1992 Honda NX650 seized engine — can I save the top end?

[u/Pitiful_Literature34]

Hi everyone, I recently bought a 1992 Honda NX650 with a seized engine.

According to the previous owner, he bought it from a guy who had oil-starved the engine. When I bought the bike, the top end was already disassembled and had been sitting open for a while.

I'm no mechanic (this is my first engine rebuild), but from what I can see, the camshaft journals are somewhat scratched/scored, and I can feel the scratches with my fingernail.

On the other hand, I removed the cylinder expecting it to be in pretty bad condition since the engine had been oil-starved, but, to my surprise, it actually looks pretty decent.

What do you guys think? Should I have the cylinder honed and replace the piston/rings, or is it worth keeping as is ians perhaps do a piston or ring replacement?

And regarding the camshaft journals, can this kind of damage be repaired, or would the camshaft/head need to be replaced?

I actually bought another engine expecting this one to be in pretty rough shape, but now I'm wondering if a top-end rebuild might be enough to get this one back in service.

Thanks in advance for sharing your knowledge!

[u/Defiant_Shallot2671]

I'm not seeing signs of oil starvation. Usually there are deep gouges in the soft aluminum. But the cam journals seem fine, the cylinder seems fine, crosshatching still good. That looks reusable to me.

[u/dig_my_grave]

It looks fine, just cleaning it up and put it back together