Any links to adjustable cam spockets? Long first post.

[vroomvroomvroom]

Hello all,
I have just rebuilt the top end of my GS500 ('89).  Shaved the cylinder head 0.010".  Valves and seats reground.  New piston rings and honed cylinders.  New gaskets and carbs synched.  

The engine is running pretty sweet.  I am concerned about the change to cam timing I made by shaving the cylinder head.  I am wondering if anyone has a link to adjustable cam sprockets for the 500.  I tried A.P.E. to no avail.  I am going to do the checking of the timing soon.  That will be a bit of a chore since the valve cover holds down the cam chain in the center, I will have to devise a pulley to push down on the chain for the degree checking.

I read posts hear about the engine knocking some are hearing.  I have heard the same bothersome noise.  I don't hear it when my engine is cold.  Then as the engine is warming up it begins to knock from apparently the valve train, only at idle.  If I warm the engine extensively or ride it longer the engine noise will not occur.  I heard the noise before I did the upper engine work, I just am noticing it a lot more know.  Before I would just hear it occasionally when I was on the front brake and wonder WTF.  Now I can hear it a idle intermittantly.  I am going to look into the cam end play possiblity I read on other posts here.  I am almost tempted to pull the whole engine apart to see what the bottom of the engine looks like.  I know it is not valve clearance or cam chain tension.  Sure doesn't sound like piston slap or lower end bearing noise (both of those would 99% of the time be more noisy at cold start or when hot, which my noise is neither).  

The noise is a loud audible (most likely cam speed) knock, like a hammer tapping on steel plate.  I hear it more on the brakes when the engine returns to idle.  I have theorized that it could be the cam lobe slapping the valve shim, or the shim slapping in the bucket.  This brings me back to the cam timing possiblilty.  I have seen engines that when the cam overlap is way off, causing too much lope at idle, the engine will fight it's forward motion and cause clashing noises (same type of thing can happen with carbs that are out of synch, each cylinder wants to go a different speed).  

I notice this knock more now after increasing the performance with the upper engine overhaul.  I used to only hear it occasionally when I was on the brakes when the engine was semi-warm (as I stated above).  I always wondered if the knock was the bike next to me, or whatever.  I was always mystified by the noise, because it only happened at these conditions.  I shrugged it off as being something else.  Now that the noise is showing itself at idle, I have done more investigating into it.  Which lead me to the inquiry here on this site.

Another mod I have thrown around:  Has anyone tried removing the balance shaft and having someone balance the crank to compensate?... ala GSXR1000 racing mod?... How much more will it vibrate?  Mine already is pretty vibey.  Does yours vibrate the gas tank enough to consistantly groan on acceleration, especially thru the mid range part throttle?  I don't find the current vibration all that bothersome as long as I keep my legs away from the tank (yes all the rubber bumpers are there, and then some!).

vroomvroomvroom

[Gisser]

:dunno: Does shaving the head warrant degreeing the cams?  

Figuring cam sprockets go 2 1/2'' diameter...

Pi x r sq'd /360

...leaves .010'' at less than 1 degree.  

[Blueknyt]

cam timing shouldnt be effected, unless you took off gobs of matirial. the cam chain tensioner would take up the slack.  an aftermarket cam chain adjuster might be the ticket there, im still refining my Modded chain tensioner.

[Blueknyt]

I have seen engines that when the cam overlap is way off, causing too much lope at idle, the engine will fight it's forward motion and cause clashing noises

again, the timing chain if properly tight would keep that from happening, the tensioners on these bikes seem to be a moderately weak point. might even be what helps the top ends go so soon before the bottomends.

[dgyver]

A couple of things that I have come a across. My knocking was from the pistons slapping in the cylinder. Since you had yours honed, it is possible that there was too much material removed (along with the increase in compression from the head mill) and causing the same thing. Since it goes away as the bike heats up, the piston & sleeve are expanding and the clearance decreases. It would be a good idea to double check the piston-cylinder dimensions.

Cams lobes hitting the shims will make a ticking sounds, not a knock.

Contact Megacycle about degreed cam spockets.

Some have removed the balance shaft. Try the search button.


BTW...will a SV cam chain tensioner fit the GS?

[Reknelb]

.01" off the head will retard your cam timing.
Take the cam sprockets off and slot them yourself.