korider.com | Hyosung Motorcycle Owners Forum

korider.com | Hyosung Motorcycle Owners Forum

  • January 19, 2019, 09:38:42 AM
  • Welcome, Guest
Please login or register.

Login with username, password and session length
Advanced search

News:

Welcome to Korider.com!

Pages: [1]

Author Topic: Clunking at low rpms  (Read 800 times)

dcheripka

  • Goodbye chickenstrips!
  • ****
  • Offline Offline
  • Posts: 165
Clunking at low rpms
« on: July 19, 2014, 01:09:12 AM »

So recently I've noticed some clunking at low rpms coming from the motor. I have an 07 GT650R with 22000 miles. I'm just trying to figure out if its a warning or if its fairly normal. I had the valve clearance chk'd at about 18000 miles. She is running just fine.......
Logged

Register and log in and the Ads below will be gone! :D


umop-ǝpisdn

  • Global Moderator
  • Forum Addict
  • *****
  • Offline Offline
  • Posts: 7459
Re: Clunking at low rpms
« Reply #1 on: July 19, 2014, 03:08:39 AM »

In time with engine RPM?

Only happens with clutch pulled in?

High pitch, or low?

The usual suspects are cam chain tensioners or the clutch basket..
Logged
I used to be a sensitive, new age guy, but times have changed and now I am more of a caring, understanding, ninties type.

uiwnq22776

  • Training Wheels
  • *
  • Offline Offline
  • Posts: 23
Re: Clunking at low rpms
« Reply #2 on: July 19, 2014, 06:12:11 PM »

i have some clunking too as well as  my bike dying at low RPM, seems to be having a hard time idling.

from my research its clogged fuel injectors, but i am a newb.
Logged

dcheripka

  • Goodbye chickenstrips!
  • ****
  • Offline Offline
  • Posts: 165
Re: Clunking at low rpms
« Reply #3 on: July 20, 2014, 08:28:43 PM »

  notice it the most when starting from a stop. 1st and 2nd gear mostly but I've heard and felt it in higher gears at lower rpms as well. Nothing with the clutch pulled in. It seems like a rotating clunk if that makes sense from the sound of it........
Logged

umop-ǝpisdn

  • Global Moderator
  • Forum Addict
  • *****
  • Offline Offline
  • Posts: 7459
Re: Clunking at low rpms
« Reply #4 on: July 20, 2014, 11:00:23 PM »

dcheripka,

The description is a little sub-par.. :/ If it's only happening while changing gears, I would guesstimate that it involves the clutch, gearbox, or final drive (i.e. chain and sprockets).

I would suggest that you want to check the final drive, first, as that represents a risk to your safety if something were to break. Get the front sprocket cover off, it's the one that the chain disappears under at the rear of the left hand side of your bike. A simple process. Just undo the bolts and it pulls off, note that there is a metal tie that holds some wires on one of the top bolts. Don't lose it. A point of note. Under that cover is the foulest, most evil muck on the face of the earth. Wear stuff you don't mind getting dirty, because it WILL.

Once the cover is off, you want to check and make sure that the front sprocket nut has not come loose. That nut is very large, 32mm maybe? Most tool sets would not include such a large socket.

Also check for saw-toothing of the sprocket.



The tension on your chain should be such that the middle of your chain should be able to move 2cm (almost an inch) up and down. No less. SLIGHTLY more is OK, but only slightly. Caution on the no less part, I mean it. A snapped chain has a 50/50 chance of being shot harmlessly, out the back of your bike, or being fired forward and wrapping itself around your now missing left foot. Might be a good point to mention that the chain guard should be secure.

If all this checks out, then consider the clutch your most likely suspect.
Logged
I used to be a sensitive, new age guy, but times have changed and now I am more of a caring, understanding, ninties type.

dcheripka

  • Goodbye chickenstrips!
  • ****
  • Offline Offline
  • Posts: 165
Re: Clunking at low rpms
« Reply #5 on: August 02, 2014, 01:13:34 AM »

Update..........So I've had more time to try to figure this out.......Still no clue but it does seem to be getting worse. Heres what I can say. It seems to be coming from the left side of the motor. Nothing with the clutch pulled in and also it doesn't seem to be matching my rpm's. It only happens when Its in gear and moving and it seems to be a steady rotating clunking sound. If I'm moving and pull in the clutch there is no sound. Kinda rules out sprockets or clutch I'm thinking. A friend mentioned the alternator......Does this sound like a possible issue?
Logged

Hylife

  • I ride & I vote.
  • Forum Addict
  • *****
  • Offline Offline
  • Posts: 2635
Re: Clunking at low rpms
« Reply #6 on: August 02, 2014, 07:37:15 AM »

Quote
It only happens when Its in gear and moving and it seems to be a steady rotating clunking sound

Remove the cover over the chain front sprocket and check for a loose sprocket. Should have a large flat washer bent over the nut.
Logged
2011 GV250 - 2011 GV650C - It's not 'what' you ride, it's 'that' you ride.

umop-ǝpisdn

  • Global Moderator
  • Forum Addict
  • *****
  • Offline Offline
  • Posts: 7459
Re: Clunking at low rpms
« Reply #7 on: August 02, 2014, 10:24:04 AM »

Agree, you need to get that front sprocket cover off and get eyes on the chain and sprockets.

More on what Hylife said. There is a metal disc that functions as a locking mechanism for the nut that holds the front sprocket in place. The metal disc is designed to be bent over a flat side of the nut, to prevent the nut from being able to work itself loose.

Get the cover off and have a look. If you cannot identify the disc in question, then likely it's been removed and not replaced. This would represent a serious safety issue.
Logged
I used to be a sensitive, new age guy, but times have changed and now I am more of a caring, understanding, ninties type.

kenwalton86

  • Training Wheels
  • *
  • Offline Offline
  • Posts: 2
Re: Clunking at low rpms
« Reply #8 on: January 04, 2019, 12:27:35 AM »

Sorry to revive an old post, but I have this exact same issue, so was wondering what your end result was?
Low gears (1, 2 maybe 3) there is a tick/clunk from the front sprocket area, but when you hold the clutch in, there is absolutely no noise.
Haven't pulled anything apart yet to assess, just didn't want to go in blind.
Logged

Pages: [1]