So, a while back, I did a valve clearance adjustment. After changing shims, I went to rotate the engine again to check the other exhaust valve and felt some resistance, so I stopped, and realized I had forgot to remove the paper work towel I had shoved between the camshafts to prevent anything falling in there and it had worked it's way up and over the camchaft sprocket. I ended up taking out the cam chain tensioner to loosen the chain enough to work the rag out from between the chain and the sprocket. I checked the last shim, and put everything back together. It was during the winter so I didn't ride the bike for a few months after, but I did start it up and it seemed to run fine.
Fast forward a few months and I start riding the bike again and notice some preignition engine knock at idle. I figured it was due to an ignition advancer (rotor) that I had installed at about the same time over the winter. I took the ignition advancer out and still notice the engine knock. When I had changed the valve shims, I took the advice of some of the members on this board and went with larger clearances at the top end or even just out of spec, so I thought maybe that might be the cause.
Today, I pulled the valve cover off to check clearances again. I'm reading the service manual to find the correct location to rotate the engine to. I line up the RT marks on the ignition rotor and look at the notches on the ends of the camshaft to make sure they're aligned correctly. I notice the exhaust notch looks a little off -- it's not completely level. I read the part in the service manual about the timing marks on the cam chain and the exhaust cam is one chain notch off (the exhaust camshaft is rotated towards the intake camshaft one more notch than it should be. f%$k! It's a wonder I didn't blow up the engine.
I loosened the cam chain again to see if I could just slip the exhaust camshaft a notch on the chain, but when I did that I realized the exhaust camshaft was still pushing on the other exhaust valve and couldn't be moved. Even worse, it ended up slipping *another* link on the chain, so now it's two chain links off!
I'm not sure exactly what the best thing to do is now. The only thing I can think of is to remove the camshafts entirely and follow the installation instructions to realign the timing.
Any help is appreciated.
The easiest thing is going to be to remove the cam chain tensioner, then the camshafts and set it according to the manual.
Doing what you are trying, you are fighting the cam chain tensioner. The Hanes and Clymer manuals have good instructions on how to do this.
So a question about cam timing. I'm looking at the manual and it says to align the 1 arrow on the exhaust cam so that it's parallel to the top of the engine block. I'm expecting the notch on the end of the cam shaft to also be parallel to the top of the engine block. But it ends up looking a bit like this, with the notch angled upwards. Is that right?
(http://beergarage.com/imgs/GS/Timing/92.jpg)
No that doesn't look right but it's been 10 years since I pulled my head to replae a broken valve and reassembled and timed the cams. I recall it wasn't exactly on the line but very close, much closer than that pic. It should look like this drawing shows, I made this putting 2 drawings from the shop manual together to show engine timing:
(http://img.photobucket.com/albums/v443/jcp8832/gs500signalgenerators_zps6gldzd0e.jpg)
By the way, what's all the talk about removing the cams to correct a one tooth off issue? Best as I can recall you can put the crank on the R-T mark with cam notches inward and remove the CCT and then just unbolt the cam gear and slide it off the shoulder and have enough loose chain to make a tooth or two correction. Correct me if my memory is fading faster than I thought. :icon_lol:
I don't reccommend removing the camshaft bearing caps any more often than necessary, too many have screwed them up doing this. Stripped bolts, broken caps, etc.
You may be right, its been awhile since I was that far into my engine. If the OP can correct the timing without removing the cam journals, that would be a better solution. Those journal bolts might as well be made of clay.
Not to hijack this thread but a quick question. When checking the valvle clearances why do you need to align the RT marks etc? As long as the cam is not pressing down on the valves wouldnt that be enough to insert the feeler gauges to check the clearance?
From personal experience, you will get slightly different measurements depending on where the engine is in its rotation even if the cam lobe is off the shim. To be able to compare apples to apples, always measure per the manual.