Echo 4910/501p “shortcomings”

[Dolkitafreak]

As some know, I’m quite a fan of these little guys in ported form. Tons of features I love about them.

Some called these a 346 killer, I don’t know about all that but I think it’s a possibility. These saws are consistently hitting 5.5hp on @Red97 ’s dyno, that’s pretty impressive for a $300 50cc saw!

On Facebook @huskihl mentioned a few things that he felt really hindered these saws from becoming the rocket ship that 346’s can be. What I’m hoping of this thread is that guys who are experienced with these can point out what we feel like holds these back, and what we can do to make them even stronger. I’ll put up a few pics to get the conversation going! I didn’t go in depth with Kevin on Facebook because most there are too dense to understand, and it’s better recorded here. He mentioned exhaust port width, carb, and transfer issues hold them back. Curious what others think about these little guys.

Not a dig at Kevin, I don’t disagree with him, just wanna see if collectively some ideas can be kicked around, for fun and stuffs.

 

[Dolkitafreak]

Stock pics here mostly

 

[Dolkitafreak]

 

[Dolkitafreak]

The piston pictures are with a stock 346 NE piston just for comparison. Alright guys, what downfalls do we see here and what can be done to fix?

 

[huskihl]

As some know, I’m quite a fan of these little guys in ported form. Tons of features I love about them.

Some called these a 346 killer, I don’t know about all that but I think it’s a possibility. These saws are consistently hitting 5.5hp on @Red97 ’s dyno, that’s pretty impressive for a $300 50cc saw!

On Facebook @huskihl mentioned a few things that he felt really hindered these saws from becoming the rocket ship that 346’s can be. What I’m hoping of this thread is that guys who are experienced with these can point out what we feel like holds these back, and what we can do to make them even stronger. I’ll put up a few pics to get the conversation going! I didn’t go in depth with Kevin on Facebook because most there are too dense to understand, and it’s better recorded here. He mentioned exhaust port width, carb, and transfer issues hold them back. Curious what others think about these little guys.

Not a dig at Kevin, I don’t disagree with him, just wanna see if collectively some ideas can be kicked around, for fun and stuffs.

5.5hp …is that ported I’m guessing?

Thanks for the mention. I love the saw; built well, great oiler, priced right. I’ve only ever been into this one, and that was only once so far until I get some time. So other guys could very well be getting more out of them

 

[Dolkitafreak]

5.5hp …is that ported I’m guessing?

Thanks for the mention. I love the saw; built well, great oiler, priced right. I’ve only ever been into this one, and that was only once so far until I get some time. So other guys could very well be getting more out of them

Yes the 5.5hp is ported, stock they’re a messily 3.25 hp approximately lol.

The carb and exhaust width I can see, what do you dislike about the transfers?

 

[Dolkitafreak]

Joe has done quite a few of these now, hopefully he chimes in!

 

[huskihl]

Yes the 5.5hp is ported, stock they’re a messily 3.25 hp approximately lol.

The carb and exhaust width I can see, what do you dislike about the transfers?

Not a fan of the secondaries being twice the size of the mains. Don’t know if it matters or not, it just doesn’t fit into my MO

 

[Dolkitafreak]

Not a fan of the secondaries being twice the size of the mains. Don’t know if it matters or not, it just doesn’t fit into my MO

Makes sense. I wondered what other guys were doing with those. Anyone know if Mitch Weber is on here? He’s built lots too.

I raised my mains and left the secondaries bone stock with great results, I wonder about taking t he ramp out if it would help.

 

[huskihl]

Makes sense. I wondered what other guys were doing with those. Anyone know if Mitch Weber is on here? He’s built lots too.

I raised my mains and left the secondaries bone stock with great results, I wonder about taking t he ramp out if it would help.

I believe I did something similar. The ramp kinda helps the charge swirl up and around. But it’s a bunch more than most saws

 

[farminkarman]

Joe has done quite a few of these now, hopefully he chimes in!

I would think Joe has found a few things. I have one of these from Joe, and it is a great running saw.

 

[huskihl]

Mitch used to be on here but hasn’t been for awhile

 

[Dolkitafreak]

It ends up being a huge stagger between them, but it seems like I’m getting the benefit of fast response from the low blowdown on the main and keep torque with the lower secondary. It’s worked for me but I didn’t know how others are doing it!

 

[huskihl]

It ends up being a huge stagger between them, but it seems like I’m getting the benefit of fast response from the low blowdown on the main and keep torque with the lower secondary. It’s worked for me but I didn’t know how others are doing it!View attachment 321878

Must’ve been a different saw. Mine aren’t that far apart I don’t believe

 

[Dolkitafreak]

Must’ve been a different saw. Mine aren’t that far apart I don’t believe

That one is with the base cut .040” and the main raised to 122

 

[huskihl]

Must’ve been a different saw. Mine aren’t that far apart I don’t believe

I looked and the only pictures I have are the base and squish band cuts. Didn’t take any pictures since it was for myself

 

[Dolkitafreak]

I looked and the only pictures I have are the base and squish band cuts. Didn’t take any pictures since it was for myself

The two I’ve done were just base cut, my personal saw has exhaust at 102 and 190 psi with .038” off the base. Were you able to pump yours up a good bit more?

 

[huskihl]

The two I’ve done were just base cut, my personal saw has exhaust at 102 and 190 psi with .038” off the base. Were you able to pump yours up a good bit more?

.040 from the band and 106-7 on the exhaust. I didn’t figure I could keep the walls and roof straight without going through at 104

 

[Dolkitafreak]

.040 from the band and 106-7 on the exhaust. I didn’t figure I could keep the walls and roof straight without going through at 104

Yours should have boatloads of compression, should pull like a freight train!

 

[Red97]

Itty bitty carb dosent help at all.

I really want to try the full circle 490 piston in one.