compression issue 99wr400, help would be great



8 replies to this topic
  • dan91

Posted December 22, 2013 - 01:26 AM

#1

did a top end rebuild on my 99wr400 yesterday new barrel, new piston,new rings,  head serviced, carby serviced everything went back together fine started ok but after about 20 minutes through the break in procedure the bike stalled and has lost some compression.. theres still some compression but doesnt lock up requiring the de comp lever like it usually does, just keeps kicking through and not starting , any help or ideas would be great as we plan to go for a ride next week

 

thanks



  • NEKOOHC

Posted December 22, 2013 - 01:32 AM

#2

Check the valve clearances

  • dan91

Posted December 22, 2013 - 01:42 AM

#3

sorry first time posting, left a few details out, valve clearences are spot on , timing on both cams is spot on to the mark on the crank at TDC,


Edited by dan91, December 22, 2013 - 01:43 AM.


  • 5valve

Posted December 22, 2013 - 05:14 AM

#4

behaves like stuck valve or decompressor.

 

Check if lubrication is working by unscrewing head banjo bolt and kicking, till oil comes out.

also try applying engine oil to cylinder wall, through spark plug hole. Sometimes it is needed to connect the oil film into compression.



Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • dan91

Posted December 22, 2013 - 11:44 AM

#5

behaves like stuck valve or decompressor.

Check if lubrication is working by unscrewing head banjo bolt and kicking, till oil comes out.
also try applying engine oil to cylinder wall, through spark plug hole. Sometimes it is needed to connect the oil film into compression.




Thanks mate I'll give that a try I don't think its the decomp .. Well it looks like its functioning properly on the out side anyway... Do you know a way to get the shit out from under the valves or do I need the head off again lol

  • dan91

Posted December 22, 2013 - 12:42 PM

#6

Anyone else got any ideas

  • dan91

Posted December 22, 2013 - 07:05 PM

#7

Still need any help I can get thanks

  • 5valve

Posted December 26, 2013 - 08:27 AM

#8

What would you remove under valves?
Did you try with oil



  • grayracer513

Posted December 26, 2013 - 09:10 AM

#9

You checked the cam timing AFTER it stalled?






 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.