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Main Area => General GS500 Discussion => Topic started by: El motociclista on November 23, 2009, 12:36:11 AM

Title: Orientation of cam lobes when doing valve clearance checks...
Post by: El motociclista on November 23, 2009, 12:36:11 AM
I was reading through some older posts regarding checking valve clearances and came across this from GS Jack (see red highlight):

Quote from: gsJack on September 04, 2009, 08:08:31 AM
Lots of good ideas over at gs resources but that isn't one of them.  I wouldn't touch that one with a 10' pole.  You can change valve shims with a couple of screwdrivers, no need for the special tool.  Also don't check GS500 valves with the cam lobes set away from the valves, set with engine on timing mark and camshaft notches towards and then away from each other as shown in the manuals to get accurate measurements.


Is this correct? I watched Kerry's video on checking valve clearances and I remember clearly that he says to turn the engine so that the cam lobes point away at a 90 degree angle away from the shim when checking for clearance. I performed the clearance check using both methods; the method stated in the Haynes manual, given by GS Jack above as well as the one given by Kerry in his video) and predictably get significantly different readings for each one. When following the method in the Haynes manual the cam lobes do not point away from the shims. I'm a bit stumped and would simply like to know which method will give you the appropriate reading.

Title: Re: Orientation of cam lobes when doing valve clearance checks...
Post by: the mole on November 23, 2009, 03:02:51 AM
What he said ^.
Title: Re: Orientation of cam lobes when doing valve clearance checks...
Post by: tt_four on November 23, 2009, 07:29:48 AM
Yep, I watched that video and checked my valves the way Kerry said to check them, then noticed it was wrong and had to go back and do it all over again. Either way my valve adjustements were so far off that I couldn't even tell how tight they were because I didn't have gauges that thin, but still, do it like the manual says with the timing marks.
Title: Re: Orientation of cam lobes when doing valve clearance checks...
Post by: centuryghost on November 23, 2009, 09:21:39 AM
Timing marks!!!
Title: Re: Orientation of cam lobes when doing valve clearance checks...
Post by: El motociclista on November 23, 2009, 02:12:06 PM
Ok, thanks guys, that sounds pretty definitive then. But does the fact that I have the Bob Broussard ignition advancer mod make any difference in the way the cam lobes are aligned relative to the position to the timing marks??
Title: Re: Orientation of cam lobes when doing valve clearance checks...
Post by: El motociclista on November 25, 2009, 02:13:39 AM
b u m p...

anyone no if having an ignition advancer mod might change the orientation of the cam lobes in relation to the position of the timing marks on the rotor? The Hayne's Manual calls for aligning the timing marks a particular way when checking valve clearances. I just want to be absolutely sure I will be doing the job correctly to get the appropriate measurements. Thanks
Title: Re: Orientation of cam lobes when doing valve clearance checks...
Post by: joshr08 on November 25, 2009, 03:39:02 AM
ingition advancer will not change cam timing only changes ingnition curve.,
Title: Re: Orientation of cam lobes when doing valve clearance checks...
Post by: gsJack on November 25, 2009, 06:38:25 AM
Just make sure the camshaft notches are aligned horizontally (both inwards or both outwards) and the shafts will be where they should be for valve checking.  It will put the ignition mark off 5 degrees if you have a 5 degree advancer or whatever it is.  Just eyeball it, it will be close enough.
Title: Re: Orientation of cam lobes when doing valve clearance checks...
Post by: El motociclista on November 25, 2009, 01:00:39 PM
Great, thank you guys very much.   :cheers:
Title: Re: Orientation of cam lobes when doing valve clearance checks...
Post by: vorBH on April 13, 2010, 01:49:32 PM
Hey guys
So when doing the clearance for EACH of the 4 seperate valves....each time...the lobe should just be facing away? And then stick the feeler gauge in?

Is Kerry's right or wrong?
Title: Re: Orientation of cam lobes when doing valve clearance checks...
Post by: Paulcet on April 13, 2010, 05:59:20 PM
I think the general consensus is that Kerry's video is wrong, or at least not 100% correct.  If you do it the way Kerry says, there is no harm in it, it just gives extra clearance, which may give you less power by a small amount.
Title: Re: Orientation of cam lobes when doing valve clearance checks...
Post by: vorBH on April 13, 2010, 06:32:07 PM
Oh - I definitley dont want to lose any power!!
So what is the correct way to do it?? Does anyone have service manual for 07 500F?
Title: Re: Orientation of cam lobes when doing valve clearance checks...
Post by: Paulcet on April 13, 2010, 06:38:23 PM
Quote from: gsJack on November 25, 2009, 06:38:25 AM
Just make sure the camshaft notches are aligned horizontally (both inwards or both outwards) and the shafts will be where they should be for valve checking.  It will put the ignition mark off 5 degrees if you have a 5 degree advancer or whatever it is.  Just eyeball it, it will be close enough.

What he said  ^^^
Title: Re: Orientation of cam lobes when doing valve clearance checks...
Post by: vorBH on April 15, 2010, 07:22:18 AM
QuoteJust make sure the camshaft notches are aligned horizontally (both inwards or both outwards)

Does that mean...the lobe above each of the valves....wait horizontally??

Quoteshafts will be where they should be for valve checking.

I'm just not good with the terms, but can do it if someone can help with the words..thanks..
Title: Re: Orientation of cam lobes when doing valve clearance checks...
Post by: CliffHanger on April 15, 2010, 07:32:14 AM
Quote from: vorBH on April 15, 2010, 07:22:18 AM
QuoteJust make sure the camshaft notches are aligned horizontally (both inwards or both outwards)

Does that mean...the lobe above each of the valves....wait horizontally??

Quoteshafts will be where they should be for valve checking.

I'm just not good with the terms, but can do it if someone can help with the words..thanks..

The camshafts have a notch in the end, this in no way refers to the the cam lobe.
When the notches (of the Intake and Exhaust camshafts) are aligned to each other, the measurements should be made.

Also, with the notches inwards, I believe three valves are in position?
The notches need to be aligned pointing outwards for the fourth.
Title: Re: Orientation of cam lobes when doing valve clearance checks...
Post by: vorBH on April 15, 2010, 07:00:30 PM
Hmmm so which one is the notch? Can please kindly indicate in the photo? and re-post?...http://gs500e.free.fr/entretien/carb_valves_chain/download/topengine.jpg

umm can someone KINDLY photocopy that part of the Hanyes manual (valave clearance check and how to do...and any other related parts of manual)  :cheers: :cheers:...so I could see it clearly...I don't know how I would thank somebody genuinely for helping me like that, help a fellow GS keep well  :)...I have an 07 500F though...should be same no?
Title: Re: Orientation of cam lobes when doing valve clearance checks...
Post by: Paulcet on April 15, 2010, 08:37:04 PM
Quote from: vorBH on April 15, 2010, 07:00:30 PM
Hmmm so which one is the notch? Can please kindly indicate in the photo? and re-post?...http://gs500e.free.fr/entretien/carb_valves_chain/download/topengine.jpg

umm can someone KINDLY photocopy that part of the Hanyes manual (valave clearance check and how to do...and any other related parts of manual)

Check the link in this post: http://gstwins.com/gsboard/index.php?topic=49127.msg562620#msg562620
Title: Re: Orientation of cam lobes when doing valve clearance checks...
Post by: vorBH on April 16, 2010, 09:21:13 AM
THANK YOU!! :D :thumb: