Wrf450 full top end rebuild won't start, do I need I change jets ?

7 replies to this topic
  • Joeturabian

Posted July 11, 2013 - 04:19 AM


Hey everyone, have an 06 wrf450 that I have just replaced piston, had cylinder rebored, all new gaskets and had valves reshimed. I have done the timing perfectly to spec but it won't start just backfires. I have also flipped the crank 180 degrees and tried that but no difference, also hooked up my battery to my car for extra juice as it was a bit flat. But still nothing not even the slightest bit of life. Has plenty of spark, could this be a jetting issue now ? Everything else is the way it's supposed to be I don't know what it could be

  • DrFeelGood

Posted July 11, 2013 - 04:43 AM


Have you checked all of your vacuum lines? Has the AIS been plugged off?

  • Joeturabian

Posted July 11, 2013 - 04:54 AM


The vaccum lines on the rocker cover ? Could that cause it not to start ?
Also I live in australia I don't think the bikes have ais

  • Krannie McKranface

Posted July 11, 2013 - 05:11 AM


No need to change jetting.
How long has the bike sat?
You may need a new pilot jet (corrosion)

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  • Joeturabian

Posted July 11, 2013 - 05:23 AM


Sat for over a year, carby was pulled apart and it all looks good

  • aussieklx

Posted July 11, 2013 - 05:38 AM


Triple check cam timing.

Then check it again.

Then get old mate next door to check it....

Did you replace timing chain?
Did you have good continous spark? Tried roll start?
With good spark and fuel it will run, albeit shithouse if incorrect jetting. Which points to cam timing

Edited by aussieklx, July 11, 2013 - 05:39 AM.

  • grayracer513

Posted July 11, 2013 - 10:43 AM


Sat for over a year, carby was pulled apart and it all looks good

No chance. OK, a chance, maybe, but I doubt the carb's good after all that time. Dump the old gas, too, if you haven't already. The pilot jet is exceptionally small, and the slightest coating of varnish in the jet orifice or the passageway leading to the air stream can significantly change the effective size of the orifice. A number 45 pilot is .45mm through the metering passage. That's just over .017". A film of varnish no more than .002" thick effectively turns a #45 into a #35. That changes things...a lot.


  • Joeturabian

Posted July 11, 2013 - 09:34 PM


Gave it a push start, fired right up :D


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