Echo 490 to ported 4910…to cs-5484

[Duane(Pa)]

Any way you can try a different coil? Is this the 490 coil or 4910?
Maybe try higher octane fuel?

 

[Red97]

An actual 4910 coil may work. Not sure if it will work with the 490 flywheel or not.

 

[drf256]

I’m asking about the Compression because my 361’s actually require a timing retard to not pop.

Other people, that dont have the same compression as me, actually advance the timing.

 

[Ketchup]

I’m asking about the Compression because my 361’s actually require a timing retard to not pop.

Other people, that dont have the same compression as me, actually advance the timing.

That’s interesting. No, I haven’t pulled compression. I doubt it’s super high. I only took 0.025” out of the band (squish is 0.022”) and there’s no air up here. But I’ll check it. I’ll also order a new tach. Mine fell out of a tree and isn’t trustworthy.

It could be my imagination, but the saw seems to run better cold. The first cut hits a higher rpm and is smoother. But by the bottom of the first cookie it’s slowed down a bit, doesn’t recover rpm as fast when I back off, and pops intermittently. I’ll dig into it this afternoon.

 

[Dolkitafreak]

An actual 4910 coil may work. Not sure if it will work with the 490 flywheel or not.

I believe it will.

 

[Ketchup]

FFS…
The 500sx mesh filter is complete garbage.


New ring ordered, jug okay…


Does look fat.

 

[Red97]

I'll be testing this one in the next couple weeks.

Cartridge style filter and 3d printed cover.

 

[Ketchup]

I'll be testing this one in the next couple weeks.

Cartridge style filter and 3d printed cover.
View attachment 371263

I saw those. I may be doing the same.

 

[huskihl]

I'll be testing this one in the next couple weeks.

Cartridge style filter and 3d printed cover.
View attachment 371263

Something new from Nick?

 

[Red97]

Something new from Nick?

No, it was on eBay. Guy reached out on youtube.

 

[Ketchup]

Something new from Nick?

Nick has one in the works as well.

 

[Ketchup]

Here’s a bit of fun. Turns out the trigger travel was just maxing out, the linkage wasn’t bending enough to matter. So I extended the trigger side with an old 9mm cartridge. Butterfly opens completely now.

 

[Red97]

Here’s a bit of fun. Turns out the trigger travel was just maxing out, the linkage wasn’t bending enough to matter. So I extended the trigger side with an old 9mm cartridge. Butterfly opens completely now.
View attachment 371286
View attachment 371285

That will do it

 

[drf256]

I had to make an AF. I was jealous of your 500SX airfilter until I wasn’t.


I don’t understand your popping with only 130 psi of static compression. I would retard the timing a few degrees ano see if it goes away. Shouldn’t be too hard to do.

Has anyone put a timing light on this model to see where it is stock?

 

[thedude74]

Here's the CS500p technical data....same coil/flywheel part numbers as the cs490

Looks like 35* BTDC @10K RPM

Also has resistance specs for primary and secondary windings...Probably worth checking as well.

 

[Red97]

Curious to see how it acts with true full throttle.

 

[Ketchup]

Here's the CS500p technical data....same coil/flywheel part numbers as the cs490

Looks like 35* BTDC @10K RPM

Also has resistance specs for primary and secondary windings...Probably worth checking as well.
View attachment 371314

Great info there. 35 degrees seems a bit aggressive. Are you able to find the same technical data for 501p? I tried a google search, but only got sales pages and operators manuals.

I kind of feel like I have had a coil issue from day one.

As far as compression, my numbers are always low. 125 is pretty normal for a stock saw up here. But this saw should be 150-160 here. I have to assume the fines wrecked this ring. Still, I want more compression than 160. That means I will probably have to pull the jug and re-machine. I should have been more aggressive initially. Low compression is not a new problem here.

 

[pavel408]

Great info there. 35 degrees seems a bit aggressive. Are you able to find the same technical data for 501p?

For CS-501SX should be the same, I suppose.

 

[Red97]

Where did the ports end up?

 

[Ketchup]

For CS-501SX should be the same, I suppose.

View attachment 371328

Thanks! Interesting that they dialed back the timing, especially for the heated version. I wish the heated red ones were available in the US.

Where did the ports end up?

Still sitting at 78-105-124/128. I was already inclined to even out the transfers so I’ll do that while I have it apart. Undecided on the lowers. I’m tempted to blend the primary.