I have a CD-12 that I am working on and have a few problems to figure out. One of them that I think is serious is the way the spark advance mechanism shakes rapidly back and forth at low throttle. I took the flywheel off and smoothed out the edges with some sand paper in case maybe it was catching on some burs, but that might not be what's causing it. It didn't fix it anyway.
This is a short video of what it is doing. I'll try to lower the throttle to fine tune the low speed jet, but then it starts this shaking and dies.
The low and high speed jets both seem a little loose, like they can both wobble a little, and I don't they are supposed to. I might see if I have some more of the packing rings left over and get them tightened up. If they are able to suck air, could that be what is making the spark advance wobble at low throttle?
Another issue I need to solve is the leaking pressure tank. I think I'm just going to convert it to normal fuel pump. I rebuilt the entire tank and it still leaks like crazy if there's any pressure in it, even from sunlight induced heat expansion. Right now I have an old mower tank on a shelf up high gravity feeding while the motor is in a drum.
The engine got hot enough to boil water in just a minute of running it, so I don't think it's circulating water anymore. I'm pretty sure it was in the past, because it never got boiling hot like this before and I've had it out on the lake. As far as I know, there's no tell-tale, so I'll have to investigate.
This is a short video of what it is doing. I'll try to lower the throttle to fine tune the low speed jet, but then it starts this shaking and dies.
The low and high speed jets both seem a little loose, like they can both wobble a little, and I don't they are supposed to. I might see if I have some more of the packing rings left over and get them tightened up. If they are able to suck air, could that be what is making the spark advance wobble at low throttle?
Another issue I need to solve is the leaking pressure tank. I think I'm just going to convert it to normal fuel pump. I rebuilt the entire tank and it still leaks like crazy if there's any pressure in it, even from sunlight induced heat expansion. Right now I have an old mower tank on a shelf up high gravity feeding while the motor is in a drum.
The engine got hot enough to boil water in just a minute of running it, so I don't think it's circulating water anymore. I'm pretty sure it was in the past, because it never got boiling hot like this before and I've had it out on the lake. As far as I know, there's no tell-tale, so I'll have to investigate.