Porting an Echo 303t

[Nutball]

I got a new 303t, I've never been a fan of some weird features I noticed on one years ago: mainly it being the only model with a throttle lock and the off switch not on the handle.

Man, is it weird, just backwards. A full throttle lock, not safe, it could get set by a stick during use, then drop the saw or something and it's running full throttle by your feet. The off switch seems inconveniently placed, the starter handle is square and uncomfortable, it appears to have a shaft driven oiler, not clutch driven, the gas tank is in front and oil in back, the carb is up front too, side choke, top primer bulb could get poked by sticks easily, MINI bar nuts!, it even came with a bottle of 50:1 (which usually only comes with non pro grade saws). Seems like this is a non pro grade top handle saw, kinda strange, but not a problem. Maybe it is popular in the same countries that still use the 070.

I'm also not a fan of the exposed tensioner gearbox where wood chips can easily get in and jam it.

Maybe it will be easy to work on?

We shall see. I got it for the fun of it, I'll try modding it and see what happens.

 

[Nutball]

I have idled and revved around 1/2 tank of gas while making this post, so it has a head start on break in for better cut times before modding.

 

[Nutball]

And Phillips screws everywhere, I hate those on something like this. And blunt plastic nubs in place of spikes!

 

[smokey7]

Idling and miss revving is not the best way to break in a engine. Load is what seats the rings.

 

[Nutball]

Thanks for the info.

I got a few test cuts in and it is slow as expected. It also has a reed valve. How do I modify a reed valve?

 

[Nutball]

Practically no blowdown

 

[Nutball]

Not pretty, but really improves flow. Those cats are tougher than they look.

 

[Onan18]

You have to look at when a chassis was first designed. The 303 started life as the 3000 in the early 80s IIRC. Back then top handle saws were still in their infancy from a design standpoint.

 

[Nutball]

I like the cylinder design: 90 degree ports instead of rotated ports and elbow exhaust like the other Echos

 

[qurotro]

That's the antique echo CS-3000... I'm surprised they still make that...

 

[Nutball]

I'm surprised they haven't updated it, well it looks like an updated 3000. What specs I could find show less power than a 2511t, but I think there's a lot hidden away in this engine if the tiny carb and reed valve don't choke it.

Apparently they made a rear handle version (306), which I think is discontinued, but google thinks HD's near me still have them. It also looks like Home depot is offering some of the random chinese 52cc saws on their website, but I didn't see a 306.


Muffler mod internal drawing added to an earlier post.

 

[Wood Doctor]

After reading all this, maybe this is why I really like my Echo CS-330T and my much older CS-340. Both start and run flawlessly and have the extra strong hook/loop in the back. These and the one shown here for the CS-303T make the Sihl equivalents look and perform like toys for climbers.

 

[Nutball]

It seems like a really simple design to work on. I just can't work on it now since I hurt my wrist, which I have no idea how I hurt it in the first place.

 

[Nutball]

 

[FergusonTO35]

I have its older brother, the CS-3000. Call me weird, but I like the design better than just about any other top handle. I totally rebuilt mine when I first got it and thought it was quite easy. I really dont mind it being slower than the latest and greatest, considering it is an old design and I just use it for small stuff. Hint: my understanding is the older non-cat mufflers for the 3000, 301, 302, 3400 etc. will bolt right on. If you ever get tired of it I might be interested!

 

[Nutball]

I've only seen good reviews for it on the Echo USA website. I'll keep you in mind. I just need to see how it turns out, and get a feel for using it.

 

[Nutball]

Exhaust is 119 degrees where it is about to open to the flat top of the piston, it leaks light a couple degrees earlier.

Transfers open about 10 degrees later

.040 squish

Pic of when the transfers start opening

 

[a. palmer jr.]

I have a 330T and found an older Echo muffler without the cat and bolted it on, makes it run a lot better than the cat version and cooler also...

 

[Nutball]

Japanese cross screws on the crankcase is garbage. I had to impact drive 3 out and the 4th needed a stripped screw remover. How could they not learn to use a socket type head for a high torque screw?

 

[FergusonTO35]

That's one of the oddest things about Japanese machines, they have utmost faith in screw heads.