Well I got the head back.....

6 replies to this topic
  • BC3

Posted December 18, 2005 - 07:37 PM


I picked up my cylinder head back from EDCO Thursday and put the YZ450
back together Saturday morning.....Started on the first kick...but I did notice that it was still popping through the exaust like it was the night at Sandhill Ranch practice session. I blamed it on the cylinder head problem but I guess
it was not the case.... :applause: It never popped before so I started my
detective work. The fuel is old and the slip fit may be getting loose on the pipe.
I sealed the slip connection on the pipe with heat proof silicone sealer and I'll
let it set-up for 24 hours and see what happens? What do you guys think is causing it, I already richened up the fuel screw by a turn and a half which helped but didn't stop it.....


  • 642MX

Posted December 18, 2005 - 07:42 PM


Some popping is normal, even with perfect jetting.

  • BC3

Posted December 19, 2005 - 07:02 AM


Hmmmmmmmmmmm its making me nuts.... :applause:

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  • grayracer513

Posted December 19, 2005 - 08:33 AM


Popping in the exhaust on decel is normally caused by either lean idle mixture and/or an exhast leak. The idle mixture should be set up to make the bike run right, not to keep it from popping. If you're sure it's rich enough to be proper, look at the exhaust. Also remember there are a number of things other than just the fuel screw setting that could make it lean, like an air leak, low float level or a partially blocked pilot jet.

  • Eddie Sisneros

Posted December 19, 2005 - 08:41 AM


sticking hot start.....

  • BC3

Posted December 25, 2005 - 12:14 PM


I haven't used the hot start lever for some time now (bike has been sitting)
And when I start the bike cold all I do is wick the throttle four or five times with the choke on and kick it once. Warm it up and just make sure it has some lube...
before I let it sit some more... :cry: So the hot start could have been stuck a
little :applause: I worked it a few times just to satisfy myself that it felt OK..
Popping seems to have slowed down a bit...richened up the fuel screw to about two turns out.....I think its leaking air at the slip joint on the pipe? Not much you can do unless I put a dorky clamp on the joint....I just let it pop.... :bonk:

  • hodgkins

Posted December 25, 2005 - 12:21 PM


merry christmas to you BC from the hodgkins.gotta sign off for a few to install the new cordless mouse.

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