1984 nh 650

Discussion in 'Mechanical & Technical' started by Gingerilla, Jun 27, 2011.


  1. I just bought a nighthawk 650 yesterday and it needs the cam chain/ spring replaced, anybody do this before??
     
  2. Really need help i cant stand this noise!!! It has gotten worse now so i am checking for junk in the oil since my oil light is on now
     
    #2 Gingerilla, Jun 27, 2011
    Last edited: Jun 27, 2011
  3. Big T

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    You bought a 37 yr old bike and expected it wouldn't have problems?

    The cam chain tensioner is stuck

    Take it off ,take it apart,clean it and replace any seals

    Or, buy a new one if available

    You do have a service manual???

    And, quit riding it before you destroy the motor

    If it's too far gone now, you'll have to tear down the entire motor and replace the cam chain and guides
     
  4. ok, well the cam chain looks good but apparently this is a different noise now, might end up bein expensive, but it could be a range of tings from tappets to a cyclinder hitting the valves according to the guys on the nighthawk forum, should i take it to a pro like allens cycle, they always do goo work for me or investigate it myself???
     
  5. The minute i heard this noise i put it on the center stand and tossed out riding plans for a while
     
  6. What does the noise sound like? Is it a rattle? A click?

    I've owned 2 Nighthawk 650's so I have some experience with them. It's possible that the noise is "normal". In my experience Honda engines tend to have excess engine noise, so without actually hearing the noise it's possible that everything is normal (especially considering that the cam chain is in good form, as you say).
     
  7. SatansPetFerret

    SatansPetFerret Evil Genius

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    Just based on your posts here, it sounds like you may be in over your head and you may want to take to a shop for a diagnosis.

    Is the noise coming from the top of the motor? (Valves/cams etc)
    How many miles on the bike?
    What sort of shape is it in?
    Have you changed the oil/filter just to check if there's any metal pieces floating around in it?
     
  8. Yeah, to me it seems like it is comin from the top, it isnt nearly as loud at the base of the motor it has 19441 minles on the bike, And it is in good shape i have more pics of it on photobucket. And i did change the oil filter and oil as my first action, didnt take the filter apart to look for metal though. here is what it sounds like http://www.youtube.com/watch?v=fij4Nkmvmzw
     
  9. Ok that is not normal. lol.

    As far as what specifically it could be is hard to say. If you don't want to take it in to the shop, you could try the screwdriver trick to try and track down where the noise is coming from. (take a hard plastic handled screw driver and press the tip against a part you want to check, then press your ear to the handle)
     
  10. TREX 600

    1. Woods Coffee Riders

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    If you find the problem and need parts check out www.cheapcycleparts.com Have
    delt with them before on my vintage dirt bike.
    Hard to tell where the noise is. I agree with using the screw driver. I have done
    that trick for years and generally can pin point where the noise is from.
     
  11. I will try the screwdriver trick, it looks like from the guys on the nighthawk forum i will have to replace the crank and one of the piston bearings, so from what they told all the bearings have been discontinued so they will be a bitch to get, i will try and narrow where it is comin from
     
  12. You don't "need" to replace items with OEM, it's just easier. As long as you can find out the ID, OD, and thickness of the bearing you can often find one elsewhere online.
     
  13. Ok so i did the screw driver trick and it sounds the loudest by the rear right hand side of the valve cover, just a couple inches lower than the cover by the third cylinder
     
  14. Yeah i was thinkin i might need to find a guy that does cnc machining and get some made, the only prob is they had 5 different bearing sizes so when i get the rod out and the crank i can cross reference them to see what bearing i need
     
  15. TREX 600

    1. Woods Coffee Riders

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    Location:
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    I Ride:
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    Be sure to look at cheapcycleparts as they have both oem and after market.
     
  16. ok i will definately checkout their site. Dont know how i forgot to mention this also but i was on my way home and forgot to turn the gas line on, so it stalled then i turned it on and i has been doin this since that this happened like a .25 mile away from my house, that is also when the oil light came on, rookie mistake:oops::oops: but could it be the cause of this sound???
     
  17. RedKat600

    RedKat600 Vintage Screwball
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    Gas off? No.....oil light on, oh yes. You may have bigger problems if the oil light was on.

    Never, ever, ever run with the oil light on. Stop immediately.
     
  18. Agreed. Oil light on means stop and add oil. On older bikes the oil light typically means that there is 0psi in the oil system.

    After listening to the video several times I wonder if your starter gear got stuck/cannonballed? It's an unlikely occurrence, but the clicking doesn't seem to kick in until you let off the starter.

    However, if the oil light is still on after changing the filter and adding the proper amount of oil then you are looking at a broken oil pump.
     
  19. RedKat600

    RedKat600 Vintage Screwball
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    Have to disagree with this. I actually watched the vid this time, and that clacking noise sounds like a nuked big end bearing. Big end bearings are where the connecting rod attaches to the crank. It's either that or you have a fried wristpin where the rod connects to the piston.

    From your other post about noise from the cylinder, I'm guessing a wristpin. Really hard to say not being there. By chance have you pulled the #3 spark plug and made sure it's all there with nothing broken off? Drained the oil and looked for metal?
     
  20. Having watched the vid a few times... I'm inclined to think you should stop running that motor and just start dissecting it. That noise sounds expensive. The sound seems about right for a wanked bearing.
     
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