Alternator didn't charge enough to keep the battery topped up, and then stopped charging completely after some wires shorted - the fault of the previous owner, who both fitted the wrong alternator for the cover, the wrong rectifier/regulator, and used poor connectors.
Fork seals leaking due to pitted forks; a result of old age and stone chips.
Trip meter reset knob came loose.
Wiring harness is a mess; also a result of the previous owner's ingenuity.
One carb overflowed twice.
Fuel petcock leaking a little in the OFF position, which goes poorly with a leaky carb.
Instrument lights not working anymore.
Several valves with no clearance.
Swingarm bearings not reamed, and operated with too much friction.
Rear brake pedal stuck, and was almost impossible to free and remove for lubrication.
One cover bolt broken in the starter motor.
Inner fender worn through for some reason.
Stripped threads on one of the triple clamps.
Several bolts were of the wrong type or missing or over/under-tightened.
Ignition switch botched, although workable.
Threads on lower front and lower rear engine mounts stripped.
Alternator cover cracked from a fall and drilled for wires from a non-stock alternator.
Wrong ignition plate fitted.
Seat lock missing, and seat fitted wrongly.
Engine has several very minor oil leaks; not enough to form drops, just a tiny speck of oil film here and there.
Engine stutters at times, especially at higher RPM and heavy load.
Now, that list must sound condemning, but really isn't. I bought two bikes for less than I would usually pay for one. And what was bad on one was mostly good on the other. So although it was a time consuming restoration, it wasn't costly. Also, the bike is very well made and intelligently laid out; one of the easiest bikes ever to wrench on.
I lifted the alternator and complete wiring harness from the parts bike, and soldered on new contacts and wires where needed.
The bike now has stock bolts throughout, apart from a few on the engine. The engine itself is from a newer F version with Hy-Vo cam chain and automatic tensioner. The engine has been opened at some point, and the mileage on the clock is highly unreliable. But since the engine runs fine, has good compression and uses little oil, the mileage is of little interest. Also, I have a spare with 22k miles / 35k km on it if this one breaks down.
The fuel tank and covers came with new, professional paint as part of the deal. A stock exhaust system also came with the parts bike, not mint, but pretty good. Front fender isn't stock - it came with one that looks like it could be from an LTD model and one from an old Z1. Since the former had the best chrome, it's what I fitted. The rear fender is in really good shape, and all chrome is from fair to good, and from two steps away, the bike looks almost new.
The seat on the parts bike was stock also; looked almost new, with all the stickers still in place. Same with the battery box and inner fender. I opened the speedo and tacho because the lenses were really dirty on the inside, as were the faces. Plus the redline had faded into pale peach, so I touched that up as well.
I didn't need a new ignition lock since the parts bike had a virtually new aftermarket one, but I managed to find a complete set, brand new OEM, that also included the seat lock I required. Nice to have just one key, although I decided to use the new tank lid fitted to one tank that requires its own key - stock lock has no pins and can be opened with a screwdriver. So I have two keys, but also added safety.
The stock rear shock absorbers on the parts bike cleaned up quite well - although I have later found another pair with spotless springs instead of the pitted ones on the pair I had, and I will mix and match the best parts over winter - and it works surprisingly well. Sure, there is a lack of rebound damping, but for casual riding they're OK.
I overfilled the fork with oil, because I didn't know the springs were supposed to be inserted during measurement. The result is that the bike, along with springs on max preload, rides much taller than stock. It's virtually impossible to touch down anything, the pegs riding very high off the ground. Well, after I sourced and fitted a centre stand, it will scrape fairly easily. With the front back at stock height, I suspect it must be cornered very gently.
After synchronizing the carbs and adjusting the hopelessly adjusted valves, the engine pulls from 1300 RPM in top gear and effortlessly before reaching 2000 RPM. It's a very flexible engine that feels much stronger than its 652cc would indicate, but on the other hand, it doesn't have lots of top end power. Still, for an elderly bike cruised on nice evenings, it is very relaxing not having to row the shifter constantly.
I'm running a 42T rear sprocket instead of the standard 45, but I think a 38 would be better. The engine can easily pull it, although one must be prepared to downshift often to 4th when cruising at elevated speed, and headwinds or hills are encountered. Taller gearing would make cruising relaxing, as the engine even now - with said 7% higher gearing than stock - is quite busy over 90 kph / 55 mph.
All known issues will be taken care of over winter. Once the bike is fully sorted - I have new OEM fork stanchions waiting to be fitted, a new-ish lower brake hose that will also go on, plus I'm going to fit a relay for the ignition coils - I expect it to provide many years of trouble free riding.
What I particularly like is how relaxing and comfortable the bike is to ride overall. The seating position is splendid for a bloke with sore knees. The seat is pretty well padded and easy to slide back and forth on to prevent butt burn. Handling is amazingly quick and nimble for a fairly heavy bike. Regardless, it makes me ride fairly slowly, which is a particularly good thing for someone who has crashed a bit too often. In addition, it also goes nicely together with my friends' old BSAs, Triumphs and Guzzis.