noisy yx

[TDR]

Hi guys

my yx 150 (with tb 170 kit tb v2 head) has been really noisy
so far i can say it has nothing to do with the head i have taken the head off and turned the piston over while it is in the cylinder and it is still there.
it only happens with sudden movement but if i put my fingers on the piston to create resistance it no longer makes the noise. so im thinking it could be the big end on the con rod. BUT i took off the cylinder removed piston and the
con rod seems to have little movement if any and no sound when pushing and pulling it
i recently blew the top end (piston) cylinder had no damage what so ever no idea how it didn't get destroyed and the bottom end was fine from what i could see. this noise was there before this had happened only thing i can think of is the bearings but again if we turn it over without cylinder on and piston its quiet as anything which makes no sense at all to me

i have posted a video of me turning the motor back and forth from the irk so you can hear the sound it is pretty loud and sounds terrible when running it is a knocking sound and once again it is not the head or cam because it makes the noise with the head off!

if you guys could possibly share what you may think it is that would be great

VIDEO:

<iframe width="420" height="315" src="http://www.youtube.com/embed/BE7vszKratY" frameborder="0" allowfullscreen></iframe>

 

[SwapperMX]

With everything that you have posted, and with a noise like that, I would be pulling it down completely and splitting the cases. There has to be something very wrong with it. It should become a lot more obvious once you have pulled it down.

 

[TDR]

i have pulled it down like i said after doing the top end and i done a big clean up and checked over all the gears etc and was clean not one fault this sound was there before i pulled it down aswell
and has only became worse

 

[SwapperMX]

It sounded to me in the first post that you only pulled the top end off. That noise obviously indicates that you have a big problem. And it sounds like it is going to be in the bottom end. Have you split the cases??

 

[TDR]

i have split the cases when i did the top end just after Christmas reason why: peaces of piston dropped down to the bottom therefor it needed to be clean and needed to check all the gears for wear. i cleaned it out looked closely at everything it was all good

"i recently blew the top end (piston) cylinder had no damage what so ever no idea how it didn't get destroyed and the bottom end was fine from what i could see."

there im trying to explain that i have looked through the bottom end and nothing was wrong from what i can see everything was fine and this noise was way before i even blew the top end like i said.

i posted this thread to see if anyone has had a problem like this or been through it before and then they could share things they could believe it would be

i have pulled down this engine so many times now its ridiculous im not going to pull it down again to find nothing that's why i want people to have there input on what it may be then ill think about it and the possibility of it causing the noise and might pull it down and if i get no reply then ill just get the z160ho because this things allot of trouble to keep working

 

[SwapperMX]

i have split the cases when i did the top end just after Christmas reason why: peaces of piston dropped down to the bottom therefor it needed to be clean and needed to check all the gears for wear. i cleaned it out looked closely at everything it was all good

"i recently blew the top end (piston) cylinder had no damage what so ever no idea how it didn't get destroyed and the bottom end was fine from what i could see."

there im trying to explain that i have looked through the bottom end and nothing was wrong from what i can see everything was fine and this noise was way before i even blew the top end like i said.

i posted this thread to see if anyone has had a problem like this or been through it before and then they could share things they could believe it would be

i have pulled down this engine so many times now its ridiculous im not going to pull it down again to find nothing that's why i want people to have there input on what it may be then ill think about it and the possibility of it causing the noise and might pull it down and if i get no reply then ill just get the z160ho because this things allot of trouble to keep working

Fire up buddy. I was trying to help. If you used some punctuation it might be a little easier to understand what you have written. The way that the earlier posts read, it sounded like you were looking at the bottom end by just taking your barrel and head off. :boxe:

 

[sm00th]

Sounds like the big end is flogged out. Time for a new crank

 

[TDR]

Sounds like the big end is flogged out. Time for a new crank

yep spot on or close enough! just pulled off the clutch today so when i turn the slinger only the crank moves and the noise is still there so splitting cases next week and buying a new crank and going to shim all or most of the gears while I'm at it

 

[sean01]

could be several things...

stuffed chain chain tensioner
missing or damaged bottom chain guide
top guide could have issues as well...

did you inspect the can chain tensioner..
pull the cam gear cover off and do the same thing with the socket on the crank and see if you can see the cam chain slapping, probly wouldnt hurt to pull the stator plate off too as then everything is exposed for viewing...

also you say a 170 kit, it it the tb kit and is this the long piston version.

some sounds/clunks in an engine can sound to be coming from one area but infact the sound can travel through other components so it could be excessive backlash on the primary crank gear to the clutch gear, sht it could even be the clutch rubbers shot...

start pulling it apart after you've done wat iv said above and inspecting bit by bit till you have an answer...

one other thing... you say it not the head.. does this mean that the noise is still there while the head is off???
could it be piston hitting the head or even the rocker gear shaft plate bolts come loose and hitting the cam gear...

 

[sean01]

could be several things...

stuffed chain chain tensioner
missing or damaged bottom chain guide
top guide could have issues as well...

did you inspect the can chain tensioner..
pull the cam gear cover off and do the same thing with the socket on the crank and see if you can see the cam chain slapping, probly wouldnt hurt to pull the stator plate off too as then everything is exposed for viewing...

also you say a 170 kit, it it the tb kit and is this the long piston version.

some sounds/clunks in an engine can sound to be coming from one area but infact the sound can travel through other components so it could be excessive backlash on the primary crank gear to the clutch gear, sht it could even be the clutch rubbers shot...

start pulling it apart after you've done wat iv said above and inspecting bit by bit till you have an answer...

one other thing... you say it not the head.. does this mean that the noise is still there while the head is off???
could it be piston hitting the head or even the rocker gear shaft plate bolts come loose and hitting the cam gear...

 

[TDR]

could be several things...

stuffed chain chain tensioner
missing or damaged bottom chain guide
top guide could have issues as well...

did you inspect the can chain tensioner..
pull the cam gear cover off and do the same thing with the socket on the crank and see if you can see the cam chain slapping, probly wouldnt hurt to pull the stator plate off too as then everything is exposed for viewing...

also you say a 170 kit, it it the tb kit and is this the long piston version.

some sounds/clunks in an engine can sound to be coming from one area but infact the sound can travel through other components so it could be excessive backlash on the primary crank gear to the clutch gear, sht it could even be the clutch rubbers shot...

start pulling it apart after you've done wat iv said above and inspecting bit by bit till you have an answer...

one other thing... you say it not the head.. does this mean that the noise is still there while the head is off???
could it be piston hitting the head or even the rocker gear shaft plate bolts come loose and hitting the cam gear...

yep its the 170tb kit and yes it does it with the head off we had a look at the chain that is fine we took out the tensioner and noise was still there chain is fine and not slapping i pulled stator off yesterday had a look at the timing chain gear that is fine we took off the clutch so when we turn the crank the gear box doesnt move so only thing it can possibly be by rights now is the crank either the big end or the bearings but bearings usually scream there heads off when there broken so might not be that.

so this weekend we will pull the bastard apart and see whats up with it this time

thanks for the good reply i appreciate it

 

[sean01]

no worries.

time for a 57mm or even 55mm crank lol

 

[TDR]

Fire up buddy. I was trying to help. If you used some punctuation it might be a little easier to understand what you have written. The way that the earlier posts read, it sounded like you were looking at the bottom end by just taking your barrel and head off. :boxe:

just saw your post sorry lol.

and yes i know i was being a **** and im sorry.

i was having a really ****ty day and yeah i shouldn't of let it out on you and i apologize for the crappy grammar ill try my best next time to make it more readable lol.


and guys I'm also wondering what can i do to give it a longer life.

I'm already going to shim everything, I'm thinking off replacing all bearings with ones from a bearing shop? I'm guessing there better quality, or no different?

I'm not to keen on changing crank sizes then needing to change the barrel etc as i just want to keep the engine set up, but just want it stronger.


I've probably pissed you all off enough as it is i just really want to be able to come home from riding at least 3 weeks without needing to replace something ( a bit overboard but that's what it feels like )

thanks

 

[TDR]

ok everyone just like to say thanks for helping me out and giving me ideas i appreciate it allot

i found the problem and was piston slap so just ordered a new TB170kit with piston and barrel etc so should be all good now