Echo cs 590,600,620 porting/mod/build thread

[Red97]

Info?

https://www.google.com/url?sa=t&sou...FjAAegQIBRAB&usg=AOvVaw2rYimfamsi4kiSxZX-6yip

 

[T.Roller]

Very cool. Great work. I read the first few pages then skipped to the end and seen the castings your working on. Very awesome.

 

[longleaf]

Hoping to get this one to a few gtg yet this year.

I watched the build thread that saw is awesome. Like pourin noodles from bucket.

 

[longleaf]

Del builds a good saw. Never seen him talked about except by other people that have saws he did. It' fun with a 20 and really doesn' lose anything with a 24.View attachment 128574 View attachment 128575rocked the 7910 chain. Bucked the whole tree down with the 590 and 24.

I think with the long stroke running a 24-28" is where they show out the most.

 

[Red97]

I watched the build thread that saw is awesome. Like pourin noodles from bucket.

Thank you.

Going to try a few more things with the ports before I call it done.

Still a nice firewood saw as is.

 

[Nutball]

Look at the muffler. Start with the muffler. Do nothing but gut the muffler and see what happens. Then understand why it happened.

Then start looking at other areas for improving, specifically the intake tract.



There is way more to it than numbers and what numbers I would use.

Think of this saw as a diesel truck. You want it to beat a car with a small block. Capitalize on torque. It can pull a bigger gear.

I just test ran my 590 after doing a few mods. So far: base gasket delete, muffler mod, raised the exhaust about 1mm or so, and widened it to 65% & matched the muffler and gasket. I didn't do enough test cuts to rule out imperfect technique, but the muffler mod had about a 25% increase in cutting speed, then I modified it more to open it more while patching over a hole I initially made that made it pop really loudly. That muffler mod with the exhaust port mod, and a more aggressive chain cut a little slower than the muffler mod alone until I looked back at the MM only video and tried to match and improve on that technique. It then cut only about 5% faster, so I'd say I can't be too sure the gasket delete and enlarging the exhaust port did much if anything. So maybe it all lies with the compression and intake on the 590 in terms of getting more torque out of it? I wasn't going for a race saw, just improved torque and power. It would seem in that case that a muffler mod and likely compression are the biggest factors without modding the whole intake system.

 

[David Young]

I think based on recent experience the popping was from hitting the limiter. they are listed at 12.5-13500. when you first hit the throttle you will see that. after holding it wot it will limit to 11500. the saw I modded will hit that in the wood unless I load it heavy.

You can hear it in these vids at the beginning. I think the best fix is an unlimited coil

 

[Red97]

I think based on recent experience the popping was from hitting the limiter. they are listed at 12.5-13500. when you first hit the throttle you will see that. after holding it wot it will limit to 11500. the saw I modded will hit that in the wood unless I load it heavy.

You can hear it in these vids at the beginning. I think the best fix is an unlimited coil

You mod the carb?

 

[usmcbuckwild]

I think based on recent experience the popping was from hitting the limiter. they are listed at 12.5-13500. when you first hit the throttle you will see that. after holding it wot it will limit to 11500. the saw I modded will hit that in the wood unless I load it heavy.

You can hear it in these vids at the beginning. I think the best fix is an unlimited coil

I have chased my tail with an Echp CS800 i did. Pulls like freight train but would pop/crackle. It seems to me the limited coil kicks in/cuts out at lower rpm under load. The pop/crackle was unburned fuel. I can’t say for sure, but richening it up a touch helped a bit. Richening to stop the pop/crackle also made the saw a little sluggish.

 

[David Young]

You mod the carb?

No

 

[Red97]

No

All the ones I've done won't lean out much past 12k without the carb mod.

Limiter has been around 13.2-5

Ymmv

 

[David Young]

I’ll check it it thanks Joe

 

[huskihl]

All the ones I've done won't lean out much past 12k without the carb mod.

Limiter has been around 13.2-5

Ymmv

I’ll check it it thanks Joe

So it's governed like a 288?
David, that's maybe why you thought it was hitting the limiter while cutting. Also explains why the 4 stroking rpm isn't constant.

 

[David Young]

If I remember the main jet has a hole in the back. Making it a partially fixed main jet.

 

[Red97]

If I remember the main jet has a hole in the back. Making it a partially fixed main jet.

Yep, swap that puppy out with a solid one, and ya good to go.

Makes all the difference being able to fully tune them.

 

[huskihl]

Yep, swap that puppy out with a solid one, and ya good to go.

Makes all the difference being able to fully tune them.

Could it be JB Welded?

 

[Red97]

Could it be JB Welded?

Probably. But only takes a few min to pop it out and drive a new one in. Most other hda have the solid jet.

 

[huskihl]

Probably. But only takes a few min to pop it out and drive a new one in. Most other hda have the solid jet.

I see. Just wondering, in case a guy didn't have one laying around.

 

[usmcbuckwild]

I see. Just wondering, in case a guy didn't have one laying around.

Good thinking

 

[Battle Cross 2]

All the ones I've done won't lean out much past 12k without the carb mod.

Limiter has been around 13.2-5

Ymmv

That might explain why the saw @dahmer has seems like it turns more RPM then the one del did for me. Guess I should look into modding the carb.