Echo cs 490 porting

[drf256]

Stuck at 13,500. With air filter, without air filter. Leaner, richer. For richer, for poorer, etc....

Do you think it gained?

 

[drf256]

Looks like it gained 1.5 sec.

 

[bikemike]

Stuck at 13,500. With air filter, without air filter. Leaner, richer. For richer, for poorer, etc....

Do you think it gained?

It's the coil. In the cut it sounds like it has much higher rpm then the vid without carb mod. I'd leave it for a bit and burn a gallon or 2 through it then do another vid. I se a difference or hear the difference. Wish echo was like that stock. Hits rev limiter very fast from idle

 

[Backtroller]

It's snappy and doesn't sound like any other echo I've ever heard. I think that is impressive. It really cut through the big wood nicely.

1.5 seconds is a big gain. Wonder what it gained over totally stock form?

 

[Canadian farm boy]

Time to pull #2 out of the box and do some cutting. Then compare the two saws

 

[drf256]

It's snappy and doesn't sound like any other echo I've ever heard. I think that is impressive. It really cut through the big wood nicely.

1.5 seconds is a big gain. Wonder what it gained over totally stock form?

I think I got a 32.45674328765% gain.

 

[Backtroller]

Damn right! Now if you had only went to the ten billionths place I'd question your gains

 

[paragonbuilder]

I think I got a 32.45674328765% gain.

Can you please document your calculations for us?

 

[Red97]

Well here goes. I'm guilty of not taking the time to tune in wood. Had 4 stroking, not as much as before. Feels faster, possibly less torquey than the smaller Venturi when the RPMs drop. Possibly.

Can anyone guess Max RPMs? It was the same with our without air filter.

Unfortunately, my fast tach doesn't lend well to being mounted to a saw. It did some weird stuff at max rpm.

After carb mods:

Oak Block

12" log

It definitely, likes the bigger carb. Now I got some more research to to do to find a suitable coil replacement...

Very through work sir.

 

[drf256]

Can you please document your calculations for us?

My flux capacitor has arterial monochromia, so the calculation my be off by a billionth or so.

 

[mdavlee]

Looking better.

 

[Deets066]

Looking better.

Not bad for an echo huh

 

[Deets066]

You run it side by side with a 260 yet Doc?

 

[drf256]

You run it side by side with a 260 yet Doc?

No.

I don't have a well built 026 at present. Last I did is at the NY GTG, where I wont be.

I also have to get a 16" echo bar so I can compare the 2 equally.

 

[Red97]

Got home late last night. It on like donkey Kong tomorrow....

 

[Red97]

I'm thinking
air filter modification
bar/chains .325×7×8 18" 3/8×7 16" and picco×7 16"or 18"
Then move onto carb mods.

Anything else you guys want to see tested, or tried?

 

[Deets066]

I'm thinking
air filter modification
bar/chains .325×7×8 18" 3/8×7 16" and picco×7 16"or 18"
Then move onto carb mods.

Anything else you guys want to see tested, or tried?

Unlimited coil

 

[Red97]

Unlimited coil

Al and I are woking on that.... to the tune of 14-14.5k

I have a couple other options I'm looking into as well.

 

[drf256]

Unloaded, my saw stays at the same 13,500 with or without the air filter. It didn't do that before the carb mods, it had dropped 500 rpm with the filter prior.

The unlimited coil sounds interesting. I'm wondering if the limited coil may be why this saw doesn't want any timing advance.

If the saw isn't turning more than 13,000 with the bar buried, will an unlimited coil make it any faster/stronger?

 

[drf256]

I have metal mesh here, so an AF mod should be easy. I'm wondering if the AF cover needs to be vented Red.

I have a 16" bar for a Husky 346 in .325. I also have a 14" echo bar in 3/8 LP- waiting on a sprocket.

I'm working for the next 9 days. May have a break in the action on Sunday to play.