Just took delivery of a 2005 'Blade from an eBay purchase a few days ago. It replaces a 2001 Erion 929 that I sold a couple of years ago and have been missing. The bike has about 8900 miles and is all stock. The bike has the "knock at idle" that's described in several of the threads on this forum over the years. The original owner, who seems to be an honest sort, says it's sounded the same since he took delivery from the dealer, so he guesses it's normal. The local Honda service manager says he "thinks" maybe it sounds abnormal, but he's not sure, and he has no idea concerning the origin of the sound.

Like the other posts, the sound occurs only at idle, it makes no difference whether the clutch is in or out, no difference whether the transmission is in gear or in neutral, and the sound disappears instantly when any load is put on the engine (e.g., holding the brake and beginning clutch engagement or simply beginning to pull away from a stop). The sound isn't entirely constant, it'll "miss a few beats" occasionally, and seems to come and go, but is mostly present. I changed the oil and filter, but that made no difference at all in the sound.

The previous posts on this subject are fairly inconclusive, with most folks rejecting rod knock or cam chain rattle because of the instant disappearance under load. Any new thoughts or research out there? I welcome your comments. (By the way, the 929 didn't make the sound at idle.) Thanks in advance for any help you can offer.

hi. I can't offer any real advice other than to say i've just bought a 2006 model with 3500 miles on it and full main dealer service history, and it's got exactly the same issue! I guess it's reassuring in a way?

I've heard this before with this bike, funny thing is the bikes that have this noise always seem to run fine. I would suggest you take your bike to a performance shop with a dyno rather than the stealer. (dealer)

If the idle is too low bike engines start making lots of strange noises.
If you increase the idle by 100rpm does it help at all?

Gentlemen,

Thanks very much for your replies. I figured this thread was buried and forgotten by now, so I'm pleased to see some responses. Your comments support the seller's claim that it's made the sound since coming off the showroom floor. As noted, the bike runs perfectly notwithstanding the mysterious sound, so I guess I won't lose a lot of sleep thinking about it. Regarding the idle speed, it was just a touch high when I got the bike. When I lowered it a few rpm, the knock seemed to fade somewhat to the point of almost disappearing. Go figure. Maybe something resonates at some given low rpm and no load. (Not a very good theory, but it's the best I have at this time of the morning.)

There is an independent shop run by a fellow with years of Honda experience not far away. I imagine his opinions are free, so perhaps I'll take it by sometime and see what he thinks. If I do, I'll post his thoughts on this thread for the benefit of others.