my 954 ive been having problems with since i rebuilt it and i just want to cry. i just found out that if i open it all the way from idol it dies? i swear the only thing i havent done was change the plugs lol
cbr stall - YouTube

 

dude, what is that piston/cyl wall gap? have you done a compression test?






i hate to tell you this. i'm so serious, from the bottom of my heart, i hate to tell you this.




but that thing is a time bomb right now.




and i only say it because i've been there on 2 954 motors.... that knock was identical on both of them to yours in the vid. and it was piston/cyl wall gap. and it sucks, because there isn't a whole lot you can do without spending tons of money (if that's what it is). do you have a stethoscope you can listen to the motor and pinpoint that knock? you say you re-built it, did you actually take the motor apart?

 

no i never did the motor,w i re built the bike itself , new motor swing arm subframe..... i wrecked a couple years ago and destroyed the bottom case. now wen you say knock you mean the tapping befor i rev it? because i've been trying to figure it out and i think its coming from the head but im not sure havent used a stethscope. couple guys told me bad valve or adjustment. in the video thers a noise that sounds like a knock but its miss fire, it miss fires then dies. couple pops like its starving for fuel then cuts off

 

Sounds like a fuel delivery problem to me. I would guess one or more injectors not working correctly, or the computer not giving the signal to open the injectors soon enough.

 

years ago i had a ford ranger do something simular, if i gradualy hit the gas its fine but if id hammer it, it would die and it was the fuel pump didnt have enough pressure. now i have another 954 how would i go about changing the injecters? take the whole throttle body off? could i just clean them?

im going to try making a better video today conrice has me scared lol

 

was there fuel sitting in the tank a long time?


the fuel filter is inside the tank on the pump. you get to it by taking those little 10mm nuts off that are on the bottom of the tank.


as far as the injectors, you don't need to take the TBs off, just get the airbox off, and then there are 3 or 4 8mm bolts that hold the fuel rail and injectors onto the TBs.


clean everything with carb cleaner.




as far as my first post - best of luck to you... but... that's not a top end noise. in fact, when the valves need adjustment - they usually don't have a noise - and definitely not one like that. valves gap usually decreases, meaning the cam and bucket get closer together because of carbon build up - which doesn't cause any noise. a lot of people throw around the term "valve adjustment".

your rings are eventually going to give and you'll lose compression and you'll constantly misfire

 

so i went to make a better video and its not stalling when i open it anymore? maybe cuz i had the tank off prier? but here the video i made so you can hear my tapping, does it at idol tell me what u think

954 tapping - YouTube

 

as far as what anyone on here could advise, don't hold the camera so close to the motor, hold it a little further away and towards the front of the bike (mainly just not by the exhaust pipe).



but the only real way to tell is to get yourself a stethoscope and start trying to pinpoint it.
Mechanic's Stethoscope Use To Locate Trouble Spots In Engine Block




it's much more apparent in that first vid as opposed to your second vid that you just posted and i think it's because it's too close to the motor so we're hearing too many other noises.


if it is piston slap, it would *sort of* (and i'm using that term lightly) go away as you added some rpms because of the inertia of the piston. it's a problem with these bikes because the skirt on the piston is so small so we can do the high rpms. you'll not be able to really pinpoint the noise except for a half inch or so under the head on the block and it should be on all the cylinders typically.


if it's in the head, you'd notice the noise above the exhaust pipes (for reference) - but i sincerely doubt it'll be there


if it's a rod nock or something, you'll pinpoint it to one cylinder and it'll be very prominent and it won't go away at all with rpms.

if it's in the tranny, you'd hear it further back towards the rear of the bike - but noises in the tranny are usually very intermittent and come and go. i don't think it's that either.

 

My bike had the same noise. I have just pulled the head off the motor and all four pistons rock back and forth, and the bore is scored on the fore/aft side of the cylinders. The bike has an indicated 40000km's on it. Hopefully I can rebore the cylinders within the 0.25mm oversize and remove the scoring or I will have to get each cylinder replated as well. All in all a lot of stuffing about.

I have not checked to see if it is a bent valve yet.

Conrice: Did your pistons rock on all four cylinders, yet sound like just one cylinder ticking like in the videos?

 

srry but i made another 1 u can hear REALLY GOOD! i wanted u to hear it rev b4 so i had to stand next to and thought u could hear it better closer to error. but check this video out and hit me with the bad news i will get a scope, i used to use wood lol and ill have more questions about the orange 929 motors locked up. thanx alot evryone, i worked in shops for years and that why i dont trust them and dont want someone elses hands on girl or i would just take it somewer and say here rip me off and scratch it up and say it was like that. so thanx alot everyone!

tappy tap2 - YouTube