Topic: New to me CB550 engine

[saxamaphone]

Hi guys, I was visiting my uncle recently and he said "Hey, don't you like old Hondas?  My neighbour has an engine for you." 

It was stuck so I started tearing it down.  I'll have plenty of engine spare parts now hopefully. 

Check these cylinders.  The rusty one is the one that's stuck.  Still can't get the cylinders off yet so letting it soak a bit more.











One thing I noticed while tearing it down was that the little metal tabs on the advance unit are broken so the bolt on the crank can just turn over.  Is that reparable?  Doesn't seem like it would be unless you welded them so the advance unit is probably garbage.

Forgot to add the engine number is CB550E - 1090428 so looks like a K2.

[calj737]

If you're attempting to rotate the motor, especially if it's seized, from the points side of the crank, DONT. Use the stator side bolt. Yes, it's much smaller, but it is much stronger (as you've just discovered).

I can tell you from current experience with another seized 500 motor, patience, penetrating fluid, fire, and muscles are about the only thing that's going to free those cylinders. There are many fluids and methods for releasing them, but I used Kerosene and filled the cylinders, lit it afire, then kept adding more to keep the flames going for about 2 hours on and off.

If that's unavailable to you, you can also use SeaFoam as a flammable. It's pretty safe and burns well. It will burn off, so adding more is required. If fire is not your thing, try MEK from the Home Center. It's a very aggressive "solvent and stripper". Very aggressive. Use protective gear, but it works really well.

But stay off that points side bolt...

[Duanob]

If you're attempting to rotate the motor, especially if it's seized, from the points side of the crank, DONT.

Sounds like someone else already tried that, it's a bit too late.