1983 650 Front End Shake

[pwhite81]

Looking for advice guys.  1983 Nighthawk 650.  At speeds of about 85 or more the front end wants to tank slap.  NOT FUN!!  Any ideas?  Thought maybe it was because the front fork seals were shot.  Changed those.....didn't work.  Was told that usually happens because the rake on the front end is not enough.  The bike is all stock.  Open to any thoughts.  Thanks guys!

[JordanA]

wheel or steering head bearings, perhaps.  I would say the rear wheel might be out of alignment, but it's a 650 so I don't see that as likely.


Tires out of balance or not inflated properly?

[Zugzug]

Improper amount of fluid in the forks, unequal amount of air in each fork, forks not even in the tripple tree, cracked fork stablizer, tire/wheel out of balance or uneven wear pattern, too much freeplay in front axle, the tripple tree is too loose or bad bearings. If one of the forks have been replaced one of the springs could be weaker than the other and could cause the same symptoms.

Start with the easy/simple stuff first.