Echo 620p upgrades

[btmonnat]

Just bought an echo 620p after roughly 40 years of running about every model husky has had except the biggest model. Not wanting the expensive autotunes I decided to save roughly 300$ and try something else. I do still have my 346xp that I muffler modded and got rid of the limiter caps. That alone really woke that saw up. 13years and still runs awesome. Just wondering if my 620p would respond the same by just opening up the bottom side of the muffler deflecter and getting rid of the limiting caps. Really don't want to do any more. Thoughts or experiences would be greatly appreciated.

 

[mountainlake]

Echo saws need both as most come tuned lean with a clogged up muff thanks to the EPA. Steve

 

[Cliff R]

+2

That's all the CS-590/600P/620P's need is the limiter caps removed and opening up the deflector on the muffler to let them breath a tad better. I own all three here and they see a LOT of use. They are also really easy to work on. You can have the carb off one in less time that it took me to type this and it only takes seconds to remove the limiter caps, grind the "stops" off and push them back in place for full control with the "L" and "H" screws.....

 

[btmonnat]

+2

That's all the CS-590/600P/620P's need is the limiter caps removed and opening up the deflector on the muffler to let them breath a tad better. I own all three here and they see a LOT of use. They are also really easy to work on. You can have the carb off one in less time that it took me to type this and it only takes seconds to remove the limiter caps, grind the "stops" off and push them back in place for full control with the "L" and "H" screws.....
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That's great, just what I needed to see and hear. I ordered a dremel tool this morning, should work good for this and expect to have it next week. Might just wait to do anything until I run a few tanks through it to make sure there are no issues that need warranty work done.

 

[ballisticdoughnut]

I’ve done pretty much everything besides port work on my 600P. Muffler mod and carb adjust is a must, really all you need to do on a 620 since it’s the hod rod version of the 590.

 

[Cliff R]

I would NOT put the first minute on the saw until you modify the limiter caps for full control with the "L" and "H" screws. That's what I do to every single Echo saw that I've purchased for my own line-up. Some aren't lean enough to "smoke" a P/C but some are lean enough to do some damage so why take the chance?

For the record the CS-620P and PW's I've had here have never been lean enough to be alarming, but for sure some models will BARELY run until full warmed up and even then they are so lean they hesitate and spike right up against the rev limiter or timing retard module at full throttle. This often fools the novice tuner into thinking they are putting down plenty of fuel at full load and the best way I know to damage the P/C. So why take the chance?......

 

[Cliff R]

I'll add here for any CS-7310 owners that the carb on those saws is NOT nearly as easy to modify as the ones in the pics above. The mixture screws themselves have really small heads on them and the limiters are a LOT more difficult to remove......

 

[toppers]

7310 carb screws are the worst I've seen, agreed. Gotta remove it and put the carb in a vice to have a chance at working on it.

 

[Cliff R]

Yep, new learning curve there for me and glad I treaded softly into the first one I did as it could have been easily FUBAR'D.......

 

[btmonnat]

I would NOT put the first minute on the saw until you modify the limiter caps for full control with the "L" and "H" screws. That's what I do to every single Echo saw that I've purchased for my own line-up. Some aren't lean enough to "smoke" a P/C but some are lean enough to do some damage so why take the chance?

For the record the CS-620P and PW's I've had here have never been lean enough to be alarming, but for sure some models will BARELY run until full warmed up and even then they are so lean they hesitate and spike right up against the rev limiter or timing retard module at full throttle. This often fools the novice tuner into thinking they are putting down plenty of fuel at full load and the best way I know to damage the P/C. So why take the chance?......

Pulling the limiter caps tomorrow, they did make some carb adjustments before I left the shop.

 

[btmonnat]

Only other question I have is: I have access to a rpm monitor and was wondering what a safe no load rpm would be for that saw. I do have somewhat of an idea but would like some confirmation from someone with experience with these.

 

[Cliff R]

I don't use one here and from what I can tell the CS-620P's are not limited. There really isn't a "safe no load RPM" for any saw. Far more important is to make sure that it is four-stroking nicely but cleans up and pulls hard in the cut as soon as you put load on it. During the cut, if you remove the load it should start four stroking nicely once again.

When tuning saws it is ALWAYS better to "sneak" up on the perfect tune by starting out rich enough it's four stroking pretty heavy and a tad down on power. Richen it up with each cut till it starts cleaning up nicely in the cut and making best power. If yoiu aren't exactly sure where that is ALWAYS er a tad rich vs a tad lean. Keep in mind here that the incoming fuel also brings the oil with it. So lean is less oil, higher RPM's and higher EGT's.....all a recipe for disaster with any chainsaw......

 

[btmonnat]

I don't use one here and from what I can tell the CS-620P's are not limited. There really isn't a "safe no load RPM" for any saw. Far more important is to make sure that it is four-stroking nicely but cleans up and pulls hard in the cut as soon as you put load on it. During the cut, if you remove the load it should start four stroking nicely once again.

When tuning saws it is ALWAYS better to "sneak" up on the perfect tune by starting out rich enough it's four stroking pretty heavy and a tad down on power. Richen it up with each cut till it starts cleaning up nicely in the cut and making best power. If yoiu aren't exactly sure where that is ALWAYS er a tad rich vs a tad lean. Keep in mind here that the incoming fuel also brings the oil with it. So lean is less oil, higher RPM's and higher EGT's.....all a recipe for disaster with any chainsaw......

Sounds like a very good plan. I completely understand the 4 stroking. 67 years old and plan on this being my last saw purchase. Probably missing something by staying away from the autotunes but I think the less modern saws lifespan is going to be much better and anything to do with an autotune is going to be expensive to fix. I can still work on these. They have made these new saws so you have to take them back to be plugged in, at least that's my understanding. Thank you

 

[Cliff R]

I like simple and the CS-620P's are very easy to work on and every single part easily available for them. The most common problem I've seen with CS-590's, 600's, 600P's and 620P's are like everything else out there, leaving fuel in them for extended periods of time. Even marine or "recreational" fuel goes bad in a vented system after long periods of sitting. I've had small generators come in the shop that sat 3-4 years with fuel in them that would not run simply because the fuel wasn't any good. Replace the fuel, quickly clean out the main jet in the carb with a small piece of spring wire or precision drill bit in a pin vise and they roar to life instantly when they are filled with fresh fuel.

LOTS of opinions on currently available gasoline but common sense applies to ALL small power equipment that you own. Run the carb dry and drain the tank IF you are done with it for the season. Cripe, what's a tank of fuel cost in a CS-620P saw, couldn't be more than 50 cents worth if it was full......

 

[btmonnat]

I like simple and the CS-620P's are very easy to work on and every single part easily available for them. The most common problem I've seen with CS-590's, 600's, 600P's and 620P's are like everything else out there, leaving fuel in them for extended periods of time. Even marine or "recreational" fuel goes bad in a vented system after long periods of sitting. I've had small generators come in the shop that sat 3-4 years with fuel in them that would not run simply because the fuel wasn't any good. Replace the fuel, quickly clean out the main jet in the carb with a small piece of spring wire or precision drill bit in a pin vise and they roar to life instantly when they are filled with fresh fuel.

LOTS of opinions on currently available gasoline but common sense applies to ALL small power equipment that you own. Run the carb dry and drain the tank IF you are done with it for the season. Cripe, what's a tank of fuel cost in a CS-620P saw, couldn't be more than 50 cents worth if it was full......

I never let fuel set in mine if not using it. If not going to be run for awhile, I pour it out and start the saw and let the saw run till it quits and I only burn premix or non ethanol. Only other question I would have is why would you even have to reinstall the limiters after trimming the tabs off? Maybe I am missing something because warranty would be void anyway if they see the tabs were cut off. Got to tell you, I have loved this site for years. Great place to get answers, just sayin

 

[Cliff R]

Two reasons. Makes them a LOT easier to access with a flat tip screwdriver and make adjustments. If you put the limiters back in place and the metal retainer over them you can't tell if they have been tampered with......

 

[btmonnat]

Two reasons. Makes them a LOT easier to access with a flat tip screwdriver and make adjustments. If you put the limiters back in place and the metal retainer over them you can't tell if they have been tampered with......

Kind of what I thought, thank you. My self-confidence is at an all-time low. lol

 

[EchovsStihl63]

I don't use one here and from what I can tell the CS-620P's are not limited. There really isn't a "safe no load RPM" for any saw. Far more important is to make sure that it is four-stroking nicely but cleans up and pulls hard in the cut as soon as you put load on it. During the cut, if you remove the load it should start four stroking nicely once again.

When tuning saws it is ALWAYS better to "sneak" up on the perfect tune by starting out rich enough it's four stroking pretty heavy and a tad down on power. Richen it up with each cut till it starts cleaning up nicely in the cut and making best power. If yoiu aren't exactly sure where that is ALWAYS er a tad rich vs a tad lean. Keep in mind here that the incoming fuel also brings the oil with it. So lean is less oil, higher RPM's and higher EGT's.....all a recipe for disaster with any chainsaw......

Very good advice, better a tad rich than a tad lean!

Your method sounds very similar to mine. I'll rough set it on the bench before heading out to the woods, usually on the rich side. Then I will find the largest log I can find and actually set the high screw while its pulling in the wood at WOT. Take the H adjustment and turn it rich until its clearly four stroking while cutting and then slowly start leaning it out giving it time to respond to the change until it clears up and starts pulling hard.

It helps to have someone else running the saw to do it this way, but if you know what you're doing and have a steady hand you can do it yourself.

Now having said all of that I need to go remove the caps on my 620 and dial her in before I run it any more

 

[ihookem]

CliffR, I imagine the saw will freeze up and ruin the engine if the limiter caps are not taken out huh? I figured out how to take them out via Youtube.. However, I don't know how much to cut off of the caps.. Do I just file off 1/8" off the bottom of the red caps??? Or, do I file the little fins off ? I am not sure. I do know that the ECHO 620 I have was tuned by the guys at the shop and the H screw is screwed out counter clockwise as far as it will go... . I hope that is not too lean.. It has been a while since I ran it so I dont remember if it 4 strokes.

 

[btmonnat]

CliffR, I imagine the saw will freeze up and ruin the engine if the limiter caps are not taken out huh? I figured out how to take them out via Youtube.. However, I don't know how much to cut off of the caps.. Do I just file off 1/8" off the bottom of the red caps??? Or, do I file the little fins off ? I am not sure. I do know that the ECHO 620 I have was tuned by the guys at the shop and the H screw is screwed out counter clockwise as far as it will go... . I hope that is not too lean.. It has been a while since I ran it so I dont remember if it 4 strokes.

I just cut those tabs off with a utility knife that stop it from completely turning. Then reinstalled them. Should be able to completely turn it wherever you want. I ordered some new ones in case of a warranty issue, I could change them out.