New Saw - First Time Modding

[Kustrud]

Hey guys, so I read through everything I could to wake my new saw up a bit but am having trouble tuning it. I've watched every video I can and I get the gist of it but am having issues and dont want to mess it up.

Echo 400 cs 18" bar

I modded the muffler by gutting the cat and opening the front up a bit.

I removed the limiter caps, but they were a PAIN to get uot and had no idea where they were set once I finally got the caps out. So I screwed them all the way in to start. Opened the L side 1 1/2 turns and the high side 2 1/2 turns and fired it up, idles really high and didnt seem right so I shut it down right away. So now I am back to having them both screwed in all the way and am here for some help to get this thing to run right now. How should I start? Any ideas for "starting points?"

 

[cuinrearview]

One turn out each

 

[Kustrud]

I'll try that and report back, thanks!

 

[Kustrud]

Alright, one turn out each = starts and then immediately dies. If I choke it - starts and revs up on it's own.

 

[ATH]

Scroll down and see the chainsaw section of the forum. You'll get more info there.

 

[Kustrud]

Are you saying I should post there instead? I have read and watched everything I can think of and find. I'm simply looking for specific instructions here.

Also, i just removed the muffler again and it seems "oil wet" - I'm guessing that's a sing I had it too rich at some point when trying this??

Again, started over - and my results with both L and H one turn out each are posted above. Need help.

 

[ATH]

Yes...you should post in chainsaw section. That is where you will get the best answers to chainsaw questions. Not that you are going to get bad info in 101...just expect more info down in chainsaws.

 

[Mustang71]

I always turn the low 1 1/2 to 2 turns out and turn it in until it idles good. I turn the high about 3 turns out and turn it in until it sounds right. The sound takes some time to get used to. The whole idea is to not lean it out to much on on the high end. You are better off having it way to rich when you start to tune it then having it way to lean and making it scream with no oil.

 

[Kustrud]

I always turn the low 1 1/2 to 2 turns out and turn it in until it idles good. I turn the high about 3 turns out and turn it in until it sounds right. The sound takes some time to get used to. The whole idea is to not lean it out to much on on the high end. You are better off having it way to rich when you start to tune it then having it way to lean and making it scream with no oil.

Ok thanks! How would I know if the low side is too rich? Would it bog after hitting the throttle off idle if the low side was too rich?

 

[Mustang71]

I turn it in until I have good throttle response. If it dies then it's to lean and turn it back out a bit. Once it's warmed up it should start first pull if it's adjusted right. You may need to adjust the t screw to stop the chain from spinning at idle.

 

[Jim Timber]

When I modded my 352 it was pretty easy to tune. I did the same in that I removed the cat and cleaned up the outlet but I don't remember to what extent. I don't know if I still have those pics on photobucket or not, but if you search my posts from 2012 or so you might find it.

I found that while that saw will rev to 16K now, it doesn't have any torque when set that lean. It runs much better in the wood when the max no load speed is set to 11K or whatever the manual says is max. It still loads down to 9Krpm in oak, but she pulls a lot better than when it was stock.


As far as tuning goes, you need to get it to stay running on the fat side of things and then let it warm up. From there you can dial it in, but you need to make your adjustments while the saw is running for them to be any good. So it's gotta be warm for your idle, and then it's gotta be under load for your high side. If you tune it for max rpm no-load, and then stick it in a heavy cut it'll go lean and roast itself. You want max rpm in the cut, and you can do that by ear. I got a tach because I was curious what my rpms were, not because it's needed to tune saws.

 

[Mustang71]

I always read you wanted it to fourstroke with no load then clear up when it hits the wood. Atleast that's what I read here when I rebuilt my ms290. That would put it rich with no load and just right with load. Sort of the same thing?

 

[Jim Timber]

You tune for max power, which is highest rpm under load. I always fatten my mix from there just to run the engine a little cooler for good measure. The burbling is hard to hear with some saws, but most people can discern a change in pitch when you hit the peak rpm.

Tuning to the burble (four stroking) ended up being really rich for me. Maybe it's just my screwed up hearing?

 

[Mustang71]

Yea idk the 290 did great with the 49mm kit fourstroked then hit the oak buried the 20 inch bar and never changed tone after that. That was the hardest one to hear the four stroking. My poulans that got muffler mods were easy to hear it. I never messed with the husky it's a wide open muffler from the factory.

How do u tune it in the wood that sounds hard to hold the saw in the wood and turn the screw. Also do u always use the same wood? Wouldn't that effect the rpm if it's green or dry or oak or maple or what not?

 

[Jim Timber]

I just get a chunk of oak and tune it with one hand on the saw and one on the screw driver. Pretty easy once you get a little kerf going for the bar to ride in. You don't need the same load every time, just enough to make the saw work. Bigger saws need bigger logs. When you think you have it dialed in, cut some cookies and see how you like it. Try some changes and see how it responds.

Low idle shouldn't need much if any tweaking when you get it set right, so you're only messing with one jet. Of course you want to let it cool down and restart it later to make sure it's not too cold blooded.

 

[Mustang71]

Sounds like a good way to tune a saw especially if you don't know what exactly you are trying to accomplish when tuning.

 

[Jim Timber]

I'm certainly not a pro tuner or anything, but I get good results and haven't roasted a piston yet.