after mod, but i could have set it rich? didnt know how to adjust for 4 stroking until i did the mod though.

and since im new to adjusting to 4 stroking, just want to make sure what im hearing is 4 stroking and not the rev limiter kicking in.

so, anyone that did this mod, please let me and all the future mm people know what u have yours set at so we dont blow up our saws.

just so u know what i did (seems like people have minor differences).
i took out cat, only cut the 2 little cross members for the exhaust exit, and opened up the lower portion of the deflrector.
with doing that at 55 degress, L is 1 1/2 and H is 3 turns.

thanks in advance for the help, its much appreciated!

 

[Full Chisel]

Tune it very rich...3 1/2 turns out on the H sounds about right. Then lean it out slowly until it cleans up in the cut. Don't tune by ear at WOT...the limited ignition makes it tough.

 

[mountainlake]

Same as above, only start out at 4 1/2 turn out on the high just to make sure, at 3 turns out you could very well be bumping into the rev limiter. These saws need to be tuned in the cut. Steve

 

[o8f150]

i dont know exactly i just richen it up at least 1 full turn from factory and then start leaning it out,, been several of them i only had to go 1/4 turn richer

 

[zogger]

You should need more fuel on the H with the muffler mod, so if you started at 3.5 stock, try around 1/4 turn more CCW/richer for a start.

 

[amhst56]

thx for all the replys,

i read a lot of post and watched a few videos on tuning.
i did tune in the cut twice. i started at 4 turns both times and kept turning it down 1/4 turn until it sounded smooth in the cut.

first time i ended up at 3 1/4 and second sounded best at 3.
any higher, and it doesnt sound smooth in the cut.

any ideas why mine might be different than everyone elses or have any ideas of what else to try?

thanks!

 

[amhst56]

if i ran my saw for a few cuts at full throttle and turned it off while still in full throttle cut. would the sparkplug show if im lean?

or how do i adjust the high with a tachometer if i bought one? seems worth it if it saves my saw.

thanks again

 

[Full Chisel]

Tuning in wood is better than reading the plug, although if you are getting a chocolate brown you should be good.

A tach will not work to tune a rev limited saw...

 

[Cliff R]

Completely impossible to read spark plugs for tuning.

Start out a tad too rich as mentioned, then sneak up on the ideal setting by leaning it up slightly and making a few cuts. Many Echo saws use timing retard modules so they will act like a rev-limited at high rpm/no load.

They still tune like any other saw, and you will notice loss of power and some "four stroking" when it's too rich at full load.

It's also important to have the saw up to full temperature, and set the "L" screw first. Go to the highest idle speed then slightly rich with it until you just hear the engine change pitch. Do some quick hits of the throttle and make sure it doesn't stumble and returns easily to idle speed.

Then set the "H" speed screw doing some heavy cuts, it's really not that fussy, and always er just a tad rich vs a tad lean, this increases oil delivery, reduces no load rpms, and decreases EGT's......the saw will love you for it......Cliff

 

[stihl041avhog]

Would these carb setting apply to an cs-310? I did about the same to my muffler and having a tough time of getting it to run right, bogs on full throttle. I didn't count the turns on the carb screws before i took the caps off.

 

[o8f150]

Would these carb setting apply to an cs-310? I did about the same to my muffler and having a tough time of getting it to run right, bogs on full throttle. I didn't count the turns on the carb screws before i took the caps off.

yep the same way,,, here is the 310 i did and its my truck saw,, i have it a tad rich but thats the way i like them

 

[stihl041avhog]

yep the same way,,, here is the 310 i did and its my truck saw,, i have it a tad rich but thats the way i like them

Thanks will try later tonight. pos echo's lol

 

[amhst56]

yep the same way,,, here is the 310 i did and its my truck saw,, i have it a tad rich but thats the way i like them

the first part of video sounded rich to me in the cut, after u modded it it sounded clean in the cut.
could u do me a big favor and check how many turns u have the low and high at in your cs400?

im gonna try it again in a few minutes, it starts, idles and picks up great so i think i have the low set right, going to start out at 5 turns and go down from there to be sure.
im thinkin it should smoke or stall being that right?

also, im reading a few articles about tuning a rev limited saw with a tach. if i richen the high until right before rev limit, will it be to rich all around or will it give it more power in the cut and save it out of the cut and over reving in the small stuff?

thanks again all

 

[amhst56]

https://www.google.com/url?sa=t&sou...NJU4BBSZ15VnCC3kA&sig2=-Cdl_aihJX18w-FXUxez3w

hopefully the link works.
i did a quick video of a couple different high settings.
i could here a little 4 stroking on 3 1/2 turns i think.

i tuned in a big oak, the outer 1/2 was rotted, but the rest was solid. not sure if it was to big of a piece or to hard?

at 3 1/2 as soon as was done with the cut, i let off from full throttle and it alsmost stalls. it did stall at 3 3/4. not sure if this is the high or low that needs adjusting?

let me know what u guys think
thanks

 

[amhst56]

just had a thought
i run 87 oct with alittle stable and ethonal shield in it, could that be why 3 1/4 sounds best to me?

if i get 89 or 91, would that make it need more fuel?
thanks again

 

[Fishnuts2]

I think you're getting closer with the tune @ 3 turns, but it seems that you've got a dull chain. That might be why it is getting hot and you shouldn't have to force it to cut like that.
You'll like that 400 after you get er dialed in.


Sent from my iPhone using Tapatalk

 

[amhst56]

I think you're getting closer with the tune @ 3 turns, but it seems that you've got a dull chain. That might be why it is getting hot and you shouldn't have to force it to cut like that.
You'll like that 400 after you get er dialed in.


Sent from my iPhone using Tapatalk

thx fishnuts,
im thinking the same thing, but everyone here that has done the mm has always richened it up. if i was at 3, thats 1/2 turn lean than stock.

i will put a new chain on it and cut again with another video.

should i be in the bigest hardest stuff i will be cutting?
or like medium size and hardness?
thx

 

[stubnail67]

chain sounds a lil tight .... is your oiler all the way up?you can adjust the low for throttle and some idle....3 turns is to lean in my opinion on the high.... after a muffler mod....try a new new chain and maybe not lean on it so much she is only 40 cc LOL .....keep playing with it you will find the sweet spot...... i think 3 turns is to lean was the muffler smoking after you shut it off? also rev it not in the log then put it in wood for a few secs with medium weight /pressure then lift it up a lil a few times so we can hear if its four stroking....thats how i check my self..... good luck .....

 

[amhst56]

chain sounds a lil tight .... is your oiler all the way up?you can adjust the low for throttle and some idle....3 turns is to lean in my opinion on the high.... after a muffler mod....try a new new chain and maybe not lean on it so much she is only 40 cc LOL .....keep playing with it you will find the sweet spot...... i think 3 turns is to lean was the muffler smoking after you shut it off? also rev it not in the log then put it in wood for a few secs with medium weight /pressure then lift it up a lil a few times so we can hear if its four stroking....thats how i check my self..... good luck .....

thx stub
i will put a brand new chain on it and turn the oiler up and then take a new video. probably in a day or 2, been workin 16hr days.

and the muffler wasnt smokin after i was done, but i could tell it was hotter than normal.

 

[amhst56]

check it out and let me know. I still think around 3 1/4 is good, but don't know if im hitting rev limit or 4stroking.

whats your opinion?