Solved Cox 0.049 Golden Bee Disassembly

Citabria

Active member
During the process of trying to remove the glow head I put my wrench in the exhaust ports. I guess I screwed up the cylinder because now the piston won’t move as freely as it did before. It’s like it’s half way seized up. How do I do properly disassemble it?
 

quorneng

Master member
Citabria
Sorry but if you have indeed distorted the cylinder I fear your Golden Bee is now wrecked unless you can find a replacement cylinder.
Cox engines are delicate and after a really long period the threads get gummed up solid.
Soaking in paraffin for long periods and the gentle application of heat should eventually allow disassembly using forces lower enough that will not damage anything.
 

Citabria

Active member
Citabria
Sorry but if you have indeed distorted the cylinder I fear your Golden Bee is now wrecked unless you can find a replacement cylinder.
Cox engines are delicate and after a really long period the threads get gummed up solid.
Soaking in paraffin for long periods and the gentle application of heat should eventually allow disassembly using forces lower enough that will not damage anything.
Yeah I found a replacement cylinder and piston but slowly over time it got better and better I just ran glow fuel through it
 

Piotrsko

Master member
You can deburr the cylinder after you get it apart. It will oversize for the piston and result in lower compression and fuel intake and thus lower power. In other words it will spin a 6-3 prop instead of a 6-4 @ a given rpm target

No it didn't get better and better, it will eventually wear out such that it won't start. You are using higher nitromethane percentage fuels, typically labeled racing or helicopter.
 

Citabria

Active member
You can deburr the cylinder after you get it apart. It will oversize for the piston and result in lower compression and fuel intake and thus lower power. In other words it will spin a 6-3 prop instead of a 6-4 @ a given rpm target
I just plan on buying a new piston and cylinder the original had sub induction I already ported the intake so with the double slit piston and cylinder I should have black widow performance.
 

Piotrsko

Master member
Shave the head aka glowplug. If you ported it, this is easy so I wont explain. Does cause the piston pin to detach and a hole to occur in the piston, but you can get to 8-4 for prop. Equivalent to an 09. Black widows just had better fitting parts, wasn't that special except the tank had a 5 minute run and supported inverted. The parts place said they had .051 cylinder assemblies
 

Citabria

Active member
Shave the head aka glowplug. If you ported it, this is easy so I wont explain. Does cause the piston pin to detach and a hole to occur in the piston, but you can get to 8-4 for prop. Equivalent to an 09. Black widows just had better fitting parts, wasn't that special except the tank had a 5 minute run and supported inverted. The parts place said they had .051 cylinder assemblies
Ok thanks!!