Echo CS-500P Muffler Mod

[2lumbarleft]

I finally got around to field checking a new Echo CS-500P chainsaw that I was about to place into service. My first impression was very favorable. For a new engine with factory settings, it seemed to run remarkably well, and offered the promise of being a real screamer with a little tweaking. I removed the muffler and found there is not much that needs to be done with it. I removed the exhaust deflector, screen, and then the short tube with flange which is directly underneath. All that short tube does is restrict exhaust flow a little and perhaps decrease gas turbulence, but can't be of any serious consequence when you look at how restrictive the deflector was. There were only three little micro slots, and then a very small side slot that all combined, made me wonder how this saw could even run in the first place. Where the small side slot exists, and you will probably only understand this when you have it in your hands doing the same thing, I took a hack saw and made one small vertical cut which allowed me to lift and bend the newly created small tab outward, preserving it as a nice deflective shute. I re-installed the muffler and components, minus the tube and flange. I then richened the high speed jet "pig rich" and went to work on a large log out back. As I leaned the high speed jet, I could feel the power increasing until the thresh hold of no more increases, and then I slightly re-richened. I counted the turns, and amazingly, it was very close to the original factory setting which was 3 1/8 turns out, and I was 3 3/8 turns out. The low speed jet is best at around 1 1/2 turns out. There was no significant increase in noise. As far as power, I can't say that much was gained, and that surprised me. To give a power comparison is very subjective, but to give a relative comparison to a saw that most people would be familiar with, I would say it cuts about the same speed as a Husqvarna 450 Rancher (non-modified but properly tuned) with exactly the same bar and chain installed. In fact, I use the very same WoodlandPro universal bar and chain on both saws, so the comparison is apple to apple. If the horsepower rating for the Husqvarna is accurate, I would have to say that the CS-500P puts out about 3.2 horsepower after the muffler mod, but once again, that is very subjective. The dramatic power increase as in 30% as witnessed in modifying the CS-400 never occurred. I would say, maybe 10-15% gain at tops. I think the carb is too small to allow for a significant increases. I have more powerful 50 cc saws, but if you buy it right, this little CS-500P will be one of your favorites. It has great balance, and is light weight. With spikes the powerhead weighs about 10.8 pounds on my scale. That is about .45 pounds lighter than a Husqvarna 450 with spikes, but I am not comparing quality. The Echo is a way better constructed saw with vertically split magnesium engine housing, magnesium clutch plate, and adjustable oiler. It has very good AV and a great air particle separation system for maintaining clean air filters (about as good as Husqvarna I would say). It is an easy starting, dead nuts reliable saw (I have other CS-500P saws, so I can say that) and will probably be one of your favorites, "even if you can't figure out why." I know I can't, but I keep grabbing for this saw.

 

[cedarshark]

Its very odd the way Echo sets their carbs from the factory. I bought a used cs620P 2 weeks ago with a toasted top end. During the rebuild, I pulled the limit caps and the "H" screw was 1/2 turn off bottom. Way too lean and the reason the saw ate the top end.

 

[Chris-PA]

Its very odd the way Echo sets their carbs from the factory. I bought a used cs620P 2 weeks ago with a toasted top end. During the rebuild, I pulled the limit caps and the "H" screw was 1/2 turn off bottom. Way too lean and the reason the saw ate the top end.

It isn't really odd - they are selling saws that meet emissions limits while having incorporated no technological changes to address the two main causes of unburned fuel going out the exhaust (scavenging losses and carbs that puke fuel as soon as the air velocity increases a little bit). The strategy of slapping limiter caps on the same old designs has failed in every industry that has tried it, even with 4-strokes that never had those two problems listed above.

I have wasted my hard earned money on things like generators with non-adjustable carbs that simply could not run properly. I would never do it again, so unless the manufacturer has done some actual design work to address the issue I would not even consider it. I can modify a saw just fine, but a product should work reliably as it is sold.

 

[cedarshark]

It isn't really odd - they are selling saws that meet emissions limits while having incorporated no technological changes to address the two main causes of unburned fuel going out the exhaust (scavenging losses and carbs that puke fuel as soon as the air velocity increases a little bit). The strategy of slapping limiter caps on the same old designs has failed in every industry that has tried it, even with 4-strokes that never had those two problems listed above.

I have wasted my hard earned money on things like generators with non-adjustable carbs that simply could not run properly. I would never do it again, so unless the manufacturer has done some actual design work to address the issue I would not even consider it. I can modify a saw just fine, but a product should work reliably as it is sold.

I understand your point, but what I find odd is, my cs590 Timberwolf was 2 1/2 turns out on the H screw. I know they are different carbs but that much variance is weird.

 

[STIHLTHEDEERE]

It isn't really odd - they are selling saws that meet emissions limits while having incorporated no technological changes to address the two main causes of unburned fuel going out the exhaust (scavenging losses and carbs that puke fuel as soon as the air velocity increases a little bit). The strategy of slapping limiter caps on the same old designs has failed in every industry that has tried it, even with 4-strokes that never had those two problems listed above.

I have wasted my hard earned money on things like generators with non-adjustable carbs that simply could not run properly. I would never do it again, so unless the manufacturer has done some actual design work to address the issue I would not even consider it. I can modify a saw just fine, but a product should work reliably as it is sold.

I have found that on most of the new 4-stroke engines that have nonadjustable carbs, you have actually go in and swap out jets to get them to start-run properly.

 

[Chris-PA]

I have found that on most of the new 4-stroke engines that have nonadjustable carbs, you have actually go in and swap out jets to get them to start-run properly.

Yes, in the case of my generator I just put on an old adjustable carb.

 

[CR888]

l recently bought a 550p out of the US from an AS member and it was not broken in yet and l had no warranty. So l was reluctant to take it out sawing until l knew it was tuned correctly as everyone seems to say they are dangerously lean. The tabs were out as far as the limiters would allow when it arrived but before they were removed l wanted to see how these saws were setup from the factory/dealer. So l warmed it up briefly ready to make some cuts and the saw idled, spooled up and appeared to four stroke as it was. lt was a bit tricky with the limiter confusing the four stroking but l felt the carb was setup acceptably despite H&L being against the limiters. l removed the limeters and richened the H to where l was comfortable but as said the rev limited don't make tuning easier. I pulled th muffler to have a look at p/c and did not believe it was to restricted, l have certainly seen far far worse. OEM's either went down the strato road or fitted catalatic converters to keep their saws compliant. l like my echo so far despite being a bit fat and heavy.

 

[2lumbarleft]

l recently bought a 550p out of the US from an AS member and it was not broken in yet and l had no warranty. So l was reluctant to take it out sawing until l knew it was tuned correctly as everyone seems to say they are dangerously lean. The tabs were out as far as the limiters would allow when it arrived but before they were removed l wanted to see how these saws were setup from the factory/dealer. So l warmed it up briefly ready to make some cuts and the saw idled, spooled up and appeared to four stroke as it was. lt was a bit tricky with the limiter confusing the four stroking but l felt the carb was setup acceptably despite H&L being against the limiters. l removed the limeters and richened the H to where l was comfortable but as said the rev limited don't make tuning easier. I pulled th muffler to have a look at p/c and did not believe it was to restricted, l have certainly seen far far worse. OEM's either went down the strato road or fitted catalatic converters to keep their saws compliant. l like my echo so far despite being a bit fat and heavy.

I have to say, that out of all the Echo saws, the 550P remains a mystery to me on how they sell any saws of this particular model. It is heavy as the 600P at 13.3 lbs if memory serves correctly, and it is more expensive than their CS-590 timber wolf with the 60 cc engine. I don't have that model, but it must provide satisfaction to those that own them. Out of curiosity, did you check to see how many turns out the factory had set the carb before you richened it up and started the tuning process?

 

[bikemike]

Yeah i like my echos just got a power head for 6 bucks and its a cs510 50cc. Gutting the can and welding in a 1/8 inch bigger discharge tube and going to find a bigger carb for it. When it comes to tunning and how many turns out they are. I dont pay attention to that. When i get them new i put a fine thread sheet rock screw in it finger tight then turn caps to the leanest position. Then pull on the screw and out the caps go so i can fatten up to run good and idle nice. Almost everything these days runs a bit leaner than they should. But thats a good thing tears up engines. Or ppl get pissed and get rid of them cheep. So ppl like me get good deals. And keeps techs working

 

[STIHLTHEDEERE]

i think, but not positive on this, the 550p is a strato saw? so it would be their "clean" model for epa points?? i believe it is a 600p with a smaller strato top-end.

 

[Chris-PA]

i think, but not positive on this, the 550p is a strato saw? so it would be their "clean" model for epa points?? i believe it is a 600p with a smaller strato top-end.

Hey, I just checked out the IPL and it looks like it is! Echo finally ponied up and did it the right way, so I have to retract my comment above. Good for them - better late than never I guess.

 

[cedarshark]

The 550p is certainly a different cylinder than the 620p I rebuilt today.

 

[BGE541]

Would the 550P be porting worthy? Anything look promising in the design?

 

[bikemike]

Would the 550P be porting worthy? Anything look promising in the design?

I think everything thing could be worth porting just depends on if you want to be mild or go wild for the longevity of the saw. Even just a good muffler mod can go a long ways