2008 fz1 knocking sound at 4k-5k motor has 10k in it

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BigNastyBRP

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Hello all I just replaced my 2002 fz1 and I rode it for 80k. so I sold it and got a 2008 with 9400 miles. right after I got it I heard knocking at 4000 to 4800.
I have been going nuts trying to find it. I think its rod knock after noticing the sound now I can hear it at 2k to 3k but very quite not like at 4 to 5k.
the bike has a full pipe so no exup bike has good power and the oil looked good, no crap in it. The sound is made with the motor under load only.
I checked the stator and it looks great, I have a cam chain tensioner on order I hope that's it or I just paid $4500 for a bike with a bad motor. any thoughts on what it could be on this low mile bike. thanks B
 
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There are a couple of mechanics around so hopefully they will chime in (I'm not a mechanic). My thoughts are that Cam-chain slap from a bad tensioner would be most noticeable at lower rpm, but it isn't a "knocking sound". My bike has an oil pressure cam-chain tensioner and it makes more of a rattle until the oil pressure tightens the tensioner.

Without tearing the engine right down I doubt that you can know for sure. You could have an oil sample analysis done to see if anything is wearing that doesn't show visibly in the oil.

Other possibility; main bearings or crankshaft have wear, allowing a bit of "slop" when under load??
 
It sounds awfully familiar to the cam chain tensioner issues many Hondas are plagued with. My VFR has the same issue and I've got some new cam chain tensioners ready to go in :)
 
I used a stethoscope and was not able to hear anything odd but it is just idling I think I need to get it on a dyno and try again. Thanks for the input so far guys.

under load I.E. rolling on the gas in gear going down the road or holding the front break and giving it some gas. put load on the engine.
I can be a 4k have the sound and let off the gas and the sound is gone but if I give it gas its there again. I will pull the tank and check the filter and that area next. I repacked the pipe last night so thats not it.
 
i've had 2 cam chain tensioners go out, similar sound as described but, without hearing it, who knows. take video of sound perhaps? however, a dyno tuner worth their salt should be able to tell you exactly what it is immediately
 
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