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Hard starting,stalling,backfiring 450

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I have a 2005 wr450f that had some issues with a bad stator and magneto. 

I replaced the stator with a trail tech.  Replaced the mag with oem. Replaced the rectifier with trail tech. Wired up per instructions. 

Rebuilt carb. Valves shimmed in spec. Charged battery. New carb boot. No exhaust leaks. No leaks at hot start. New adjustable fuel screw. 

Bike will barely start and will idle for about 10sec then shut off. When revved it shoots flames out exhaust. I have tried every jetting combo possible. I did the o ring mod on accel pump. Im about to set it on fire. 

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Sounds like a bad stator.....or an arcing wire harness/plug cap/plug coil......or, if the timing chain and tensioner have never been changed, a cam that has jumped timing...

 

Edited by Krannie McKranface

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21 hours ago, strokemetwice said:

I have a 2005 wr450f that had some issues with a bad stator and magneto. 

I replaced the stator with a trail tech.  Replaced the mag with oem. Replaced the rectifier with trail tech. Wired up per instructions. 

Rebuilt carb. Valves shimmed in spec. Charged battery. New carb boot. No exhaust leaks. No leaks at hot start. New adjustable fuel screw. 

Bike will barely start and will idle for about 10sec then shut off. When revved it shoots flames out exhaust. I have tried every jetting combo possible. I did the o ring mod on accel pump. Im about to set it on fire. 

 

There seems to be some terminology issues here...

These bikes do not have magnetos...   They have a stator and a ignition pulse pickup coil.   

These two pieces are normally changed together, if you changed the stator to Trailtech, then the whole works should be Trailtech unless you cut open the wiring harness and changed them separately.

You can only use the Trailtech regulator with their stator... OEM will not work.   However, regulator has nothing to do with your symptoms.

The problems Krannie mentioned are the most common causes of those symptoms.   The failure of the ignition pulse coil is a more common culprit than the stator though. 

 

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13 hours ago, DeepPurplishBlue said:

 

There seems to be some terminology issues here...

These bikes do not have magnetos...   They have a stator and a ignition pulse pickup coil.   

These two pieces are normally changed together, if you changed the stator to Trailtech, then the whole works should be Trailtech unless you cut open the wiring harness and changed them separately.

You can only use the Trailtech regulator with their stator... OEM will not work.   However, regulator has nothing to do with your symptoms.

The problems Krannie mentioned are the most common causes of those symptoms.   The failure of the ignition pulse coil is a more common culprit than the stator though. 

 

Yes all trail tech stuff. Iwas reffering to the flywheel when i said magneto. Sorry about that. Pickup coil is trail tech. The only thing i can think is the carb slide rubber seal maybe going bad. That hasnt been replaced. I read somewhere that could be causing this sort of issue

Edited by strokemetwice

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Cant find any vac leaks. Im giving it back to the guy im working on it for. First bike that i have ever not been able to make run properly. This bike broke my spirit.

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