New Owner, I Hope!

[adam2kgt]

Hey guys, I am going tomorrow to look at a 83 CB650, hopefully I will be bringing it home! Anything in particular to look for? I know the usual stuff, but any oddball stuff to check out before buying? It's a dirt cheap bike, so I'm sure I will have some work to do, which is no big deal. Also, I have a 650 Nighthawk engine that I picked up for a go kart project, but it's a chain drive engine, instead of a shaft drive. Is anything from it interchangeable with the 83? One last thing, what kind of fluid do I need to use to change the shaft drive fluid? Thanks in advance!

[flynavyj]

  Good luck picking up your bike. I've only had a NH for about 3 weeks now, the most recent problem i've encountered involves the starter, but i can't think of any good ways to check that right now. The bike had issues with the clutch hydraulic system, i ended up rebuilding my slave cylinder, while i'm sure the master cylinder would be happy with a redo also...So see if the clutch feels spongy, or won't build up any resistance. If you get to ride it, see how the clutch feels after the ride. Because of how corrosive hydrualic fluid is, leaks become evident because of the paint pealing off, it will look as though you used aircraft remover on a specific area of metal, and the paint will just brush off in your hand, that should show evidence of a leak, and if the guy knows nothing, might get you a couple $$ off. Besides that, i'd check for general leaks, engine, driveshaft, differential, Mine is leaking a little bit of oil from behind the alternator, but that seems to be about it now that the slave cylinder is redone (knocks on wood). Good luck.

[detdrbuzzard]

hello adam2kgt and  to NHF make sure its charging

[ariwhiteboy]

  to the forum!  Good luck with the potential purchase! 


Remember to take  for us!

[noahnsteph]

hello adam2kgt and   to NHF make sure its charging

+1

If it's not charging you should be able to talk him down quite a bit and still fix it for less than $200 most times. Bring a multimeter and see if the if the battery charge raises as you rev the motor past the 2500 RPM range.  The rectifier/regulators are known to be a weak spot on these bikes. It sure was on mine.

[adam2kgt]

Thanks all. I will have to see if I can find my multimeter and take it with me. My wife and I just moved about a month ago, and I think I may have left it in Arkansas with a buddy    I plan to flush the brakes and clutch as soon as I get it, or any bike for that matter. I also want to change the oil, do the seafoam oil flush, change oil again, change the driveline fluid, grease driveline, drain fuel and refill with known fresh, and seafoam the carbs. I'm an auto tech, so it's not too big of a deal.

[geemann]

to the NHF!

sounds like a fun project, good luck!

[adam2kgt]

Well, pending a vin check tomorrow, it's mine! It has some issues (fork seals blown, tires aren't great, controls need some work) but my biggest concern is a lack of firing on the left two cylinders. Bike is extremely weak at low rpm, once it's revved up to 4k or so you can take of and ride it, but it's way down on power. Two left exhaust pipes were barely warm after a quick spin down the street. But, if you pull the far left plug wire from the coil to check spark, engine won't start at all.  Any ideas? The top end of the motor on the left side also sounds a little noisy. Any ideas? Will any of the parts from a chain drive 650 NH motor swap over to this bike?

[ExTex]

The 1982 Nighthawk 650 was chain drive.  The engine was an old single overhead cam model
that differs significantly from the 1983+ engines that were a new dual overhead cam design.
My guess is no parts are the same... as far as parts that you might want to swap.... maybe coils ?

Speaking of which, the cylinders that don't fire may have coil, pick up coil or CDI problems.

There are 2 of each, 1 for each pair of cylinders.  A bad CDI can work but yield poor power.
Try swapping coils and then CDI boxes to see if the problem follows either swap.

Ride safely,
 

[adam2kgt]

Well, so much for that idea. I hoped the top ends were the same. Either way, I gotta get this bike figured out and running good. I plan to clean carbs and put new plugs in, then go from there. Hopefully that alone will clean it up.

[Munkey]

Since the left side cylinders are fired from different coils and pickups, I don't think this is a coil or pickup issue.

Could be as simple as bad plug wires or bad spark plugs. I'd start by replacing both on all cylinders. Also check for spark at the spark plug on the 2 cylinders that are not firing. May be a fuel issue and not electrical at all.

[adam2kgt]

Well, I own it! It checked out good, so I made the plunge. Pics will follow, once I get it cleaned up a bit. I gotta get a different exhaust, somebody pulled the baffles and it is kinda loud and really annoying. Plus I will be cleaning the carbs and doing plugs and wires immediately. Then tires, fork seals, new shocks, new steering head bearings, blah blah blah.

[Soupskin]

Congrats!

We like "before" pics too!

[adam2kgt]

Well crap. I got the bike running great ( it was cross wired and only running on 2 cylinders!), went for a quick test ride, made it a half mile, and it sputtered out and died. Wouldn't start back, ran battery down trying to start it.  Now for some investigating and carb cleaning!