I have a 94 cbr f2 with about 29,000 miles I was riding with a buddy and I started noticing a loud knocking noise coming from the left side of the engine it increases with engine rpm. When the bike is idling it sound fine until about 2500 rpm's then it's a moderate knock and after you get to about 4000 rpm's it's extremely loud and there's a noticeable power loss. So knowing the problems with the stock cct I checked that first even though the sound is on the other side of the engine, when I turn the motor over by hand there is one spot where the cct retracts by itself them pops back out with a couple mm of a turn. I would imagine this is normal considering there's no oil pressure to push the tensioner out. There is nothing wrong on the top end no broken lifter springs, bent valves etc and I have 125 psi on every cylinder. Can somebody please tell me what to look for to find this damn noise it's annoying and I'm afraid that I'm going to ruin the engine by running it

 

If it were a car engine I would say a rod knock from a spun crank bearing.

 

ya it sounds like you spun the crank bearing like i did my good man

 

Did you get yours fixed ?


Does anybody know how hard is it to split the case and replace something like that and what kind of damage to the engine it might have done. I can do the work myself i just dont know what to look for when it comes to the bottom end of a motor.

 

I did this, Step 1: buy new motor, Step 2: split both cases and take transmission out of my motor and put it in new motor. step 3: put back together. (insert in bike and call it a day) Its to much work to rebuild this old *** motor not worth it

 

I agree.........there are used engines on ebay.

 

Does anybody know if a f3 engine will bolt up in my f2 without having to change anything

 

It's been done - do a search on the forum and you will find multiple threads regarding this...from what I remember, it will require everything from the F3: engine, carbs, wiring harness - not totally sure what else, but if you search the forum, you'll find the answer.