Why echo? 300$ with 18" .325 bar, chain. One of the lightest 50cc saws around, even come with a small spline rim setup. Decent comp for a stock saw. Not a lot of flow imo. Stock timing numbers. Intake 71/82 (comes to a point at the bottom, exhaust 114 transfers 125. Cut .053 off the base. # 88 intake 121 exhaust 131 transfers. Piston has a 7* dome, so I cut the squishband parallel. If using a madrel make sure the cutter isn't too long... Squish set at .018 Marks by the plug is from my dumazz attack. Leaving the tool bit too long... Set exhaust at 106, worried it would break through the roof... Transfers set at 125, yes it has removable covers, but wanted the practice with the rt angle hand piece. First post here, may as well be a build thread ( bcroftb) invited me over probably butchered the name lol
Part 2 Roughed up the intake, widening it and raising it back to stock location. Glueed the jug on via permatex 51813. Added a second muffler port. Sporting one of my new medium deflectors 100% out of the box stock carb limiters and all. .325 oregon semi chisel. Ported same stock chain. With .325 stihl rs My ported 346, wearing the same stihl rs chain. Enjoy
Modified a Picco rim to fit this thing. Added some oil holes to a 18" lo pro poulan bar Same log as all the other clips. I sure am liking the 3 jaw chuck for these type of things. Boring the picco rim out. Just cut the splines with a small burr. Little bit at a time until I got the fit I wanted.
Started on some carb mods.... Venturi opened from 14.25 to 15.6, stock carb has 13.5. Choke bore opened from 16mm, to 18mm same as stock. Got into a passage trying to blend into the venturi, just a lil pin hole... This one to be exact. Going to fill it with jb, and redrill it. My zama option was an absolute disaster... tiny choke opening stock but listed as a 14.6 venturi. Tryed opening the choke to 18mm, same as a c3el32. And venturi to 15mm That is the needle visible lol and a couple other passages in the venturi. Not a viable performance option.
Made these gizmos for the choke linkage. These carbs have a long choke rod, with the plate peened into position. Something like this. Moved the impulse to the top cover, filled my oops hole and the old impulse with jb weld. Really hoping this new coil will gI've me an extra 1000-1500 rpm.
Better pic of how I mounted the a/f cover. Carb on the left is the one I opened up. Old and new choke plate. Stock echo carb on the right. Modified on the left. Good thing I pulled the welch. Hacked away the throttle stop plate, as it was hitting the intake wall. Only to find out my other replacement carb has the correct stop. Lol Like a glove..... With modified carb, same test log as stock. Has a pop to the idle I have never noticed before, sounds just like a 346 now. Dumb luck the carb even worked.
20" 3/8×7 Same bar/chain. While not the fastest setup, I was mighty impressed with how it pulled it. Seems the more fuel I get through it, the less it wants to clean up in the cut. Bar took 69 dl It is going to get a 18" lo pro bar, because I do not like the way the full 3/8 acts while limbing. Plus I just bough a couple nice lo pro bars. Lol[/QUOTE]
Switched to full comp 3/8 and that is a nasty hard maple crotch the tip was just poking out the other side. Just to see what it would do. OK I'm done now lol
I still can't believe how well it pulled that 32! That was cottonwood wasn't it? What do you think HoneyFuzz pretty good for an Echo huh?
Thank you, stayed in the shadows for a bit, then was convinced to join. Figured no better way than to start a build thread. Yeh cotton wood, cut 1.5-2 seconds quicker with full comp... Lol, sold my ported 346xp cause of this lil critter. Thank you sir.
Red97 do have a baseline of just the muff mod for the Echo? p.s. build threads are fun, I bet others would like the end results on the Dolmar 421 of yours from OPE - seems to be a popular little bugger
I do not have that baseline sorry. Always do the muffler mod last. I will try and get the 421 thread over here today.
Joe, When we finally get together you can use my muffler modded 490 as a baseline. I'm going to keep it stock for awhile.
I'm very impressed lol !!! You know I love Echo....but a 32" bar on a 490 .....holy crap that's awesome !! Thanks for the great thread !!!
