Join Date: Apr 2011
Location: Brookfield, MA
Thanked 438 Times in 281 Posts
Oh sorry, I assumed this was a used bike.
I'm not a mechanic, just a DIY'er who has done 95% of the maintenance on my bike since buying it new in 2011.
Generally, I believe that heat is the biggest culprit in developing valve problems. Continually running the bike hot due to insufficient or incorrect oil or not changing the oil according to the maintenance schedule could lead to valve problems. If you're the original owner and had the bike checked at 600 miles, change the oil regularly and don't flog it at redline all the time when you ride I highly doubt that valve adjustment is your problem. On first-year bikes like mine some engines left the factory with the valves set too tight, which led to the 600-mile check being established by Honda. Very few of them, but Honda played it safe and recommended the 600-mile check. Many bikes, like yours, mine and many other owner's, have needed no adjustments at all at 600 miles, but Honda kept the recommendation in their owner's manuals.
As jkv357 said earlier in this thread, valve noise is more of a "ticking" sound than a "rattle" and many owners have complained about "rattles" in this forum over the years. There are a lot of things on the bike that can cause "rattles", but in the rare cases where the cause has actually been found it's rarely been from valves. It's usually from the chain or some other moving part.
Also as jkv357 said, he'd check the valves just to be sure and there's nothing wrong with the advice, but be aware that many people here have never been able to exactly pinpoint the cause of "rattles" on this bike and there's also the distinct possibility that what you're hearing is "normal" for the CBR. The CBR single-cylinder engine is pretty bullet-proof and extremely reliable. If you're at 12,000 miles already I'd just live with the noise until the scheduled 16,000 mile check and consider that while the "rattle" may be a little annoying and noticeable to you, it could also be perfectly normal for this bike given all the complaints of rattling this bike gets. One thing I see way too often on this forum is owners giving too much importance to noises the bike makes in normal operation that aren't really a problem at all. As long as you're not losing power and the bike is behaving normally despite a little "rattle", I'd live with it for another couple of thousand miles and see if anything is found in the 16,000 maintenance, rather than tearing the engine apart chasing a "rattle" on your own so close to a scheduled valve check.