wr450f 2012 wont start cold

[joel0201]

Hi this is my first post, I have a wr450f which would start. At first I tryed to start a start it replaced the spark plug and after about 30min the engine warmed up and it started. I took it to the mechanic he had the same thing happened, he did a compression test and it was down by 30psi, and the piston and barrel was glazed and the rings where rounded. He repaced the barrel and piston and the compression went back up. Start first go warmed it up then we let it cool and tryed again and it wouldn't start, but it would start when its warm after kicking for ages, any ideas.

[OLHILLBILLY]

It's an ECU mapping problem. Buddy of mine has a '12 that he's Motarded, same issue, hard to start when motor cold, no start period when under 50 degrees. Do some reading and searching here.. https://www.thumpertalk.com/forum/12-wr-400426450/. Considerable discussion on the matter.

[joel0201]

Thanks, I'll try recalibrating it.

[R00ster07]

Hi this is my first post, I have a wr450f which would start. At first I tryed to start a start it replaced the spark plug and after about 30min the engine warmed up and it started. I took it to the mechanic he had the same thing happened, he did a compression test and it was down by 30psi, and the piston and barrel was glazed and the rings where rounded. He repaced the barrel and piston and the compression went back up. Start first go warmed it up then we let it cool and tryed again and it wouldn't start, but it would start when its warm after kicking for ages, any ideas.

your aware of cold start knob?    push /pull 

[R00ster07]

your aware of cold start knob?    push /pull 

i own 2013 wr450 ..   these bikes i think run a little lean .. i use cold start knob quite a bit .   even when warm sometimes

[FORMA MOTO]

Hi this is my first post, I have a wr450f which would start. At first I tryed to start a start it replaced the spark plug and after about 30min the engine warmed up and it started. I took it to the mechanic he had the same thing happened, he did a compression test and it was down by 30psi, and the piston and barrel was glazed and the rings where rounded. He repaced the barrel and piston and the compression went back up. Start first go warmed it up then we let it cool and tryed again and it wouldn't start, but it would start when its warm after kicking for ages, any ideas.

 

You have to seat new rings in the 1st 15 min, or it's too late

[joel0201]

The source of the not starting was the fuel pump, we reconditioned it an it starts first kick

[MidlifeCrisisGuy]

The source of the not starting was the fuel pump, we reconditioned it an it starts first kick

 

Tell me more.  What do you mean by "reconditioned it" ?  Clean the fuel filter in it ?

[joel0201]

Cleaned it dumped the fuel and made sure it was working properly

[joel0201]

Sorry it wasnt the fuel pump it was the injector module.