Engine knock on tickover when warm

[kenb]

I recently bought a 1993 model with 30,000 on the clock. It always starts first time and runs smoothly flying effortlessly up into the 90s but after warming up, with the bike on tickover between 1100 and 1300 rpm, there is a regular metallic knock/loud-tick that appears to be coming from the front left bottom engine cover or the front of the rocker box cover; hard to tell. It varies in loudness and sometimes not there at all. Once running it seems to disappear. I've had the rocker box covers off and everythng looks fine: timing chain ok; valve clearance ok; cam shaft sprockets ok; timing chain tight. I've checked the timing chain tensioner and it looks fine and springs out freely when released.
Any suggestion would be much appreciated before I start what could be unnecessary dismantling.

Thanks

KenB

[starwalt]

I recently bought a 1993 model with 30,000 ...there is a regular metallic knock/loud-tick that appears to be coming from the front left bottom engine cover or the front of the rocker box cover; hard to tell. It varies in loudness and sometimes not there at all. ...

Sounds like the camshaft endplay noise common to this engine. Try a search here for this term for other posts on this. There is no real cure for this as it seems to be a temperature related issue with component expansion in the valve train. At least no one has reported a shim kit from Suzuki to address this.  

[DerekNC]

Mine started doing the same thing after I did the valve adjustment. It went away on it's own after 4 or 5 rides so it seems to be okay now. If it just started doing it give it a little while to see if it quits. Maybe just the camshaft endplay like Starwalt said.

Derek

[Kerry]

Actually, there IS a set of shims that you can choose from.  For the '93, see items 3 and 10 on this page (click "Continue").

For more discussion, including the experience of one person (erezshlez from Israel) for whom the shims actually worked, see the Engine noise?  Where from? thread.

But before buying any shims, you may want to pull the valve cover again and see if you can move either of the camshafts from side to side.

[starwalt]

Aha! It is good to know some offering is available. Kerry slugs through so many posts I am beginning to wonder if he is GSTwin and not some PC in a rack somewhere!  :lol:

Dare I say shades of "Johnny Mnemonic"  

[knowlsey]

Thanks for this, i have just finished rebuilding a bike, which the engine i knew nothing about till i fired it up. And it done exactly what been explained here, bugged the hell out of me, as when cold, no noise, when warm, a noise, so stripped cover off ,as you do, nothing slack nothing loose, but noticed cam end play, wondered if it could be these, and hey presto, do a search on here and find that it is the problem, seems to be the earlier models around 93 as mine is 94. Was going to replace camchain adjuster but that was fine, as you can understand it bugs you when you can not see a problem, but you can certainly here it.And when its a metal clanking sound its a bit scary.

I can understand it not been to much of a worry, but has anyone actually replaced the end cam shim washers, and has it cured the problem

[That guy]

Dare I say shades of "Johnny Mnemonic"  

ohh im gonna rent that movie tonight. Good call