2012 WR450F- HELP!

Hey guys,

First timer so go easy haha!

I have a 2012 wr450. I can’t figure out what’s going on with her. She will start but the second you even touch the throttle even the slightest, she will die. If you leave her idling for say 30 seconds to a minute, she will die on her own suddenly too.

I emptied the fuel and put new 98 octane in by the way. Another thing to note is I got a new air filter and I may have oiled it too much. But this occurs even with another air filter on it. Can anyone shed some light?

Edited by Sam Schirripa

blocked fuel pump filter by the sounds of it

Thanks Gary.. excuse the ignorance mate but how exactly do I inspect and repair that?

Take the pump out of the bottom of the tank to get access

Then search on here. Plenty of posts from Krannie about it with photos to show you

Thanks mate. Just an update. I had the bike shop pick it up and take a look for me while I was at work. Had a phone call an hour later saying she’s absolutely fine and running? I’m absolutely baffled as to why 12 hours before hand she wasn’t running at all! 

What did they do to it?

Intermittent faults are always the hardest to find and therefore solve


Still worth checking and cleaning your fuel pump filter though

They said the battery wasn’t holding charge so they put a jump starter on it. Then it started normally and ran fine. He said a stuffed battery can cause ghost like issues. Other than that, they did nothing. I’ll definitely clean that filter like you said mate.

3 hours ago, Sam Schirripa said:

They said the battery wasn’t holding charge so they put a jump starter on it. Then it started normally and ran fine. He said a stuffed battery can cause ghost like issues. Other than that, they did nothing. I’ll definitely clean that filter like you said mate.

Yes, if you are below 11v, the FI will not work properly. The stock batteries tend to die in the center cell.  Get a 12ah Lithium.

Thanks Krann.

As much as this makes sense, the issue still occurred when the new battery was installed. As my mechanic said "perhaps it had a ghost in it that night". But still from an engineering point of view, that doesn't settle with me. I will say that the relay adjacent to the battery I believe is on its last legs too. Perhaps this caused it. The new genuine one gets installed tonight.

On a side note Krann, I picked this bike up 3 weeks ago. It was in a 'less than desirable' condition with 7000km on it, and very dirty. Chain had seen better days and everything else was the same. Plastics were scuffed up bad, general dirty/grimey look and feel. Since then, I have stripped the bike, cleaned every external part of it, contact cleaned in every electrical plug, changed the spark plug, changed the battery, changed the oil & filters besides the fuel filter. My question is- Is there anything else I can be cleaning, replacing or inspecting to ensure the longevity of the bike and give it the good life it deserves? I will be doing the fuel filter like you suggested tonight.

Excuse the long post.. I just cant stand people who don't look after their machines so I'm trying to get it all perfect and get some confidence behind knowing it is going to serve me well for a few years.

I have attached 2 photos of before and after. It took me approx. 40 hours to get it looking like picture 2. Still a long way to go.


bike 1.PNG


The world thanks you for removing the black plastics.....

I would estimate you are at about 150 motor hours, so you should be at the very least doing a valve adjustment, but if the  bike was neglected on the outside, the inside will be just as bad.

Probably time to replace the timing chain,  chain tensioner, piston, and rings.  You can get 200+ hours on a stock piston, but if the PO only topped off his oil and did other shameful maintenence habits, it's worth checking into.

The OEM service manual provides service limit numbers for everything on the bike.

I would check some of the absolute basics.

Last start issue I had was a failed kill switch so you might just be getting a bad short in the kill switch circuit.

Thanks Kranny. 

I have measured the valve clearances and confirmed they are in spec. I don’t believe the former owner was too bad with the engine. Receipts show regular change with belray 10w 40. I’m about to clean the fuel filter with a light brush and shellite. 

The original issue was put down to a lazy starter relay. This relay also feeds power to the FI. It could have been feeding less than 12v and causing the problem.  

I have a 2012 with 200+ hours on it currently and haven't had any serious issues with the bike and have only needed to do the valves once. Here's my .02 on what I would check


1. Check you're idle - The "choke" knob is also the idle adjust. I've turned that thing more than a few times on accident. Making idle to low would cause it to stall.

2. Pull the tank w/the fuel pump still in it. Dump the contents into a bucket to see if you have dirt in the tank. Then remove the pump and clean it. I had sand in my tank when I switched to my 3 gallons but it never caused issues. Flush the tank with some gas.

3. Check to make sure there aren't any faults in your tip over angle sensor. If the bike is leaned over it will auto shut off after 30 seconds. Maybe its thinking its tipped over, or the sensor is damaged.

4. Us the GYTR power programmer to check for faults

5. Depending upon the temperature you're in it might just be due to the cold. When I am in temps above 50 degrees F. My bike starts like a champ under that you really have to make sure its warm before you can ride otherwise it will stall. My bike has done the same thing when it's under 50 degrees F, and you start it and then go right to giving it some throttle, it will just die

6. Check kill switch and clutch engagement sensor for faults.


I'd start there. In the six years, I've owned my bike the cold start issue has been the only issue I've ever had. So I don't think its anything major.

Hey man, just saw the post. I had the same issue. Pulled the plug out, there was moisture getting into the spark plug hole and the coil made a bad connection with the plug. When the bike heated up it got worse. New plug and clean connetions= bike runs fine now.

Filter your fuel before it goes into the tank! Last month I purchased a funnel withe the built in filter. I have been filtering twice. Once at the station filling my can and a second time when filling the bike. Probably an over-kill but the fuel is probably pretty clean from particle before hitting the filter.

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