Stumped & Chasing My Tale

Hey guys,

Need some help with my 450X which has me scratching my head. When under 175 degrees my 450X runs great. Once it starts going above 175 the bike starts popping, backfires, feels like it's being starved of fuel then dies. The electric start just cranks and it will only fire back up with the kick starter. Idle rises then falls until it stalls. Tokyo Mods just cleaned the carb, installed all new fuel lines, made sure the overflow tubes weren't clogged, and installed a new plug. I am at a loss besides thinking the ignition coil or stator are beginning to fail. 

What do you think?

Do your fuel lines run near a heat source?  It sounds like when it gets hot the bike is leaning out.  If your fuel lines get too warm the fuel can vaporize in the line which starves the engine of fuel.  The popping, backfire, and rising idle and stall all sound like a lean condition.  I would start by checking where your new lines are run.

Thanks for the input. I replaced the lines with OEM part numbers although getting insulation for them is a great idea. I'll pick some up at a local auto parts store. 

Thanks for the input. I replaced the lines with OEM part numbers although getting insulation for them is a great idea. I'll pick some up at a local auto parts store. 
hot start stuck?
5 minutes ago, KEITH OLSON said:
On 1/27/2018 at 1:38 PM, BDTRENT said:
Thanks for the input. I replaced the lines with OEM part numbers although getting insulation for them is a great idea. I'll pick some up at a local auto parts store. 

hot start stuck?

I removed the level actuated hot start and installed the plunger type off a CRF/R to cleanup my handlebars and cables. I could have installed the new mechanism incorrectly. I will check when I get home. 

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