in my experience the clearance shrinks, but I never had a brand new bike, either
I've heard that a new bike's clearances sometimes open up at first as parts  wear, but when I checked mine on my 07 with 4500 on the clock. they were tight

thanks all .I hope we can get a fair # of posts and see what the concusses might be . sometimes its better not to mess with things .

The adjuster is pointed like a dull pencil. As time passes it gets mashed and mushrooms out a bit. That increases clearance. The tip slows down in changing shape. The area increases and the metal work hardens. Miles between adjustments increases. Cam wear or rocker wear increases clearance.
If the valve seat wasnt pressed fully into place at the factory then clearance could drop below minimum recommendations from the valve spring slapping it shut pounding the seat into its land. Valve wear,where it hits the seat decreases clearance, but it is miniscule.
At 5,and 10 thousand miles they were sloppy. At 15, not so bad, at 20, still in spec.

If there's a valve adjustment sticky,
Just saying.

If you have the tank off you might as well take the few minutes it requires to check the valve clearance.  Chances are they are fine but you don't know if you don't check.

jcstokes wrote on 05/14/15 at 01:31:05:


You can buy loose/separate feeler gauge stock from Graingers, McMaster-Carr, etc.  You just bend it the way it works best.

It makes the job as easy as it can be.

Off the top of my head I think Suzuki recommends checking every 5000 miles. If you're really bored, go ahead and use their spec. Otherwise, a smooth engine is a good engine.