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cbr 600 f4i low speed knocking

Started by dearmash, September 09, 2009, 12:56:30 PM

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dearmash

I've been noticing this off & on for a couple of weeks now.  Just when starting from a standstill and only up to about 4-5k rpm in 1st gear, there's a couple of noticeable knocks coming from below.

Any comments, suggestions, ideas?

MotoPutz

Without hearing it I couldn't begin to guess...

mikey

possible ignition ping?  are you getting cheap fuel? maybe fill it up with chevron or shell 91oct
ducati brothers

916 (2wcp 955 big bore kit)

mikey

ducati brothers

916 (2wcp 955 big bore kit)

JetFueler

Hopefully not a rod bearing.  Make sure oil level is up to par.  The bad fuel could be it too.  Try using atleast 91 octane or some racing fuel.  100 octane is great stuff.  VP or Sunoco.
And God will cause me to ride upon the high places of the earth.  (Isaiah 58:14)

dearmash

The bike has new (<1k miles) oil, nothing but 91 shell or chevron.  Spark plugs are something I think I can check and probably are original, if that's a culprit.

SPL

Quote from: dearmash on September 10, 2009, 01:35:04 PM
The bike has new (<1k miles) oil, nothing but 91 shell or chevron.  Spark plugs are something I think I can check and probably are original, if that's a culprit.

Got your PM, will be calling you shortly. Its not rod bearing my friend. 
Building Dreams One Bike At A Time!  775-825-4457

dearmash

Quote from: Superbike Performance Lab on September 11, 2009, 11:04:33 AM
Quote from: dearmash on September 10, 2009, 01:35:04 PM
The bike has new (<1k miles) oil, nothing but 91 shell or chevron.  Spark plugs are something I think I can check and probably are original, if that's a culprit.

Got your PM, will be calling you shortly. Its not rod bearing my friend. 

Glad to hear it, sounded expensive  :o  lookin' forward to hearin' from ya.  Thanks in advance

dearmash

Just to update myself & maybe others.

There's a chance that this is a broken tooth rattling around in my transmission.  Now I just need to figure out how to verify & then how to fix it.

MotoPutz


TWF

Quote from: dearmash on September 17, 2009, 10:12:52 AM
Just to update myself & maybe others.

There's a chance that this is a broken tooth rattling around in my transmission.  Now I just need to figure out how to verify & then how to fix it.
don't think so

Yard Sale

Yeah, it might rattle around for a nanosecond until it worked its way between gear teeth and locked up your transmission.




Do you have an ignition advancer of some kind on the bike?

dearmash

Quote from: Yard Sale on September 17, 2009, 04:34:14 PM
Yeah, it might rattle around for a nanosecond until it worked its way between gear teeth and locked up your transmission.

[img]

Do you have an ignition advancer of some kind on the bike?

My knowledge of an ignition advancer is restricted to the following google searches:
http://www.google.com/search?q=ignition+advancer
http://www.google.com/search?q=ignition+advancer+cbr+600+f4i

I haven't put anything on to the bike myself, but the previous owner did put on a power commander, though there isn't anything I've seen on the bike with "Ignition module".
As far as a mechanical ignition advancer, I'd have to call up the previous owner or look myself (how hard?)

Rand

Make sure it's not something simple like an exhaust leak.  They can make a sound similar to a knock at low RPM.

karneybo

is it can also be the cam chain tensioner and what your hearing is the valve lash.  Cbr f4 and f4I's the cam chain tesioner are known to go bad ( i know mine did ).
Carney