Am I just paranoid?

4 replies to this topic
  • rmcr250r

Posted October 15, 2010 - 04:24 PM


So i just got done adjusting a valve on my 09 yz450f. (middle intake measured at .09) This was the first time ive ever done this. I followed the manual step by step. Removed the cam as per manual and torqued to specs. Installed shims correctly and checked timing. I thriple checked everything before putting the valve cover back on. Also did some jetting working while it was apart.

So after the reassembly i started up the bike. Took a good amount of kicks to get started. After getting it started it seemed to run well. No popping or backfiring. However the cams did seem noisy and i cant really remember if thats how it always sounded. Also, the bike didnt really wanna start back up again after it was warmed up. Is it possible thats a jetting issue?

So once again took the valve cover off and checked the valves and timing and everything was perfect. Am I just being a little paranoid or is there a good chance i might of messed up somthing.(like warped the cam or somthing)The last thing i want is the bike to blow up because of my stupidity. Any advice would be greatly appreciated.

  • MARQUEZ_697

Posted October 15, 2010 - 04:38 PM


some noisiness being noticed is from you are now listening for it while before you werent. pull the timing plugs, take a socket and turn the motor over by hand with the valve cover off, watch the cams as they rotate and also listen for piston slaping the valves or any parts where the cams are binding. it will feel different from compression.

more then likely if you can still kick it over, you didnt warp the cams or bend the cam caps. if you did it would be damn near impossible to kick it. (i tweaked my cam covers last time and it literally held me up in the air wen i tried to kick it).

if everything looks good and theres no weird sounds wen the motor turns over without it running i would say its just you being paranoid.

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  • rmcr250r

Posted October 15, 2010 - 04:53 PM


just turned the motor over by hand and the only noise i hear is air from the decompression mechanism on the exhaust cam. What would explain my starting issues? rich jetting? I only richened the needle cause before it felt like a lean condition. But upon disassembly i found a major exhaust leak between the header and silencer.

  • MARQUEZ_697

Posted October 15, 2010 - 05:18 PM


if you had an air leak but fixed it then your bike is now running rich. air leak caused the bike to run lean, you jetted it for the mixture with the air leak, if you fixed the air leak then your old jetting would now be correct. but since you changed it i would recomend changing the plug, setting your jetting back to what it was, make sure wen you go to start it gently kick the kickstarter until its at the top of the stroke and then see what that gives you. my guess is it will start on the first 5 kicks. if cold make sure your choke is on, once started turn the choke off.

  • rmcr250r

Posted October 16, 2010 - 07:50 AM


Anyone else have any input that will lead to my peace of mind.

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