Miller Mod Saws and the Echo CS-500P

[fordf150]

Wow that's a small carb. My husky 136 36cc has a walbro wt540 with .530" 13.4 something mm venturi View attachment 479477 punch the venturi out a bit to drop a bigger test carb on it

13.49mm. To some extent there is more than just venturi size that determines flow. Not familiar with that carb but some of these carbs have a nozzle that protrudes quite far out into the venturi

 

[bikemike]

My echo 360t 36cc has a venturi opening stock at it was much smaller bore than the 201Turd so I punched it out to this and saw took nice to it. Idle mid range transition and wot. It was tested in below 0 Temps ran a tank through it and no problems my opinion on why a properly tuned echo last so long is cause they equip them to be under powered

 

[bikemike]

13.49mm. To some extent there is more than just venturi size that determines flow. Not familiar with that carb but some of these carbs have a nozzle that protrudes quite far out into the venturi

Yeah that is the fuel delivery nozzle or atomizer for the high circuit. From what I seen in the ported pics I think the saw could use a bigger carb if it only has half an inch to suck through. One set of transfer ports alone can handle everything that carb has to offer

 

[Chris-PA]

That WT is not uncommon on 50cc saws - the RedMax G5000 had one too, as well as others. It would be fine with the stock porting here too. If you were not changing the carb then it might determine how you go with the port timing, focusing more on lower rpm power.

 

[bikemike]

That WT is not uncommon on 50cc saws - the RedMax G5000 had one too, as well as others. It would be fine with the stock porting here too. If you were not changing the carb then it might determine how you go with the port timing, focusing more on lower rpm power.

Yeah in comparison with the 026 stihl they look very choked off vs stihl. I think a small carb can still perform good. The saw in the vid had a nice improvement to it

 

[MillerModSaws]

Let's finish this thread up boys.

I will tell you we flat ran out of carb. This saw will only turn a little over 13k unloaded. Just needs more carb but that said they turned out really nice. I'm gonna tell ya where I landed on both saws and then we can discuss.

 

[MillerModSaws]

Saw #1
I took .030 from the base
Cut the squish on a 3° angle and reset to .020
I epoxied the intake it's set at 62% width
The exhaust is at 65% width and I raised the roof and floor of the exit about 1mm each.
Has a dual port muffler
108/123/75ish
This is the stronger of the 2 saws however that said it also has more runtime on it
Both saws are holding around 11800 in the cut this saw just holds it much easier

 

[MillerModSaws]

Saw#2
Took .035 from the base
Cut squish the same
Exhaust is the same
Muffler the same
The intake is untouched on this saw
108/124/86 is the numbers in her.
Like I said this saw dosnt hold the rpm quite as well but it maybe the fact of less run time! Both are running pretty identical other than that.

 

[MillerModSaws]

Idk how many of ya get to cut this fabulous wood. But in my neck of the woods ain't nothing that'll kill a saws power faster the hedge. Lol. I'll try and get a final vid but I need to order up a new chain. Put me some lgx on her and throw her in some oak to give ya a good vid.

 

[bikemike]

Looks good. Echos take a while to free up..
What epoxy are you using for the intake?

 

[MillerModSaws]

Looks good. Echos take a while to free up..
What epoxy are you using for the intake?

Well. I actually tried some new stuff here. This one has the morso/edelbrock A B epoxy in it. But take your pic. These are the 3 I have been plating with!

 

[Chris-PA]

Running 9,500 to 10,000rpm in the cut under load. Probably not much more that can be done given the limited size of the carb.

 

[MillerModSaws]

Running 9,500 to 10,000rpm in the cut under load. Probably not much more that can be done given the limited size of the carb.

Good thing these are running more. As you see it going threw that hedge there maintaining 11600-11800 pretty good. Dog it in and pull it threw you'll pull them down to the 11200 range.

 

[Chris-PA]

Good thing these are running more. As you see it going threw that hedge there maintaining 11600-11800 pretty good. Dog it in and pull it threw you'll pull them down to the 11200 range.

I'm afraid it's only running 9,500 to 10,000rpm in that video. Below is a sample from the first cut, but they're all pretty similar.

I was not implying that you didn't do a good job with it at all. It's just that when you start with a 50cc saw that has porting as compromised as this one (in order to avoid paying for the rights to use strato) along with a WT of limited size, it takes a lot of mods to make it work well. I know some want to believe Echo has some magic formula and really smart engineers that allows them to do so much better than those saws that need strato to meet emissions, but the reality shows otherwise. With a lot of work you've made this a decent saw.

 

[MillerModSaws]

I'm afraid it's only running 9,500 to 10,000rpm in that video. Below is a sample from the first cut, but they're all pretty similar.

I was not implying that you didn't do a good job with it at all. It's just that when you start with a 50cc saw that has porting as compromised as this one (in order to avoid paying for the rights to use strato) along with a WT of limited size, it takes a lot of mods to make it work well. I know some want to believe Echo has some magic formula and really smart engineers that allows them to do so much better than those saws that need strato to meet emissions, but the reality shows otherwise. With a lot of work you've made this a decent saw.

View attachment 482921

And this is where I will end the discussions and go back to my other forums. I don't have some fancy computer system to tell me what it's running. I simply put a tac on it and watch the rpm.
I can also tell you Randy was kind enough to post his results on the other forum and our numbers ended up really close. And his statement was his saw would hold 11500-12000. I have no reason for lying. And I'm happy to let anyone around me come play with this saw and see the results for themselves.

 

[Chris-PA]

And this is where I will end the discussions and go back to my other forums. I don't have some fancy computer system to tell me what it's running. I simply put a tac on it and watch the rpm.
I can also tell you Randy was kind enough to post his results on the other forum and our numbers ended up really close. And his statement was his saw would hold 11500-12000. I have no reason for lying. And I'm happy to let anyone around me come play with this saw and see the results for themselves.

Good grief, I certainly never thought, said or implied you were lying. Quite frankly it's pretty obvious just from listening that saw is not turning over 11,000rpm under load, and the fancy computer system is just an audio spectrum plot. It's a shame a simple technical discussion gets someone so upset.

You did a good job getting what you did out of that saw given the starting point, it's just that it isn't magic and there are still limitations to the design (primarily the carb), as you have recognized and was clear from the beginning. What did you expect from it?

 

[bikemike]

Good grief, I certainly never thought, said or implied you were lying. Quite frankly it's pretty obvious just from listening that saw is not turning over 11,000rpm under load, and the fancy computer system is just an audio spectrum plot. It's a shame a simple technical discussion gets someone so upset.

You did a good job getting what you did out of that saw given the starting point, it's just that it isn't magic and there are still limitations to the design (primarily the carb), as you have recognized and was clear from the beginning. What did you expect from it?

Can someone send a pic of the back of the carb looking down the bore

 

[quotedraven]

Funny I had mine spinning at 16000 when it was very cold those shindaiwa motors are very tight. Just a muffler mod. Dont worry I got it down to 13000

 

[MillerModSaws]

Ok the statement earlier made me severely mad. I build saws cause I love to. Not for a living! If i took the statements wrong than I appoligize. I'm here to show what I've learned and nothing more!

 

[Hedgerow]

But where's your engineering degree carl??

What about the cool looking, colorful snapshot of your computer screen?