Attempt to revive first, or start with dismantling anyway?

[ST1100]

Hi,

how do you approach an old bike refurbishment:
Do a brief carb job, check valves and points and see if it even fires up, or simply knock the case apart for bottom and top end rebuild by default, since its unclear if and how a PO repair attempt might have caused havoc inside?

[totty]

I'd attempt to revive first, but I'd add a couple of steps -
turn it over by hand
tun it over without ignition until there's oil pressure and oil at the head

Then try to start it.

[ST1100]

Turning over by hand already done...
Both engines are "free" (kinda amazing by their pitiful visual appearance...), valves "puffing"... 

In total I have 4 carb banks (for 2 bikes ) around here, will attach the best/cleanest looking one for the trial...

[Bullit]

I asked myself the same question when I picked up my bike.
I turned the engine over by hand and left it at that deciding to do the rest of the bike first then tackle the motor.
My thinking was if I hit rough times and had to sell it then it wouldn't look like an old dog as most people are initially drawn in by looks

[ST1100]

One phrase here says to never knock a running engine apart... they won't get better from it

OTOH are there wear parts to address, like timing chain tensioners...
Honing and rings should be inspected... (OK, I've an endoscope avail...)
Out-drive bearings could have suffered...

OTOH-II is an engine rebuild one of the most complicated and expensive tasks... (just waded through the w/shop manuals... those SOHCs are quite complicated critters with zillions of parts to consider...)

[matthewmosse]

On my bikes I get them up and running, preffereably put some miles on them if not too far gone and that way you get a good feel for what - if anything needs doing inside the engine, often a really good thrashing gets it running right, I had one that leaked from the crank seals badly when first put in the bike, not having time for a couple of weeks to swap engines I just resolved to keep the oil topped up, the leak got less then cured itself, another engine one of the valves got hot first trip out, that one will get a proper rebuild of the head, it was also sticky shifting gear though everything looked ok so that will get looked at closely.