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Main Area => General GS500 Discussion => Topic started by: GSJames on September 09, 2005, 12:39:09 PM

Title: Help! Knocking noise from the engine!
Post by: GSJames on September 09, 2005, 12:39:09 PM
Hey all,

Over the past few days, I noticed that the front of the bike was making a bit of a knocking noise, but I ignored it because it was very slight.

Now, a few days later, it's more pronounced.  It occurs when I accelerate, not at idle, and the volume increases with the speed of the engine.  When I was riding it back, I'd come to a stop and idle, and the bike stalled a couple times for no reason it seemed.  The bike also doesn't seem to go the way it used to any more.  It makes a loud knocking noise when you give it gas.

I hope it's nothing critical like a bearing going. I *think* but am not sure though, that it's coming from the top end of the motor, right beneath the gas tank.
Title: Help! Knocking noise from the engine!
Post by: GSJames on September 09, 2005, 12:48:13 PM
Also, I looked it up and read a posting on camshaft endplay.  It doesn't sound like the example the guy posted though:

http://media.putfile.com/gsf_knock

In my case, it is regular with the engine and deeper sounding.

Maybe I should do a recording of it?
Title: Help! Knocking noise from the engine!
Post by: davipu on September 09, 2005, 12:54:24 PM
cam chain tentioner.
Title: Help! Knocking noise from the engine!
Post by: GSJames on September 09, 2005, 04:46:05 PM
Hmm any write-ups on the web about the procedure?  Can't find it on the site, and checked pantablo's and buh-buh-buh-burma (?) but no luck.  :(

I've got the service manual, but its written for a professional mechanic and I find it kinda vague.  :dunno:
Title: Help! Knocking noise from the engine!
Post by: Kerry on September 10, 2005, 09:52:07 AM
Pictures 10, 11 and 12 on Marc Duch's Adjusting the Valves (http://www.gstwin.com/adjust_valves.htm) page show how to get to / remove / replace the camchain tensioner.

Srinath has spoken in the past about "rewinding" the tensioner so it will apply more tension.

Others have talked about an aftermarket camchain tensioner that is manually adjusted (as opposed to the stock, automatic tensioner).

See this thread (http://gstwins.com/forum/viewtopic.php?t=13777) and this one (http://gstwins.com/forum/viewtopic.php?t=15118) for more info on both options.  The APE manual tensioner that silverfox mentions in the first thread is part number ST750GX (gasket number is EC377) on this page (http://gsxrzone.com/sprockets.html).

(http://gsxrzone.com/resources/tensioners/tensioner.jpg)

Also, in this thread (http://gstwins.com/forum/viewtopic.php?t=13701) Bob Broussard talks about a guy who sells the ~$51 part for ~$38 on eBay.

In this thread (http://gstwins.com/forum/viewtopic.php?t=12848) Manjul shows the APE tensioner installed on his bike.

For even MORE info, use the Search link at the top of this page.  I typed in "manual tensioner", clicked "Search for all terms", and got lots of good threads back.


Quote from: GSJameschecked [...] buh-buh-buh-burma (?) but no luck
PS - My website domain name (bbburma.net) comes from a nickname I got from the schoolbus crowd back in junior high.  My last name is Burton, but a couple bozos "changed" it to "Burma" before I ever started riding the bus.  My two older brothers were dubbed "Big Burma" and "Little Burma", so when I joined the group I was automatically "Baby Burma".  Don't ask me why we decided to use the name among ourselves... :dunno:

Anyway, bbburma = Baby Burma.  Get it?
Title: Rewind
Post by: The Buddha on September 10, 2005, 11:54:26 AM
The Gs isn't the ideal candidate for the manual tensioner ... my eli's, the KZ, the Vulcan etc are all good ... just not the GS. The GS tensioner is very much re-windeable and its a decent tensioner to start with ... Kawi's came with total crap ... so makes sense to go manual ... and they are on the outside of the motor ... not in the middle ... in reality I'd adjust it when running and hot ... else you run the risk of over tightening it ... and that is impossible to do when the GS. I did it on my friends GS waaay back in 1996 and decided I wasn't going to convert over.
Cool.
Srinath.
Title: Help! Knocking noise from the engine!
Post by: Frost on September 10, 2005, 03:36:11 PM
how often do you have to adjust the cam tension?
Title: Help! Knocking noise from the engine!
Post by: GSJames on September 11, 2005, 11:15:34 AM
Thanks Kerry.  And I get the reference now.  :lol:
Title: Help! Knocking noise from the engine!
Post by: dgyver on September 11, 2005, 07:22:59 PM
Quote from: Frosthow often do you have to adjust the cam tension?
With a stock automatic tensioner, never.

Manual tensioners are best suited for built race engines. They constantly need to be checked for adjustment. Auto tensioners have been known to fail under heavy decel with high lift cams.


Anyway, back to your issue....

When is the last time you adjusted the valves?
Does the sound change as the bike warms up?
Title: Help! Knocking noise from the engine!
Post by: GSJames on September 12, 2005, 12:21:16 AM
Quote from: dgyver
Anyway, back to your issue....

When is the last time you adjusted the valves?
Does the sound change as the bike warms up?

Never adjusted the valves.  I've probably gone only about 1250 kms on the bike since I got it.  

Sound's always there, cold or warm.  I've got another thread, where I'm going at the carbs, thinking it's due to a lean cylinder:

http://www.gstwins.com/forum/viewtopic.php?t=20855