1984 Honda CB700SC Nighthawk S just whirs,no start!

[JunqueMale7]

Have seen problems with Synthetic oil being too slippery to engage the rollers in the starter clutch. If it is freshly full of synthetic oil, change it back to a standard oil like GTX 10/40 or GTX 20/50 and try it again. Bump start it if you have to to get the oil sloshed through the engine and it should be fine... IF the starter drive chain is not broken. While breakage does happen it is not that common on Honda's of that vintage.

[alexsuchapimp]

Sounds like it has a busted starter chain

[gorelord187]

ahhhh thats the day my best friend was killed in IRAQ oct 17 2008 and his parents gave me this same bike. honda 700s nighthwack starer more than likyly

[vidonthebox]

Starter chain is broken. common on nighthawks.

[charliemor3]

Hi

Well I'm glad you found the trouble; and, you weren't depending on me to fix it.

Glad you did find the problem though, good riding!!!!!!!

[kitemaniak80]

startrelet i had the same problem i have now a start relet from a kawazaky

[dariodiez]

Alternator chain broken.....

[mackiewizard]

If the generator does not provide charge to your battery, then I tell you you main bottom chain is broken. That chain links the starter-electric generator and crankshaft in a loop. Your chain is broken and is laying down at the bottom of the motor. My two separate Nighthawks chains have broken in that way. The motor has to be pulled out and crank lifted to insert a new chain. While at it, you may add new tensioners and maybe a top chain too + tensioner. I have done that to my first bike.

[mackiewizard]

To see if your generator provide current to your battery, you have to try push starting the bike. Once you have done that, look at the headlight beam strenght while you rev the motor, if the headlight stream stay unchanged, it means your generator is not linked to the chain. Broken starter-generator-crankshaft linking chain. Excellent bike but this an unfortunate common problem. Both my bikes did that. My original one now has 185 000KMs after I got a new chain at 105 000KMS

[mackiewizard]

If your generator works then the only other possibility would be a starter clutch failure but I have never heard any Nighthawk S owners since since I bought my first in 93 to have had this problem. Good luck. If you intend to keep the bike, I say it is a good investment to fix it. By lifting the crank, we saw I had the crankshaft seats wearing out a bit so it was a blessing in disguise for me that I had to open it up. I rode it to Inuvik, N-W Territories and Happy-Valley Goose Bay, Labrador sinc

[oceansaccount]

Seems to be leaning toward a starter chain issue? Or other starter issue possibly. Will be taking the starter out, and trying it as suggested to see if it turns one way, or both directions which may mean replacing.

[charliemor3]

Hi,

My mechanical experience is centered on cars. That is the sound a car makes when the solenoid is not engaging, which lets the starter turn free. Disconnect the battery, remove the starter, reconnect the batt; with the starter wired up, hit the start switch. If the solenoid engages, either it's too dirty to work in place or the spring is too weak to work in place. If it doesn't, check the circuits between start button and the starter. You may need to replace the solenoid or the whole unit.

[aguiristante]

No solenoid on these bike. it s a one way clutch.