what to check

I bought a '78 kz650c.

What basic things should I get checked or replace so I'm not broken down on the highway somewhere in the first few weeks? Here is the bike's history--
It's a barn find about 8 months ago, not working at the time. It has 22,000 miles on it. The shop I bought it from, which specializes in '70s Japanese bikes, did the following according to their ad:

-Brakes fully serviced; front caliper completely rebuilt, flushed, and bled.
-BRAND NEW oil change
-Brand new Dynatek Dyna S ignition system
-Carbs have been METICULOUSLY disassembled, ultra-sonic cleaned, and tuned!
-Chain fully cleaned, re-oiled, and tightened to spec.
-All electrical, lights, horn, etc work perfectly, as they should.
-BRAND NEW battery
-BRAND NEW fuel filters and lines
-BRAND NEW NGK spark plugs

I've met the owner and trust him so far, he has a warehouse full of '70s bikes. What else should I have checked, to be prudent? I'm thinking cables... ??

Replace your throttle cable, clutch cable, and the glass fuses. I overlooked both the first time around and both left me stranded on the side of the road.

Did they check/adjust the valves?
Carb synchronization checked?

How does it run? Are you experiencing any problems? Forks & suspension working well or leaky?
Tires?
Fuel filter clean?
Probably best to look in your manual for the periodic maintenance of closest mileage.

The guy who i'm buying it from's opinion on valves is if you don't hear them you're fine; you'll hear when you need a valve job. True?

I don't have it home yet but in the test drive I did there was no engine noise, smooth shifting, etc. I felt a slight wiggle feel in front and we're changing the tire in case the old one had a flat spot. If that doesn't help I'll have the the fork seals checked. Is there anything else that could cause a sorta loose wiggle feel while riding? Almost like I'm doing little tiny figure eights while just driving straight down the road.

When he was test driving the new tire today the bike died. With investigation it was a faulty ignition switch. These are the things I want to check and change in advance, just looking for a list before I take it home and I need objective suggestions (not the shop guy). thanks.

Definitely not true. Tight vavles will usually not cause much in the way of noise, however they will destroy your engine if gone unserviced. The front end wobble is probably either the fork seals or an unbalanced front tire.

Maybe some tapered roller bearings for the steering neck from All Balls
Dave

Absolutely not true about the valves. They need to be checked regularly. Typically, the lash gets smaller over time, finally leading to poor running and burned valves, not extra noise.

That wobble can be caused by bad tires, worn or improperly adjusted steering stem bearings or swingarm bearings. If the tires are more than five years old or are showing signs of cracking, they should be replaced.

No matter what, you should get a genuine Kawasaki factory service manual for that exact model, and some basic tools so you can perform ALL the routine maintenance. That way you can be confident that it was done properly.

The 650 is a good, fun, well built bike and will provide many happy adventures with just a little regular care.

I hate to say it, but the guy's comment about the valves is a big ole' red flag to me.
The valve clearance is kinda important & doing the check is easy. changing shims is more involved, but doable.
This is one of those things in which the only way to know for sure is to check them yourself. you can't tell by using your ears.
a guy could just as easily say he adjusted them & you'd have no way of knowing unless you verified it yourself.

Okay, you asked, so this is what your manual for the 1978 KZ650 says to do every 10k kilometers (6k miles):
It's not everything you may want to do but it's a good start..

Check, adjust brakes (C model has disc brakes, check calipers moving freely, grease pins)
Check, adjust clutch
Check, adjust carburetors (this may involve synchronizing, at least I did for peace of mind)
Check, adjust throttle cables
Check spokes and rim runout (you have a C model so you have alloy wheels so visual inspection)
Clean fuel system (inspect tank internally too)
Clean, set spark plug gaps
Check brake fluid level
Adjust camshaft chain
Check, adjust points, timing
Check valve clearance
Check steering play <- this may be cause of speed wobble
Tighten bolts and nuts
Check tire pressure and tread wear <- possible speed wobble cause
Check drive chain wear (observe sprocket teeth for "shark finning" - my term for worn out sprockets)
Clean air cleaner element (Change it every 6k miles)
Perform general lubrication (don't forget the grease nipple on swing arm, it's kinda' hidden)
Change engine oil
Change oil filter element
Lubricate drive chain
Check, adjust drive chain (how far back on adjustment span is it already?)
Check brake wear (disc brakes again, so visual pads, my rear pads were almost worn out at 17k miles)
Change fork oil <- possible cause of speed wobble you mentioned
Lubricate the timing advancer
Change brake fluid (every year or 6k mi)
Lubricate swing arm (every year or 6k mi)
Regrease wheel bearings (every 2 years or 12k mi)
Regrease speedo gear housing (every 2 yr or 12k mi)
Regrease brake camshaft (every 2 yr or 12k mi) - drum brake rear but you have a C so follow for disc brake maintenance.
Lubricate steering stem bearings (every 2 yr or 12k mi)

There's many other things to consider since the bike has been pulled out of long term hibernation. Things like check and clean all electrical connectors, contacts and roll the fuse links is one such example (battery disconnected is probably wise here). The gas tank inspection as it sat so long it may be oxidized and will F-up your carbs quickly if there is no fuel filter. The fork seals are probably in need of replacing just for age. Replace the tires as soon as you can if they're not new already (you only got two and don't want a blow out...ever). Clean the engine and carefully clean out any dirt from the cooling fins. Quad-zero steel wool is good for shining up chrome after a wash and dry. Lubricate the seat pins and latch.

Begin buying new parts - shim kit, wheel and steering bearings & gaskets for engine - cover gaskets that you'll want to replace when you check timing, valve lash etc. It's almost certain that the bearings are original and they're inexpensive so why not replace them during next maintenance cycle. Buy these things as your budget permits but do it sooner than later so you'll have them ready should a problem be discovered and this way you won't be "down" for a week+ waiting for a gasket...

I've done this twice since Feb this year. Once on my 550a (got it as a running bike) and once on my 650-C during restoration. Until you've done all these things (and a few other things, I've already forgotten) you won't know what's going on with your new bike if it should misbehave or develop any issues.

Good Luck and Let the Good Times Roll !

He's got a warehouse full of bikes and doesn't know about the valves? What else is he not telling you. All the above. I replaced my wheel bearings and the whole attitude of the bike changed.
Steve

Awesome! thank you for this, I appreciate your time to write it all out. It's what I needed.

I'm looking for a manual online as well. G

dur65geo wrote: The guy who i'm buying it from's opinion on valves is if you don't hear them you're fine; .

he is a moron.