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View Full Version : Strange sound comming from my Nighthawk???



Mavrick
08-29-2012, 02:25 PM
I own a Honda 450 nighthawk and have always noticed a strange knocking sound when up-shifting on the bike, the knocking is not in-time with anything turning in the engine or wheels, it's a slow "clunking" sound that's there after up-shifting until the RPM's get higher then it goes away until I up-shift again to the next gear (it's not there at-all when down-shifting). Any ideas from you bike experts out there......

FTA
08-29-2012, 02:30 PM
I own a Honda 450 nighthawk and have always noticed a strange knocking sound when up-shifting on the bike, the knocking is not in-time with anything turning in the engine or wheels, it's a slow "clunking" sound that's there after up-shifting until the RPM's get higher then it goes away until I up-shift again to the next gear (it's not there at-all when down-shifting). Any ideas from you bike experts out there......

is it coming from tranny or motor ...

if it is from tranny try shifting with no clutch see if it still clunks if not its clutch plate on the upshift not a huge deal

kijiji
08-29-2012, 02:30 PM
Dose it sound like its coming from the tranny ?

Mavrick
08-30-2012, 01:58 PM
is it coming from tranny or motor ...

if it is from tranny try shifting with no clutch see if it still clunks if not its clutch plate on the upshift not a huge deal


Dose it sound like its coming from the tranny ?

It's kinda hard to tell where it's comming from but I think it's comming from the trany, I can't get it to "clunk" when it's on the stand and I put it in gear, only happens when moving on the road. I will try shifting without the clutch today and see if it still does it.........

ignored ant
08-30-2012, 02:11 PM
Kinda sounds like a bent shifting fork in trans,Needs the RPM's to fully engage the gear mesh.

Mavrick
08-30-2012, 05:14 PM
Kinda sounds like a bent shifting fork in trans,Needs the RPM's to fully engage the gear mesh.

Sounds like that might be it, I don't know enough about bikes to be sure. Is there any kind of test I do to check if that's indeed the problem?

Terryl
08-30-2012, 05:36 PM
Yup, it's called the bathtub test, that is where you take apart the tranny in the bathtub, (you don't loose any parts that way) (your girlfriend, wife or mother may not like it) and take the shifting fork down to the parts store to compare it to the new one you may need.

One other test is if you can get a small magnetic probe (don't use a home made one, you may wind up removing the side covers or tranny) in through the tranny oil fill hole,(this way you don't have to take any side covers off) and see if you have a lot of very fine metal filings in the bottom of the tranny,(a small amount is nothing to worry about) this will tell you if you need to remove the tranny (or engine) for service.

Lots of small metal filings means you have excessive gear lash do to uneven wear from an improper seating of the gears, ( bent fork) the "thunk" noise are the gears fully meshing.(only under a heavy load)

Another way is to take it down to the bike shop and have them check it out for you, this will save the wear and tear on the bathtub, and keeps the significant other from using a baseball bat on you and your bike.

A word to some, take the carpet out of the living room, and use some plastic sheeting on the floor when rebuilding your bike, it saves on the cleanup.

Terryl
08-30-2012, 05:37 PM
One last thing, have you checked the tranny oil?

Mavrick
08-30-2012, 11:02 PM
One last thing, have you checked the tranny oil?

Tranny operates from the same oil as the engine, and all is well with that, no leaks or metal at the bottom of the pan when I changed the engine oil last.

Terryl
08-30-2012, 11:12 PM
How many miles on it, and what blend (if any) oil did you use?

Mavrick
08-31-2012, 02:30 PM
The bike only has about 15000 miles on it, I can't remeber exactly what blend of oil I used but I know it was the blend recomended in the owners manual.

Mavrick
08-31-2012, 02:33 PM
is it coming from tranny or motor ...

if it is from tranny try shifting with no clutch see if it still clunks if not its clutch plate on the upshift not a huge deal

Ok, tried shifting without the clutch and the "clunking" is still there. It happens in every gear but only upshifting, it never pops out of gear and there is never any problems getting it into any gear ?

ignored ant
08-31-2012, 02:34 PM
Have you changed it to check for metal filings ?

A good premium grade oil such as Castrol GTX always helps also.


Also if you could securely "block it off the ground",,So rear wheel is up,


You could check drive train with it running

FTA
08-31-2012, 02:46 PM
i jus spoke with a friend of mine he says that the clunking is kind of a normal honda thing .. 2 things he said to try is to bleed the clutch out and secondly bleed out oil and replace with wynthetic 10w 50 if it only does it when it is cold then try getting a master cylinder kit for the clutch ... it may or may not improve it i guess it is a normal honda thing!

Mavrick
08-31-2012, 05:45 PM
Have you changed it to check for metal filings ?

A good premium grade oil such as Castrol GTX always helps also.


Also if you could securely "block it off the ground",,So rear wheel is up,


You could check drive train with it running

Didn't find any filings the last time I changed the oil. I did put it on the centre-stand and ran it in gear (got it up to 3rd I think) and there was no "clunking" sounds. It seems it only makes the noise when there is a load put on the trany.......

Mavrick
08-31-2012, 05:50 PM
i jus spoke with a friend of mine he says that the clunking is kind of a normal honda thing .. 2 things he said to try is to bleed the clutch out and secondly bleed out oil and replace with wynthetic 10w 50 if it only does it when it is cold then try getting a master cylinder kit for the clutch ... it may or may not improve it i guess it is a normal honda thing!

It does it when it's hot or cold (every up-shift in every gear) but I will try the synthetic oil. I will have to figure out how to bleed the clutch......didn't know you could do that?

FTA
08-31-2012, 05:53 PM
if it only does it under load ... it might be the chain or the rear hub or sprocket jus saying but it is a normal honda thing

Mavrick
08-31-2012, 06:32 PM
if it only does it under load ... it might be the chain or the rear hub or sprocket jus saying but it is a normal honda thing

I was thinking the same thing, I took the side cover off and had a peek at the sprocket/chain and it was not worn at all, I thought maybe a tooth might be missing or the teeth wornout and the chain was skipping but all was good and tight. The sound is not comming from the rear of the bike (rear hub) , it's comming from right below me when on the bike and riding.

FTA
08-31-2012, 06:52 PM
ya try the synthetic and see what happens and blled the master and slave cyclinder for the oil and i am pretty sure you can bleed the clutch out change all fluids you can to synthetic.

iq180
09-01-2012, 01:37 AM
i had a honda 550/4 that did that and the man i got it from had put new gears on it, but it ended up being the chain was bad.

FTA
09-01-2012, 02:40 PM
i had a honda 550/4 that did that and the man i got it from had put new gears on it, but it ended up being the chain was bad.

i was thinking chain too even if it looks ok just swap it out you will only spend a couple bucks and hell its a new chain lol

Mavrick
09-01-2012, 04:24 PM
i had a honda 550/4 that did that and the man i got it from had put new gears on it, but it ended up being the chain was bad.


i was thinking chain too even if it looks ok just swap it out you will only spend a couple bucks and hell its a new chain lol

At first I thought the chain as-well, I tightened it.....loosened it.....oiled it.......ect, and there was no change in the sound that was coming from the trany area so I ruled it out. I would be shocked if the chain was the issue but thanks for the thought.