98 yz 125 top end breather tube!my bad i posted in the 4stroke section

98 yz 125 top end breather tube
 
125yzrider
New User | Posts: 5 | Joined: 01/09 Posted: 01/10/09
10:16 PM
breather tube coming from top end/piston casing is pushing out exhaust! is this normal?  


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yzrider2
Guru | Posts: 1207 | Joined: 04/08 Posted: 01/10/09
10:25 PM
i have a 98 mine dosent do that is it smoke  
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125yzrider
New User | Posts: 5 | Joined: 01/09 Posted: 01/10/09
10:32 PM
it smokes a little on start up just like the exhaust. thats how i noticed it. still though i can put my hand over the tube and it is definetly popin out air/exhaust everytime it turns over  


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92rm125
Addict | Posts: 6237 | Joined: 03/08 Posted: 01/11/09
01:36 PM
Exhaust valve is gummed up.  
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125yzrider
New User | Posts: 5 | Joined: 01/09 Posted: Yesterday 12:35 PM
thanks i did some research and found this out. would this exhaust valve have anything to do with there being no bottom end on the bike? i know 125's are top end bikes which once i get into my top end this bike screams. once i stop and kill the engine to get it started again i have to open the throttle wide open, like its flooded or something which its not. would all this be related to the exhaust valve?  


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92rm125
Addict | Posts: 6237 | Joined: 03/08 Posted: Yesterday 12:50 PM
I dont think the exhuast valve is connected to that issue.

Have a read of this:

http://forums.dirtrider.com/70/7293535/frequently-asked-questions/jetting-faqs/index.html

Does your bike do any of the syptoms described?  
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No pain; No gain

   
125yzrider
New User | Posts: 5 | Joined: 01/09 Posted: Today 10:36 PM
thanks for the info. did a compresion check on  it. checked out at around 125. i hear that 150 is good and 80 you need to do a top end. i am going to check the carb! air/fuel mixtue screw,jetting, and needle. also clean the exhaust valve or maybe pick up a new one if it is possible?  

no 145 is about the lowest you want to go i would do a top rebuild
DavidS  
i take a lot of pride in what i am

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local: north east Oregon

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what do tou think obout the exhaust valve being gummed up? would this effect the bottom end? like i mentioned top end screams but low end is bogged out. after ride'in for a while once bike is warm, and i kick it over it needs to be  wide open to start!  

i HAVE A 98 yZ 125. my bike is doin the same thing. i have noticed that i dont really have much bottom end power. i live in southern maryland and i rode the my bike to day in the cold ( about 19 degrees) besides my hands freezin off the bike keep shuting off. i would pull the plug and it would have alot of oil on it. now when the motor was hot it wasnt hard to start. could this be a jett problem? i have just redone the topend and i dont think i have 140 psi in the topend. do i need to lean out the jet?  

Killian you need to start a new thread.  
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