Hey guys, I've read several threads about problems with 128LDs, but none of them quite match what I've got going on.
To begin with, this was given to me by a friend who had given up on it a couple of years ago. He said it was surging and wouldn't run right.
When I got it, it had been sitting for several years, was dirty, and had broken fuel lines and crap in the tank.
I cleaned it all up, blew everything out, and installed one of those cheap carburetor kits from Amazon, including new carburetor, fuel lines, fuel filter, air filter, gaskets, and spark plug (Savior BPM7E).
The engine pops off readily with the choke on, then at half-choke it will sometimes start and run for a bit, but if I try to open the choke or give it more than just a touch of gas, it just dies.
I removed the spark screen and it looked good, but tried to run it without it, no joy.
Looking into the cylinder through the exhaust port and the spark plug hole, there appeared to be some vertical scoring, but compression felt pretty good on the pull-rope.
Holding the pull-rope and letting the machine dangle, with a half-tank of gas, it will work its way down if I jiggle it a little, but it doesn't just drop.
After trying adjusting the carburetor, starting at 1.25 turns out from seated, same result. Seems to start between 1.25 and 1.5 turns out on both screws, but just a little change on the Low side while running, kills it.
I bought an Amazon compression tester and it reads between 15lbs and 20lbs on this machine and the same on a smaller Echo that runs fine (well, it doesn't quite get up to the RPM I think it should, but it starts and runs), so I'm convinced the compression tester is a piece of crap.
I pulled the jug off of it, and cleaned it up some. There was some carbon and staining on the sides of the piston, with a thick layer of carbon on the top of the piston. I cleaned it all up with a green Scotch Brite pad, removed the ring and cleaned it's slot, then put it all back together, making sure the gaskets and mating area were all clean and flat.
Had a little better luck getting it to keep running on half-choke after that, but still not really running. Never runs more than a minute or two, and usually less than that.
I pulled the new carburetor and used its parts to rebuild the old carburetor, after a good cleaning -- it was a real mess.
That seems to run just a bit better, but not at all good.
The really weird thing I notice is that when I do get it running (which is pretty iffy), it doesn't idle smoothly. It will ramp up like the trigger's being pulled. It has gotten to pretty high RPM, then drops back down, might speed up a little, then slow down, then just die. It really acts like someone is feathering the throttle, but it's just sitting there on the bench.
BTW, the head spins up with the RPMs, and much of this testing has been done with the lower shaft removed. Everything seems to spin freely.
Wife's in town now, going to bring me a new spark plug, as I'm running out of things to try.
Any ideas? I'm particularly confused by the idle speed increasing and decreasing significantly with no input. I don't understand that, but it did it with the new and the old carburetors.
I really need to get this thing working before the weeds swallow us up.
Hoping someone has a silver bullet to cure this mess.
Thanks.
To begin with, this was given to me by a friend who had given up on it a couple of years ago. He said it was surging and wouldn't run right.
When I got it, it had been sitting for several years, was dirty, and had broken fuel lines and crap in the tank.
I cleaned it all up, blew everything out, and installed one of those cheap carburetor kits from Amazon, including new carburetor, fuel lines, fuel filter, air filter, gaskets, and spark plug (Savior BPM7E).
The engine pops off readily with the choke on, then at half-choke it will sometimes start and run for a bit, but if I try to open the choke or give it more than just a touch of gas, it just dies.
I removed the spark screen and it looked good, but tried to run it without it, no joy.
Looking into the cylinder through the exhaust port and the spark plug hole, there appeared to be some vertical scoring, but compression felt pretty good on the pull-rope.
Holding the pull-rope and letting the machine dangle, with a half-tank of gas, it will work its way down if I jiggle it a little, but it doesn't just drop.
After trying adjusting the carburetor, starting at 1.25 turns out from seated, same result. Seems to start between 1.25 and 1.5 turns out on both screws, but just a little change on the Low side while running, kills it.
I bought an Amazon compression tester and it reads between 15lbs and 20lbs on this machine and the same on a smaller Echo that runs fine (well, it doesn't quite get up to the RPM I think it should, but it starts and runs), so I'm convinced the compression tester is a piece of crap.
I pulled the jug off of it, and cleaned it up some. There was some carbon and staining on the sides of the piston, with a thick layer of carbon on the top of the piston. I cleaned it all up with a green Scotch Brite pad, removed the ring and cleaned it's slot, then put it all back together, making sure the gaskets and mating area were all clean and flat.
Had a little better luck getting it to keep running on half-choke after that, but still not really running. Never runs more than a minute or two, and usually less than that.
I pulled the new carburetor and used its parts to rebuild the old carburetor, after a good cleaning -- it was a real mess.
That seems to run just a bit better, but not at all good.
The really weird thing I notice is that when I do get it running (which is pretty iffy), it doesn't idle smoothly. It will ramp up like the trigger's being pulled. It has gotten to pretty high RPM, then drops back down, might speed up a little, then slow down, then just die. It really acts like someone is feathering the throttle, but it's just sitting there on the bench.
BTW, the head spins up with the RPMs, and much of this testing has been done with the lower shaft removed. Everything seems to spin freely.
Wife's in town now, going to bring me a new spark plug, as I'm running out of things to try.
Any ideas? I'm particularly confused by the idle speed increasing and decreasing significantly with no input. I don't understand that, but it did it with the new and the old carburetors.
I really need to get this thing working before the weeds swallow us up.
Hoping someone has a silver bullet to cure this mess.
Thanks.