What bike, mods, exhaust etc
My Firebolt makes an unsettling metallic rattling sound when I get on the throttle. This only happens when I've been riding for a while (20-30 minutes in hot weather) and the engine is hot. What could be causing this?
What bike, mods, exhaust etc
Hard to tell from your comments. Is it spark ping (pre-detonation)? Have you ever heard that noise before? Try higher octane fuel see if it goes away.
It's a 2004 xb12r with a race ecm, drummer exhaust, and it's been lowered with a lightning rear end and lowered on the stock forks (previous owners). It has had this noise for a while. It sort of sounds like metal screws being rattled in a metal can. I can accelerate slower and ride at any rev it doesn't make the noise. It's only under moderate to hard acceleration that the bike makes the noise. I just looked up some videos of spark ping but it doesn't sound like this https://www.youtube.com/watch?v=VjlL3C4EsNM it's more metalic sounding.
Try higher octane fuel see if it goes away.
You may also have carbon build up for which you could try a detergent fuel additive. If that fails, you might try a set of cooler plugs.
If the knocking persists, I'd check that the CPS is operating & set correctly.
I'm running 91 octane, but I can't find any higher. Where do people get 93?
It might just be normal. All my Buells make a sound similar to hitting the motor w a ball peen hammer.
I'm getting the same noise too! No loss in performance but "pings" under hard acceleration. 2004XB12 with NGK Irridium 9 plugs (which I believe are cooler than the 8 plugs that the XB calls for). Always run 93 in it. I used to hear it with my Hawk and still hear it with the Torque Hammer so I don't think it's something loose in the exhaust. It would be nice to cure this...
If you want to rule out pre-ignition as the cause, you could buy a bottle of Octane booster at an automotive store and run with that for a while. You should easily be able to get above 100 octane.Originally Posted by canadahippie
This isnt exactly true. Most of those octane boosters are garbage and increase your detenation point hardly anything.You should easily be able to get above 100 octane.
If you have ecmspy and a cablr, increase the AFV by 10 to 15 percent once the noise starts and go for a ride. If its detenation should go away.