Hello all,

I recently picked up a 99 CBR600f4 for a pretty good price; it rolled over 45k miles on my ride home with it. I have been enjoying the hell out of it for about 250 miles, but somewhere in there I noticed that there is a ticking noise when I let off of the throttle. The loudness and frequency of the noise seems to be correlative to the speed/RPM of the bike when I let off the throttle. The faster the bike the louder and more frequent the noise. At highway speeds it sounds more like a light grinding than a ticking at residential speeds. The noise sounds like it is coming from around the handlebars, but I could be off. It also stops when the clutch is engaged.

At first I was thinking that it might be the CCT, as it seems like these go out fairly regularly- especially on higher mileage bikes. After watching to a couple of videos demonstrating the problem, however, it does not sound like the same noise. Could it be the CCT just at a different stage of failure from the videos I watched? Or is it likely something different? I'd take it into the shop and have them take a look, but I figured that I'd check with you all first. Especially when money is a little tight between paychecks. Any thoughts on the issue would be greatly appreciated.

PS- I have noticed a small oil leak in the week or so that I have had it. Not sure if this would be related, but figured that I'd mention it. Oh yeah, and this is not just a lame excuse to never release the throttle!

 

sounds exactly like a CCT thing aside from the clutch thing you described. I would say you need to pinpoint where the noise is coming from exactly to help diagnose from there. Could pull out the CCT and just look at it to see if it is at full extension or not. Might be all out of adjustment. That would be a free and good check to start with

 

Could be the CCT but could also be valve-ticking. You can go a l-o-n-g time on a CCT w/ ticking but if its valve-ticking, I'd get it adjusted.

As for the oil leak, you need to determine exactly where its coming from & repair it asap. If its just leaking from the oil nut, the crush washer could be the culprit...replace & retighten.

Let us know how it goes.

 

If the grinding is speed related, check to make sure your front brake pads arent completely worn down or full of dirt or sand. And check for nasty grooves in your rotors also. Also could be wheel bearings. Lift the front end of the bike and check for play, and spin the tire as fast as you can and listen. If its rpm related, then listen more to where its coming from. If u can hear it more on the right it may be the cct. If its more under you or to the left, id think gearbox. But if it sounds like its in the upper end of the motor, it may be valves. Keep in mind is that our bikes do tend to have some valve noise at mid to high rpms, but shouldnt really tick. If you think it could be valves, try using a higher octane gas once. Could just be preignition from running too low of an octane value if your using regular at the pump. Hope all of this can help narrow it down a bit.. good luck!

 

Thanks a ton for the replies. I will try some of the things that you all have recommended tomorrow after work and more this weekend if nothing turns up then. I will also try a higher octane next time I gas up. I did not even think of that and have been absent-mindedly using 87. Does the manual call for higher? I think that whatever is causing the ticking is dependent on the bike being in gear as engaging the clutch eliminates the noise entirely. It is quite distinct. I'll try what I can tomorrow and keep you guys updated. Thanks again for the input!

 

I was thinking about it in the shower this morning and could it possibly be the chain? The one that I have on there is pretty loose and is going to be replaced along with the sprockets this weekend. My only other bike (CX500) was shaft-driven so the chain was kind of in the back of my mind. That would explain the absence of the noise when the clutch is engaged, right? Would a wearing chain only make noise when coasting or would I be hearing this when accelerating too?

I might bump up the chain replacement to sometime this week just to see if it might be that. Either way, I'll let you all know how it turns out. Thanks for the continued help.

 

87 octane is sufficient.

Change out that chain & sprockets & let us know how it goes. Take your time & do it right. Get a good quality chain, such as RK or D.I.D - both are OEM suppliers. Be sure to use a proper chain tool & flare the master-link pins to spec.

 

87 octane works fine. however, some bikes are slightly more picky than others. i know my bike sometimes has a slight stumble when im at a steady speed in town, but when i mix in a half gallon of race fuel to a tank of premium that stumble is gone. and yes, that could be the chain if it sounds like its more under or behind you. chains are going to make some noise, as my new chain and sprockets can still be heard. and it may mostly go away when you engage the clutch due to the tension being taken off of it.

 

I put on the chain and sprockets today and took it for a spin. The noise is gone entirely. Looks like it was just a case of a very worn chain and very poor sound isolation on my part! Thank you all for the help- I'm on to checking out the oil leak this weekend.

 

thats great! can you tell at all what general area the oil is coming from? if its coming from the back side of the motor, double check the cct. if the bolt on the end of it is loose or missing, that can leak pretty good. also, if the oil was overfilled, it can work its way out of the intake up top and run down the motor. those would be the simple fixes id check first.