Setting the cam chain - same for all years?

[Bluesmudge]

I just did a valve check by removing the cams because I couldn't get the motion pro tool to work.

I just wanted to double check that all the cam chain settings are the same across all years of GS500's. I'm using this link:
http://beergarage.com/GSTiming.aspx
And the Hanes manual as a guide but both are for older GS 500 models. Mine is an 06. Is the info for setting up the cam chain still the same?

When I'm turning the engine using the big bolt under the right hand side cover should I be feeling a distinct kind of jerk as each piston reaches TDC? - because I am and it feels a little weird.

Thanks!

[adidasguy]

Did you remove the spark plugs? You should do that when turning by hand.

[Bluesmudge]

Yes, spark plugs are removed. I'm worried that because I turned the engine over while the cam chain tensioner was out that I could have jumped teeth at the crank...

[Bluesmudge]

It almost seems like the valves are 180 degrees of where they should be compared to the piston location. I must have been jumping links at the crank when I was turning it over w/o the cam chain tensioner. To get the marks on the cam facing eachother i have to have the pickup at LT. Shouldn't it be RT?

Am I f%$ked, or can I drain the oil and take off the rit side engine cover to get to where the cam chain goes to the crank? Are there similar markers to set the cam chain timing at the crank as there are on the cam chain sprockets? Or can I take the cams off and move the timing chain around to the correct position and then put the cams back on?

[adidasguy]

Cam chain goes over 3 sprockets. Two at the top and one down deep.
adjusting the top is all you need to do.
Think about it - a chain is a continuous loop. Adjusting 2 of the 3 points is all you need to do. Like leveling a tripod: you only need to adjust 2 of the 3 legs to be level. Same with a timing chain: adjust 2 of the 3 sprockets. In this case: the top two is enough. Where ever the bottom is - you can adjust the top two to be correct in relation to it.
Dave & Scotty are really good at this. Give them a jingle.

[Bluesmudge]

Okay. I guess the problem was that I adjusted the intake cams to the exhaust cams but the exhaust was already not in sync with the crank. So I just need to set the crank at Right Top Dead Center, then set the exhaust to that and then the intakes to the exhaust. that will be much easier than the way I was planning on doing it!

[gsJack]

The mark for locating the crankshaft is on the rotor so you just remove the small 3 bolt cover over the signal unit and line up the R-T mark on the rotor with the coil centerline and your crank is positioned for correct timing of the camshafts with the marks on them.  No need to see the sprocket on the crankshaft.

[Bluesmudge]

Is it literally the text "RT" I line up with the coil or is there some other identifiable mark so I know the crank is exactly where it needs to be? I can also just stick something in the spark plug hole to make sure the right piston is at the top of its stroke.

[gsJack]

I don't have a pic of the 04 and later single coil signal setup but there must be a line next to the R-T mark for TDC point.  Here's pics of my 02 two coil setup on the marks for valve adjustment:




As far as confirming which piston is on top I found I could see the piston by shinning a flashlight in the spark plug hole if the piston was near the top and then adjust to the mark.  Actually I'm not sure if you have a RT or a LT mark on your rotor but you must have one or both, in my first post I was just pointing out that the crank is positioned with the ignition timing marks when timing the camshafts.  I found a shop manual that covers 00-09 GSs and for the 03 and later they show the timing marks on the camshaft sprockets to be same as the older models with the same link count between camshafts.  Unfortunately they used an old pic of the signal coil and marks.

[Bluesmudge]

gsJack, thanks for clarifying with that picture! My picture has both an RT and an LT.

Just to confirm, I want to set the camshaft sprockets as described by the shop manual during Right(throttle side) Top Dead Center (RT Mark) not LT as shown in your picture?

[Bluesmudge]

Okay, I got the timing correct 

Unfortunately, now both exhaust valves a that I just got the correct shims for are now completely out of spec. They both have a clearance around .5mm (not .05). I'm not sure what's causing this but I know it's a result of something I did since I took of the cams because my original clearances were extremely tight and now even those shims would give me a very very loose clearance.

I double checked that the cam is seated correctly. Is something causing the valves to not return to their normal position?

Should I just swap for some really thick shims and call it good?

Update: intake clearances are now both .02mm even though they were both in spec prior to removing the cams. Something is causing the intakes to be tight and the exhausts to be loose. I have no idea what that could be. None of the valves look bent or broken.

Would there be any problem starting from scratch with my valve check and just getting shims based on my new measurements? According to the clearances I have now I would need a 300 and a 295 for my exhaust valves even though a 275 and a 272 were too tight before removing the cams.

[gsJack]

Like BeerGarage said in his write up: "I'm looking for top dead center (TDC) on the right piston. When the RT (Right Top) mark is on the rear pickup, that is RTDC, Right piston, Top Dead Center."  My timing mark pics show the RT at the rear pickup when the LT is at the right upper pickup.  The crank is the correct position for timing the camshafts and with the camshaft notches pointing inwards as they should be after timing them correctly the clearances can be measured on the closed right intake and exhaust and the closed left intake valves.  The right intake and exhaust valves both being closed with the piston at top dead center confirm it is at the top of the power stroke.

Your slightly tighter intake clearances could be due to measuring them without the cams being right on the timing marks but I'd be concerned about the much larger exhaust clearances.  Assuming the cams are seated and tightened down properly the only reasons that I can think of would be sticking buckets or bent valves unless the new shims you put in were way too much smaller than the old ones, you didn't mention the sizes of them.  With cam lobes turned away from the shims you can check to see if you can turn the buckets with your finger tip indicating they aren't sticking.  A simple finger over the plug holes and crank the engine should blow you finger away with a loud pop if you have good compression indicating no bent valves.  No pop = bent valve.  Make sure cam timing is ok by turning over engine a few turns with the wrench before cranking it with the starter for compression check.

Like I said before, I'm not familiar with the timing markings on the 04 and newer single pick-up coil setup you have.

[Bluesmudge]

The exhaust buckets were very difficult to put back into the head. One of them is now difficult to turn and the other one is basically impossible to turn by hand. You think that could be the problem?

[gsJack]

Possibly, but I'd do the finger over the hole compression test first to see if valves are closing, no guage required.

[Bluesmudge]

Just did the test. No compression coming from the left and almost none coming from the right. I probably bent the valves when I had the timing all wrong. Live and learn.

I'm getting the whole top end for a good price from steezin_and_wheezin. I figure I'll just swap the entire thing out. Anyone know if I can replace the head w/o pulling the engine from the frame? It looks like it would be possible.

[gsJack]

I pulled my 02 GS head about 70k miles ago to replace a broken exhaust valve caused by a sticking bucket.  Pulled head with engine in frame, very tight but it goes up and out after moving wires from right inside frame member.  I just left the carbs hanging on the throttle cables over the left side while doing it.

I finally found a pic of the 04 and later single coil signal generator timing marks, seems they were first used on a 98 GS in France:

[Bluesmudge]

Are there any parts I need to order other than a new head gasket and a cylinder head o-rings (items 10 and 11 in the diagram)?

[gsJack]

Many say always replace the cylinder base gasket too when removing/replacing the head or it might leak later from being disturbed.  I put a new head gasket on an old CM400A to fix an oil leak years ago and didn't replaced the cyl base gasket and it always leaked a little for the 60k miles I used the bike after that.  When I repaired my current 02 GS I replaced the cyl base gasket and it's only seeped a bit in the 70k miles since then.  The head gasket and o-rings are about $50 and the cylinder base gasket is less than $10 so if I had to do it again I'd replace the base gasket again.

[Bluesmudge]

That makes sense. Thanks for all the help! I'll let you know how it goes. Will take awhile to get all the parts in.