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Main Area => General GS500 Discussion => Topic started by: bmf on June 16, 2013, 06:14:46 AM

Title: Is this piston Slap?? (short video)
Post by: bmf on June 16, 2013, 06:14:46 AM
Hi Folks,

And hello, new to the forum!

I think my gs500 has piston slap.

Here is a short video of the sound (note its 4 meg)

https://www.dropbox.com/s/f7qqp9lcsebbuar/IMG_1475.wmv

Can anyone confirm?

thanks

Brett


Title: Re: Is this piston Slap?? (short video)
Post by: Soloratov on June 16, 2013, 07:31:57 AM
While it has a very distinct interval, I would imagine piston issues would be extremely consistent and a lot closer together to time with each stroke. For a moment when you had the camera on the right side cover, it seemed to be louder down in the case.
Title: Re: Is this piston Slap?? (short video)
Post by: gsJack on June 16, 2013, 07:56:03 AM
Doesn't sound like it to me, with 98.5k miles on the clock I can hear the jugs rattling now when coming back hot from a ride and passing slowly along a long line of garages.  Still think it will make the 100k mile mark this summer.   :icon_lol:  Like Soloratov said it makes a much higher frequency noise than yours.
Title: Re: Is this piston Slap?? (short video)
Post by: bombsquad83 on June 16, 2013, 08:16:27 AM
Mine makes this sound after it's nice and hot.  I believe it's the camshaft end-play issue.  It's harmless.
Title: Re: Is this piston Slap?? (short video)
Post by: sledge on June 16, 2013, 01:22:42 PM
Let the bike tick over, lift the plug cap on the cylinder you suspect is slapping........if the noise goes away then yeah........its slap.

However yours isn't slapping, as mentioned........ its camshaft float and a very good example too  :thumb:
Title: Re: Is this piston Slap?? (short video)
Post by: bombsquad83 on June 16, 2013, 01:42:09 PM
Makes me feel better as well to hear confirmation that sound is camshaft float :).  What is piston slap anyway?
Title: Re: Is this piston Slap?? (short video)
Post by: bmf on June 16, 2013, 02:39:55 PM
Thanks a million everyone!
Title: Re: Is this piston Slap?? (short video)
Post by: gsJack on June 16, 2013, 03:03:18 PM
Seems we're 4-0 on it not being piston slap but it's only 2-1 on it being cam knock.  :icon_lol:  I just don't hear cam knock on that vid and I've listened several times.  I've had cam knock on both my 97 and 02 GSs at various times.  The intermittent noise I hear on the vid is more like a tick noise while the cam knock is a deep thud like noise.  It knocks only at idle and only when hot.  Pick it up to a fast idle and it stops.  bmf could confirm by pulling the valve cover and seeing if one of the camshafts (unloaded with lobes turned away from tappets) has an excessive amount of sideplay.
Title: Re: Is this piston Slap?? (short video)
Post by: piresito on June 16, 2013, 04:36:26 PM
Cam end float thingy +1!
Makes 3-1.

I was in your position some time ago, when GSjack heard my video and also suggested it was the cam end float noise. Maybe you video has some distinct harmonics than mine, althought I can recognize that noise, and 100% sure that's the same noise my first GS had, and now my second GS does it the same way.

No harm, just a nice distinct feature. :D
Title: Re: Is this piston Slap?? (short video)
Post by: twinrat on June 17, 2013, 12:29:18 AM
That is clearly a rythmic noise that seems to come and go in a set order. Like  say every  inlet opening on the left side as an example .R inlet valve R exhaust valve L inlet valve CLICK  L ex valve   R inlet valve R ex valve  L  inlet valve  CLICK  and so on get it . Maybe and just maybe you might have a valve with a very loose shim  say in excess of say .015 " or your timing chain is very worn in one particular link ,.it would help if people would put up the mileage of there vehicle they have a problem with so as to make diagnoses easier. Keep us all posted as mystery,s like this are  very challenging and interesting..
Title: Re: Is this piston Slap?? (short video)
Post by: Janx101 on June 17, 2013, 12:31:25 AM
 ;) ;) ;) i thought it was theme music!! .. like you know in an action movie when the good guys are sneaking up on the bad guys all stealthy like... da da dum .... tic-a-tic... da da dum .... tic-a-tic ...  :D ;) :thumb:
Title: Re: Is this piston Slap?? (short video)
Post by: sledge on June 17, 2013, 02:22:51 AM
Cam float noise is random, it comes and goes and doesn't necessarily follow the engines cycle. At tick over each cam is doing about 400rpm and each valve is opening and closing about 6.5 times per second, the rattle we can hear in the vid has a roughly 2 second cycle.

It just doesn't have the magnitude to be connected with a single valve  :dunno_black:
Title: Re: Is this piston Slap?? (short video)
Post by: piresito on June 17, 2013, 06:40:22 AM
BTW, in my case, if I lean the bike it disappears.
On bikes I had  (one had 11Kmiles) and the one I've got 18Kmiles. Both do it the same way.
Title: Re: Is this piston Slap?? (short video)
Post by: gsJack on June 17, 2013, 06:50:42 AM
Since all the other posters are less than half my age I'll retire my ageing ears from the debate and let you all decide it.  Maybe I don't hear what I think I hear.   :icon_lol:
Title: Re: Is this piston Slap?? (short video)
Post by: sledge on June 17, 2013, 08:08:29 AM
Here is a link to the famous service bulletin. Its not been up for a while so it will be new to a lot of people, apologies to those who have seen it many times before  :thumb:

http://everythinggsxr.com/wp-content/uploads/2012/06/asmc_004983.pdf (http://everythinggsxr.com/wp-content/uploads/2012/06/asmc_004983.pdf)
Title: Re: Is this piston Slap?? (short video)
Post by: Calpantera on June 17, 2013, 11:46:35 AM
To me it sounded like it was closer to the crankcase and not up in the head like cam walk would be..
Title: Re: Is this piston Slap?? (short video)
Post by: Janx101 on June 17, 2013, 02:52:14 PM
Quote from: gsJack on June 17, 2013, 06:50:42 AM
Since all the other posters are less than half my age I'll retire my ageing ears from the debate and let you all decide it.  Maybe I don't hear what I think I hear.   :icon_lol:

Ahh c'mon Jack , age before beauty and all that! .... Some of us younglings (like me!) ... Don't even know what we think we hear! ... So you a step ahead already!  :thumb:
Title: Re: Is this piston Slap?? (short video)
Post by: piresito on June 18, 2013, 02:13:51 AM
Quote from: Janx101 on June 17, 2013, 02:52:14 PM
Quote from: gsJack on June 17, 2013, 06:50:42 AM
Since all the other posters are less than half my age I'll retire my ageing ears from the debate and let you all decide it.  Maybe I don't hear what I think I hear.   :icon_lol:

Ahh c'mon Jack , age before beauty and all that! .... Some of us younglings (like me!) ... Don't even know what we think we hear! ... So you a step ahead already!  :thumb:

Yeah, if wasn't I would have probably spended big bucks to solve that harmless knock...
He keeps mentioning his age, but afterall, he is young enough to ride other bike than a Harley...  :icon_lol:
Title: Re: Is this piston Slap?? (short video)
Post by: bmf on June 21, 2013, 08:48:28 PM
Hi Folks, a quick update,

If I lean the bike left or right, the cam noise goes away, so it definitely seems to be that problem.

However, while running it in I noted once that the oil light flashed while idling. I measured and am only getting around 20 PSI at 3000 RPM instead of the 20 to 75 I am supposed to get.......

I plan to check the oil pump first before opening the crank case, but is there a way to check the pump, it seems to be a sealed unit? 

Thanks all

Brett
Title: Re: Is this piston Slap?? (short video)
Post by: piresito on June 22, 2013, 12:55:39 PM
You set the idle for which rpms?
What type of oil are you using, and does it have enough?
Remember to check it on center stand, and with the stick fully out, just sitting in the beggining of the threads...
Title: Re: Is this piston Slap?? (short video)
Post by: bmf on June 27, 2013, 08:19:56 PM
Hi Piresito,

Yes oil level is right , maybe slightly over max mark, currently with 20W50 oil, still very low pressure.

Waiting for my replacement pump to arrive.
Title: Re: Is this piston Slap?? (short video)
Post by: piresito on June 28, 2013, 09:41:06 AM
Isn't that oil too heavy for the GS500?
10W40 is recommended, some use 15w40, but 20W50 is a bit on the higher limit, isn't it?
Maybe the oil experts can drop here their opinion...I don't know shaZam! about oil weight vs pump pressure and how the oil pump works in the GS500!