Help!!


5 replies to this topic
  • YZ450F4

Posted March 25, 2011 - 02:17 PM

#1

Today i installed my new head pipe because the other on had cracked. i took it out for a ride and it was running great. just like it always has. i stalled the bike out and i was like you know no big deal. went to kick it and it has an a** load of compression. when you compression stroke it and kick it, it will kick back like a 2 stroke. Please help im clueless. it was just rebuilt 5 hours ago with new piston, cylinder, and stainless steel valves.
Thanks

  • grayracer513

Posted March 25, 2011 - 02:41 PM

#2

Start by checking the cam timing. If the chain was kinking, it could have backed over the exhaust cam when you stalled it.

  • YZ450F4

Posted March 25, 2011 - 05:20 PM

#3

its late so il have to check the timming tomorrow; however, i did replace the timming chain also in the rebuild

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  • howard113

Posted March 25, 2011 - 05:32 PM

#4

Today i installed my new head pipe because the other on had cracked. i took it out for a ride and it was running great. just like it always has. i stalled the bike out and i was like you know no big deal. went to kick it and it has an a** load of compression. when you compression stroke it and kick it, it will kick back like a 2 stroke. Please help im clueless. it was just rebuilt 5 hours ago with new piston, cylinder, and stainless steel valves.
Thanks


i hope with those valves you got the spring kit and i hope you got your valves seats cut.if not,those valves will wear way faster then they should and if you didnt get the right springs and stuck with oem,your going to have floating valves.....

  • YZ450F4

Posted March 28, 2011 - 10:08 AM

#5

the valves were pro-x and they came with springs. timing is right on the money; however, motor has metal shavings!!!! crank bearings

  • YZ450F4

Posted March 28, 2011 - 10:09 AM

#6

crank bearings starting to seize maybe?





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