Texas HotSaw
ArboristSite Lurker
Well, having been involved with all sorts of racing over the past 45 years,
(karts, cycles, cars, RC toys, etc.)
when it came time to freshen up my little Echo, I could not help jacking with it a little
A little history on the saw.....
I plucked it out of the dumpster at a shop I worked at 18 years ago.
The guy who had it was tired of flogging a dead horse, and tossed it.
The bar & chain was worn out, and when looking in through the exhaust port, there were huge groves worn in the piston.
But an old p.o.s. mini-saw is better than no saw, and I live inside the city, and have really little use for one, other than a random limb getting to close to my roof now & then.
And even though it was on it's death beed, it still ran, and would knaw through anything I had.
The last time I fired it up before this summer was maybe 5 years ago.
So, when I needed to take an 8" tree out that was growing up between my fence boards, I pulled it off the shelf, wipped away 5 years of dust & cat hair, put gas in it, and tried to fire it up.
No fire, so I went after the carb.
The diaphragms were as hard as soda crackers.......
Arg, not wanting to actually spend $$ on a kit, I through them in a bowl of tire softener.
Dang if it didn't work.
Although, an 8" tree was almost too much for the old dog to handle, and the bar was so worn that the chain kept derailing off the front roller sprocket, and locking up, I managed to get the tree down, and cut up enough to get rid of.
But it made for a frustrating day.
So, I went to eBay, to see what a few parts would cost.
A bar here, a chain there, a new clutch drum, a carb kit, crank seals, and a used piston & cylinder were soon on their way to me.
While searching for a carb kit, I found that the little WA Walbro is used on the little pocket bikes, and that there were larger versions out there.
My WA-5 had a 11.2mm bore, and found that a WA-82 had a 12.7mm bore. So I ordered in a used one.
I also picked up an Atom igniton module so that I didn't have to deal with a point ignition.
When the piston came in, I scalloped the piston on the exhaust side, and cut the skirt on the intake side to get a little more port timing. (about .060" on both)
I was just in the process of doing piston coatings on my car engine, so the Echo piston received ceramic heat barrier on the dome, and moly anti-wear coating on the skirt.
I did not cut on any of the ports since this is a chrome bore cylinder, and have seen the chrome start to flake away from the aluminum around where someone 'ported' these types of cylinders.
I have ported chrome bore cylinders before, but then sent them off to be re-chromed afterwards.
Since this is a play thing, and I am not out to win any championships, I figured I would not go that far.
The new carb's throttle shaft, and idle adjustment did not match the Echo's requirements, so I swapped the shaft & fuel pump cover with those from the original carb.
While the shaft was out, thinned it on both sides of the butterfly screw to gain a little more flow area.
The plastic intake manifold had some serious sharp-edged mold marks in it, so those were ground down, and smoothed.
I also matched it to the intake port.
The original air filter wasn't much more than a 3" square piece of filter felt, and I just couldn't keep that......
And the filter mount plate sat very close to the mouth of the carb.
First, I drilled 6 holes in the mount plate, but I felt that was still not enough, so I moved it 5/16" farther away from the mouth of the carb with small spacers, and longer screws.
Then I dug through some old kart parts boxes, and found a K&N 3" diameter filter that I had never used.
It took a piece of 1/2" thick plastic to adapt the K&N to the Echo.
I mounted the Atom igniton module in the carb area because there wasn't much room for it under the flywheel.
Then I attacked the stock muffler.
First, I ground over hanging weld bead out of the flange.
Then drilled holes in the inner bafflel, reshapped some of the baffels to aid flow, and hammered a dome into the cover to increase volume inside the muffler.
(20/20 hind sight, I could have gained more volume by just replacing the cover with a flat piece, and longer screws & spacers)
But my plans are to eventually put a tuned pipe on it, and looking through eBay under 'pocket bike' and Zenoah (RC boat engine),
I came up with quite a few for under $50, some made from stainless steel.
Anyway, it's together, and really screams.
How much better does it cut than a stock 30cc Echo ?
No idea, never had a good stock one.
Total cost of parts: About $200 before getting a tuned pipe.
Yes, I could have probably bought a good used mini-saw for that much, but it would have not been as fun
(karts, cycles, cars, RC toys, etc.)
when it came time to freshen up my little Echo, I could not help jacking with it a little
A little history on the saw.....
I plucked it out of the dumpster at a shop I worked at 18 years ago.
The guy who had it was tired of flogging a dead horse, and tossed it.
The bar & chain was worn out, and when looking in through the exhaust port, there were huge groves worn in the piston.
But an old p.o.s. mini-saw is better than no saw, and I live inside the city, and have really little use for one, other than a random limb getting to close to my roof now & then.
And even though it was on it's death beed, it still ran, and would knaw through anything I had.
The last time I fired it up before this summer was maybe 5 years ago.
So, when I needed to take an 8" tree out that was growing up between my fence boards, I pulled it off the shelf, wipped away 5 years of dust & cat hair, put gas in it, and tried to fire it up.
No fire, so I went after the carb.
The diaphragms were as hard as soda crackers.......
Arg, not wanting to actually spend $$ on a kit, I through them in a bowl of tire softener.
Dang if it didn't work.
Although, an 8" tree was almost too much for the old dog to handle, and the bar was so worn that the chain kept derailing off the front roller sprocket, and locking up, I managed to get the tree down, and cut up enough to get rid of.
But it made for a frustrating day.
So, I went to eBay, to see what a few parts would cost.
A bar here, a chain there, a new clutch drum, a carb kit, crank seals, and a used piston & cylinder were soon on their way to me.
While searching for a carb kit, I found that the little WA Walbro is used on the little pocket bikes, and that there were larger versions out there.
My WA-5 had a 11.2mm bore, and found that a WA-82 had a 12.7mm bore. So I ordered in a used one.
I also picked up an Atom igniton module so that I didn't have to deal with a point ignition.
When the piston came in, I scalloped the piston on the exhaust side, and cut the skirt on the intake side to get a little more port timing. (about .060" on both)
I was just in the process of doing piston coatings on my car engine, so the Echo piston received ceramic heat barrier on the dome, and moly anti-wear coating on the skirt.
I did not cut on any of the ports since this is a chrome bore cylinder, and have seen the chrome start to flake away from the aluminum around where someone 'ported' these types of cylinders.
I have ported chrome bore cylinders before, but then sent them off to be re-chromed afterwards.
Since this is a play thing, and I am not out to win any championships, I figured I would not go that far.
The new carb's throttle shaft, and idle adjustment did not match the Echo's requirements, so I swapped the shaft & fuel pump cover with those from the original carb.
While the shaft was out, thinned it on both sides of the butterfly screw to gain a little more flow area.
The plastic intake manifold had some serious sharp-edged mold marks in it, so those were ground down, and smoothed.
I also matched it to the intake port.
The original air filter wasn't much more than a 3" square piece of filter felt, and I just couldn't keep that......
And the filter mount plate sat very close to the mouth of the carb.
First, I drilled 6 holes in the mount plate, but I felt that was still not enough, so I moved it 5/16" farther away from the mouth of the carb with small spacers, and longer screws.
Then I dug through some old kart parts boxes, and found a K&N 3" diameter filter that I had never used.
It took a piece of 1/2" thick plastic to adapt the K&N to the Echo.
I mounted the Atom igniton module in the carb area because there wasn't much room for it under the flywheel.
Then I attacked the stock muffler.
First, I ground over hanging weld bead out of the flange.
Then drilled holes in the inner bafflel, reshapped some of the baffels to aid flow, and hammered a dome into the cover to increase volume inside the muffler.
(20/20 hind sight, I could have gained more volume by just replacing the cover with a flat piece, and longer screws & spacers)
But my plans are to eventually put a tuned pipe on it, and looking through eBay under 'pocket bike' and Zenoah (RC boat engine),
I came up with quite a few for under $50, some made from stainless steel.
Anyway, it's together, and really screams.
How much better does it cut than a stock 30cc Echo ?
No idea, never had a good stock one.
Total cost of parts: About $200 before getting a tuned pipe.
Yes, I could have probably bought a good used mini-saw for that much, but it would have not been as fun
