I have inherited a 2004 GS 500 (6600 miles) that ws dropped at 45 MPH on the left side and was stored for about 9 months.  I replaced the left crankcase cover ... does not appear to have damaged the stator.  Starts up OK, but after warmup, any throttle action killls the engine. I figure the carbs are probably clogged, so I have opted to perform the complete scheduled mantenance.  Upon checking the cam follower clearances, the measurement changes each time I rotate the crank. It goes both ways.. the first check the clearance was spec, then the next time I checked it was out of spec.  Any suggestions?

Also I noticed oily residue on the left side of the engine near the head/block mating surface.  Loose head/Blown gasket?  I have the Haynes manual but when it talks about tightening the head bolts, it mentions the cap head nuts to be 10 MM.  Mine are 14 MM.  So I am suspect about the torque setting.  Anybody have better source of information for the 2004 model?

are you rotating the crank the same direction each time ?

the head tightening said 14 mm in my haynes... if that helps. i'd clean up the motor at the car wash, wipe it down, then go for a ride and see if the oil residue returns.

the carb issue- who knows. pull em apart and see how nasty it is .

Quote from: DesertTwin on May 13, 2008, 03:35:24 PM
Upon checking the cam follower clearances, the measurement changes each time I rotate the crank. It goes both ways.. the first check the clearance was spec, then the next time I checked it was out of spec.  Any suggestions?

Are you taking the measurement with the camshaft notches facing the same way each time? (figure 5.5b in Haynes)

The notches should face inwards for #1 cylinder intake and #2 intake & exhaust, and outwards for #1 exhaust

note: #1 cylinder is on left hand side when sitting on bike.

Quote from: DesertTwin on May 13, 2008, 03:35:24 PMAlso I noticed oily residue on the left side of the engine near the head/block mating surface.  Loose head/Blown gasket?

Does your bike have the stock air box, or after market filter(ie. lunch box, pod).

Always rotating engine in same direction when taking measurements. 

The camshaft ends on this motor do not have notches.  I just rotate the crank untill the camshaft lobe is 180 deg  away from shim for each of the valves.  Is the follower hollow or can oil build up under the shim?

Air box question: Looks to be stock air box with paper/screen cartridge.

Quote from: DesertTwin on May 13, 2008, 07:38:28 PMAir box question: Looks to be stock air box with paper/screen cartridge.

The hose from the top of the valve cover to the air box can cause that if it becomes disconnected. The reason I asked about after market filters is that hose is usually left just hanging on the side of the motor with a small filter or something on it.

Quote from: DesertTwin on May 13, 2008, 07:38:28 PM
The camshaft ends on this motor do not have notches.

Are you sure? This thread reports a similar issue as yours and shows a photo of where the notches can be found:
http://gstwins.com/gsboard/index.php?topic=17579.msg157332#msg157332

QuoteI just rotate the crank untill the camshaft lobe is 180 deg  away from shim for each of the valves.

The measurement position is not 180 deg., it is slightly offset. It seems like it shouldn't matter, but it's easiest to get to the bottom of this if you eliminate all deviations from the Suzuki test procedures:

QuoteIs the follower hollow or can oil build up under the shim?

Oil can get stuck behind the shim when you first install it. Rotating the engine a few times displaces the oil and seats the shim.

My bad.  I have notches.  I am working from the left side of the engine, so I never noticed them on the right side of the camshaft.     I'll perform the measurements using the stated procedures and report back.

Measurements repeated twice.  #1 intake is < .038 mm (smallest feeler gauge I have) and #2 exhaust is between .102 mm (Go) and .127 mm (NoGo). Everything else in spec.  Is a little loose better than close to the tight side (especially for the exhaust)?

beRto : Thanks for pulling my head out of a dark place.

As for head torque, what should it be?  My Haynes book (#3238) indicates that the 10 mm domed nuts should be torqued to 35 to 40 Nm and the 6 mm plain nut to 7 to 11 Nm.  The domed nuts on my head are 14 mm and the plan nut is 10 mm.  Do I have an older book that needs to be updated?.  I tried to loosen the head nuts but I way exceeded the listed torque. 

ohgood:  Your manual indicate 14 mm domed cap nuts.  Which manual iare you referring to and what is the listed head torque?

Quote from: DesertTwin on May 13, 2008, 09:34:51 PM
Measurements repeated twice.  #1 intake is < .038 mm (smallest feeler gauge I have) and #2 exhaust is between .102 mm (Go) and .127 mm (NoGo). Everything else in spec.  Is a little loose better than close to the tight side (especially for the exhaust)?

If it were me, I'd buy the correct replacement shims and get both valves within spec. Others (including the venerable gsJack) are less picky; gsJack states that he has often gone a little loose on exhaust valves
http://gstwins.com/gsboard/index.php?topic=39201.msg440244#msg440244

This thread also gives some relevant advice:
http://gstwins.com/gsboard/index.php?topic=39209.msg440255#msg440255

QuotebeRto : Thanks for pulling my head out of a dark place.

Glad I could help! 

Quote
As for head torque, what should it be?  My Haynes book (#3238) indicates that the 10 mm domed nuts should be torqued to 35 to 40 Nm and the 6 mm plain nut to 7 to 11 Nm.  The domed nuts on my head are 14 mm and the plan nut is 10 mm.  Do I have an older book that needs to be updated

Your Haynes manual should indicate which model years it covers.

My Suzuki shop manual (2004 supplement) says:

• Cylinder head cover bolt - 14 Nm
• Cylinder head nut - 38 Nm
• Cylinder head bolt - 10 Nm
• Cylinder stud bolt - 15 Nm

Sorry, I didn't find a diagram indicating exactly which bolt is which. That being said, the numbers seem to agree with the Haynes specs you quoted. Hopefully someone else can expand on this.

Quote from: DesertTwin on May 13, 2008, 07:38:28 PM
Always rotating engine in same direction when taking measurements. 

The camshaft ends on this motor do not have notches.  I just rotate the crank untill the camshaft lobe is 180 deg  away from shim for each of the valves.  Is the follower hollow or can oil build up under the shim?

Air box question: Looks to be stock air box with paper/screen cartridge.

I tried checking valves on my 1st GS by setting cam lobes at 180 from the shims like I did on my previous Hondas and also got inconsistant results like you did.  Set them on timing marks like the book says and results will repeat every time.  Also you can do 3 valves at one setting and rotate cams only once for the 4th.

Quote from: DesertTwin on May 13, 2008, 09:34:51 PM
Measurements repeated twice.  #1 intake is < .038 mm (smallest feeler gauge I have) and #2 exhaust is between .102 mm (Go) and .127 mm (NoGo). Everything else in spec.  Is a little loose better than close to the tight side (especially for the exhaust)?

The .038 mm = .0015" and is to spec, my 97 GS went 88k miles w/o changing either intake shim.  Exhaust valves receed into the seats and one on the 97 was down to min shim.

The .102-.127 mm = .004-.005" and that's exactly where I set mine last time I changed shims on the 02 GS.  Exhaust valves seem to be lasting longer with the greater gaps giving more cooling seat time; I'll know better after I get around to my overdue check, the 02 has 59k miles on it now. 

http://img.photobucket.com/albums/v443/jcp8832/valveclearances.jpg

I'd stick to specs on the valves if I was redlining it on a track but I rarely go over 9k rpm and have only hit redline a few time in 130k miles of riding, little chance of throwing a shim that way.

Quote from: DesertTwin on May 13, 2008, 09:34:51 PM
My Haynes book (#3238) indicates that the 10 mm domed nuts should be torqued to 35 to 40 Nm and the 6 mm plain nut to 7 to 11 Nm.  The domed nuts on my head are 14 mm and the plan nut is 10 mm.

The 10mm and 6mm are in reference to the diameter of the threads.  Manufacturer's use this as a logical means of reference.  It avoids the confusion of ordering 12mm nuts for 10mm threads.