ECHO CS-7301

[Franny K]

This is true to US EPA system but there are no exceptions or credits for EU market.
Only Stage 5 certified units are allowed since January 2019.
7310 passes that limit with some margin.

Here’s an entire EPA list with their out-of-box dyno/testing/emissions results:
https://www.epa.gov/sites/production/files/2020-01/small-nonroad-spark-ignition-2011-present.xlsx

I could not get it to open at first. Not sure if I opened your specific link or a similar one I searched. It must be an excel file. I have a libe program that will open it but can not figure out how to freeze panes. For over half an hour of effort I found I only found cc useful missed model number but the Husqvarna has electronic carb.

Echo 73.5cc row 1076 thru 1079 power of 3.2 @9,300 power of 4 @10,000 (column y and z) column at is co result 397, 409 at 9,300 and 317,320 at 10,000 Column bb is HC-NOX cert level which I chose to compare 61 at 9.300 and 58 at 10,000


Husqvarna 70.6cc rows 1313 and 1314 power of 3.71@9,300 and 4.18@9,900 CO of 245@9,300 and [email protected] The HC-NOX cert level if that is the right thing to zero in on is 56 and 55.

I will let someone else pick a comparable Stihl.

Sure is easier to look at the clean air index tag that is often tied to the rear handle. It appears somewhat more polluting, somewhat larger displacement and somewhat less power than the Husqvarna comparable.

 

[Piston Skirt]

I could not get it to open at first. Not sure if I opened your specific link or a similar one I searched. It must be an excel file. I have a libe program that will open it but can not figure out how to freeze panes. For over half an hour of effort I found I only found cc useful missed model number but the Husqvarna has electronic carb.

Echo 73.5cc row 1076 thru 1079 power of 3.2 @9,300 power of 4 @10,000 (column y and z) column at is co result 397, 409 at 9,300 and 317,320 at 10,000 Column bb is HC-NOX cert level which I chose to compare 61 at 9.300 and 58 at 10,000


Husqvarna 70.6cc rows 1313 and 1314 power of 3.71@9,300 and 4.18@9,900 CO of 245@9,300 and [email protected] The HC-NOX cert level if that is the right thing to zero in on is 56 and 55.

I will let someone else pick a comparable Stihl.

Sure is easier to look at the clean air index tag that is often tied to the rear handle. It appears somewhat more polluting, somewhat larger displacement and somewhat less power than the Husqvarna comparable.

Line with 3.2kW is a cut-off saw, you may disregard that one in this topic.
All recent engines go under the most recent limit. Engines like “reintroduced” 372XP use banking points (therefore in US under EPA it will be sold, in Europe - no).

 

[Andyshine77]

Not only EPA but this is another "global" engine, as every continent has slightly different limits.
15 years ago Husky was very loud in their tech trainings that no conventional engine would be able to pass anything without strato (which they bought back then with Zenoah) or expensive catalyst.
Guess what, with some hard work and charge swirl control it was and still is doable. Sure, it takes more ports and complicated timing, but it's still doable.

As for other manufacturers - once your engineers get experience how to replace unburnt fuel droplets in exhaust with clean air, why waste the time&money and re-educate them on swirl control?

Not that simple. As mentioned above companies can work around regulations with credits, units sold and so on. A lot of Echo's small engines do have cats in the muffler, I just had a small blower with a burned up piston caused by the heat from the cat. So those really clean burning engines off set the not so clean engines.

 

[Piston Skirt]

Not that simple. As mentioned above companies can work around regulations with credits, units sold and so on. A lot of Echo's small engines do have cats in the muffler, I just had a small blower with a burned up piston caused by the heat from the cat. So those really clean burning engines off set the not so clean engines.

Once again, there are the same engines imported to Europe which has zero flexibility above the limits. And the limits are very close to those of EPA.
There are different limits for below and above 50ccs (note where are all “49,9” gone from all manufacturers )
And of course the small 20-30cc engines give a lot of credits for manufacturers in US - all the 880’s, 372’s, 620’s etc are there just because of that.

 

[Franny K]

Line with 3.2kW is a cut-off saw, you may disregard that one in this topic.
All recent engines go under the most recent limit. Engines like “reintroduced” 372XP use banking points (therefore in US under EPA it will be sold, in Europe - no).

Maybe the 9300 rpm Husqvarna one is a demo saw as well as it has a different engine number code.

 

[Andyshine77]

Once again, there are the same engines imported to Europe which has zero flexibility above the limits. And the limits are very close to those of EPA.
There are different limits for below and above 50ccs (note where are all “49,9” gone from all manufacturers )
And of course the small 20-30cc engines give a lot of credits for manufacturers in US - all the 880’s, 372’s, 620’s etc are there just because of that.

Is the 7310 CARB compliant? Echo did a great job with the 7310 no matter how you look at it.

 

[Piston Skirt]

Maybe the 9300 rpm Husqvarna one is a demo saw as well as it has a different engine number code.

That’s 565.

 

[Paul Silvestri]

Exactly

 

[Piston Skirt]

Is the 7310 CARB compliant? Echo did a great job with the 7310 no matter how you look at it.

Probably. As I’m European for me the Stage-5 matters.
Just a few years until next stage though

 

[RedneckChainsawRepair]

Stock to stock runs by Joe. 572 462 7310 7910 500

Here is a dyno run of 5 new 70cc-79cc all stock.

The 7900 had a 7910 topend on a 6421 with 64 coil but also with CAT muffler

 

[Red97]

7310
Vs

Cs8000

2 runs of each saw shown. Runs done back to back.

Cs1200 Was 7hp,7ftlb stock.

 

[ElevatorGuy]

View attachment 872597

7310
Vs

Cs8000

2 runs of each saw shown. Runs done back to back.

Cs1200 Was 7hp,7ftlb stock.

Are you happy with the 7310? From your charts it looks like the 462 is really the saw in that class.

 

[RedneckChainsawRepair]

View attachment 872597

7310
Vs

Cs8000

2 runs of each saw shown. Runs done back to back.

Cs1200 Was 7hp,7ftlb stock.

Well that settles that.

 

[Red97]

Are you happy with the 7310? From your charts it looks like the 462 is really the saw in that class.

Not run any of them really. All had less than 4 tanks.

The 462 was making the power for sure.

 

[Andyshine77]

So the 800 is way down on HP, but as expected more bottom end. So the 7310 should cut circles around the 800.

 

[Paul Silvestri]

And the

So the 800 is way down on HP, but as expected more bottom end. So the 7310 should cut circles around the 800.

And the 7310 looks much better also! That counts for something right!?

 

[Andyshine77]

Are you happy with the 7310? From your charts it looks like the 462 is really the saw in that class.

I would say so. Even the wood dyno agrees.



I like the 7310 a lot, but it's heavy for the power. I put the 7310 ahead of the 572 in every respect accept out of the box power, and it feels like a cinder block.

 

[Andyshine77]

And the

And the 7310 looks much better also! That counts for something right!?

You bet![emoji1]

 

[ElevatorGuy]

I would say so. Even the wood dyno agrees.



I like the 7310 a lot, but it's heavy for the power. I put the 7310 ahead of the 572 in every respect accept out of the box power, and it feels like a cinder block.

Heavy seems like an echo thing. I love my 590 and the price was hard to beat at half of an ms362. The 7310 is attractive at $800ish but I think for a few hundred more I’ll go with the 462. I’d probably sell my 590 to offset the price some. I don’t see myself keeping the 590 with a new 70cc saw that makes more power and is around the same weight.

 

[Paul Silvestri]

You bet![emoji1]

So stock for stock what would you buy if they were the same money. And given attention to antivibe management? I’ve watched all your videos on both of the saws and it seems like you love them both. I’m in the market for one or the other I’m just curious which way to go.