Echo 590 vs 620P

[Nutball]

I'm going to compare these two saws side by side, inside and out, stock cutting performance vs some other saws, then port them and re compare against some other saws.

Same muffler, except for the writing on it, different chain catches








Look closely


620 has a roomy mag clutch cover, the 590 has a plastic one.

 

[Nutball]

I wonder if they forgot a part? That's really soft foam, so I don't think it really dampens any vibration other than when the peg would normally touch the sides. 620 has it.



They seem to be going to the handle as a gas cap wrench on more of their saws. Even the box didn't know about the change.


Stihl sized nuts on the 620



Echo doesn't seem to put much consideration into omnidirectional oil pickup. The over length line and the cap retainer being in the way means it will run dry if you make felling cuts clutch side up.

 

[dahmer]

I’m in.

 

[Nutball]

The tab on the bar plate rubs the clutch a bit, but it will wear out that issue.



I like how the 24" bar that came with the 620p is pro quality unlike their laminated bars which seem to wear out fast.

 

[pavel408]

The tab on the bar plate rubs the clutch a bit, but it will wear out that issue.

This looks kinda strange to me. Is it possible to push the protrusion down and to the right (from the clutch)?

 

[huskyboy]

This looks kinda strange to me. Is it possible to push the protrusion down and to the right (from the clutch)?

Looks like a retainer for the brake band

 

[pavel408]

Ahh, makes sense, thanks for explanation.

 

[ammoaddict]

I’m in.

Me too

Sent from my Moto G (4) using Tapatalk

 

[RI Chevy]

Cool thread...

 

[TreeLife]

Interesting, cant wait to see the guts and the numbers.

 

[Nutball]

The air filter material is highly restrictive, but the large surface area of it makes it not very restrictive overall. I think I'll still convert at least half the filter to nylon mesh. Large surface area filters should be good in the sense that the airspeed through any one part is slow, hopefully so slow that gravity and inertia will prevent the saw dust from getting stuck in the filter, at least the heavier stuff.

 

[Nutball]

I will do the stock comparisons today, but will wait to post the video until I have the ported tests completed, so it can be all one video. It will be these vs all stock, well broken in Husqvarna 455, 359, & 372. Sorry, I have no Stihls available to compare. I'll try to make my Echo test bar, or at least the chain, fit them, but it might not. I'll get compression, squish, timing numbers and cylinder pics right after.

 

[JohnnyBlade]

OH YEAH!!!

 

[Duane(Pa)]

Eyes inn. Good thread!

 

[BK13]

620 has a roomy mag clutch cover, the 590 has a plastic one.
View attachment 204291

Just for gits and shiggles, will the 620 cover bolt up to the 590?

 

[Nutball]

It appears the clutch cover, clutch bell, and handle are all interchangeable. I did add the 590 clutch cover spikes as they don't come with the saw.

 

[cuinrearview]

Very nice thread.

 

[Nutball]

That took longer than expected. Stock testing complete. I was able to use the same chain on all saws, and saved the trenching cut for last, the chain seems fine though, but I'll sharpen it a little before the ported runs.

Based on feel alone: the 455 did better than I thought it would, and the 372 was the obvious winner, I could really lean on it. The 359 seemed to have tuning issues, mainly on the low speed.

They both needed some tuning from the start. The 590 was all lean, wanting to die during acceleration. The 620 had a rich enough idle for this cool weather, and screamed on the high end. I tuned them a bit without a tach. The 590 feels and sounds ported for torque, while the 620 was obviously a bit peakier. That alone could affect the cut times since Ash likes a really slow chain speed.

Both had 136psi hot according to my gauge. So I'll assume the 620 has a lower intake rather than a higher exhaust. I almost thought the 590 seized just before compression testing, but apparently I had the long plug attachment on stopping the piston

 

[dahmer]

. I almost thought the 590 seized just before compression testing

 

[Nutball]

1 year old Ash log, I started at the small end, it's not too much bigger at the big end, but may have gained an inch or two. I would say these are some really good cut times for stock saws, excellent actually, but I'm not cutting on the usual end on that log which is a little bigger, and I've had practice cutting that log. Normally I'd expect 22-30 seconds for these saws, 15 seconds for an aggressive chained 90cc.

70DL 3/8
Times:
455: 21.8, 20 Avg: 20.9
590: 17.8, 16.5, 18.5, 19.5, 19 Avg: 18.26 Seems to have slowed when I tuned it richer to where I like it. But, the log is getting bigger. Plug was grey after the first 3 cuts.
620: 16.2, 18.7, 18.8, 17.75, 19.3 Avg: 18.15 I wouldn't be surprised if the 620 has a little more power, but the extra cost mainly buys you more durability.
359: 17.8, 19.25, 19.3, 20.25 Avg: 19.15
372: 13.6, 14, 15.4 Avg: 14.33