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2016 YFZ450r SE Wont Start

8K views 4 replies 5 participants last post by  nadav2686 
#1 ·
Mods include an exhaust and vortext ECU. Already did some basic trouble shooting

Changed the spark plug
-put in a known working one and the quad still would not start

Battery swap
-tried jump starting the quad using a good battery

ECU swap
-took off the vortex ECU and put back the OEM yamaha ECU

Added fresh fuel to the quad
-only use 91 octane fuel, always have.

Checked the hose going from the tank to the engine
-was not clogged or torn


The bike was running really strong yesterday. After we stopped to take a break, the bike would not turn on. I tried to starting it for about 5 minutes and it finally started up. Continued riding for another 25 minutes or so. Turned the bike off again and this time it would not start at all! Tried rolling down hill to start it in gear and the bike did something i'd never seen... You could feel the engine running and pressure coming out of the exhaust but the bike would die immediately.

Something to note, the bike was sitting for about 3 months with no use HOWEVER when I went to start it for the first in 3 months it fired up in seconds with no issues at all. Got to the trails and again fired right up after being dead cold for a day. After putting back the factory ECU a check engine light started showing up, no codes at all, the light is solid then blinks until I stop trying to start it.

The only thing I can think of is the fuel pump. The quad use to make a purging sound when I would turn the key. Im assuming this was the pump priming the engine? I dont know. Is there something I can do to see if the pump is working or not?

Seriously if some is able to provide a fix I will donate $50 to you :grin2: would save me a huge bill at the dealer ;)
 
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#2 ·
To you what does "does not start" Mean? Lots lots of people say does not start and it means different thngs to different people. Do you hear any noises? Does the starter attempt to turn? Maybe valves out of adjustment. Maybe. Dead battery. Maybe a bad keyswitch. Maybe a bad fuze.

To me it means a lot of things: battery completely dead, does not even crank, weak battery, etc.... Key wont turn.
 
#3 ·
Very first thing to do, disconnect the fuel line at the fuel rail. Put this line in a Gatorade bottle or a bucket. With the electrical connector still attached to the fuel pump, turn the key on. Visually verify that the pump is priming or not. If nothing comes out of the fuel line, pumps not working (obviously) and at that point I would double check the fuses and the relays.

Are you good with electrical? I would find a wiring diagram if you can. I would also check to see if you have power at the pump when you flip the key on. I don't know which pin to check off hand.

Basically, if you have power at the connector, I would suspect the pump but I would also verify that by hardwiring the pump and seeing if fuel flows.

I'm not sure what the logic is with the pump priming, if it happens just on key on, or if there's something else to it.

Sent from my HTC One A9 using Tapatalk
 
#4 ·
my fuel pump every once in a while on my 14 wont kick on give it a quick smack to the side of the plastics and see if it primes. that is If you have power. im also a lil confused as to what you mean by not running.
 
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