2010 yz450f sputtering

hey guys just installed a new spark plug yesterday because i was guessing the kid i bought it from last year had never done it and not much to my suprise the thing was nasty. even rusted. So i installed a new one ngk standard and did a quick oil change. Got everything put back together and was really looking forward to the first ride of the year up here in north dakota and now the bike is sputtering really bad when i was riding it. The first start up was fine and it idled nice just to get it running after the oil change. The second start up it did not for the life of me want to start. I finally got it started and went on my way. It started sputtering right off of the bat and didnt want to stay running and it was backfiring. Im not sure if the new plug got messed up on its way down the hole of if by some weird chance the fuel line under the tank got pinched upon reinstallation. Anyone have any advice or had this happen. I wont be able to get back to work on it until sunday so looking for some advice in advance. thanks 

Fuel filter needs to be checked and if it's black search this site on how to replace the filter only and not have to buy the whole oem part

u might have had some really bad gas as well

Ya that's what I have been hearing a lot of. It won't be until Sunday that I can check it. The u motors here in town wants like 450 for the oe part but he also told me that my bike had a carburetor and yamaha didn't come out with fuel injection until 2014 so who knows what he was looking at

That guy needs a new job busing dishes.  EFI came out in '10 on the YZ450. 


If it ran alright before you changed the plug, you may also want to verify that you haven't unplugged something along the way.

That is very sketchy!

There is a you tube video of a guy doing a filter change and a thread or 2 here that will help a ton

The filter is hard to access on the pump assembly however you can do it !

Will post later tomorrow on what I find. Going to dump all the gas and take the pump assembly out and apart to inspect and I got a couple more plugs so I'll recheck everything from that aspect as well.

The filter is almost impossible to see without taking apart the fuel pump.  I just did mine on my 2011 a couple of weeks ago.  Would have taken some pictures, but I was fumbling around trying to figure it out myself so I don't know that pictures would have really made sense.  But there is a thread on here with some good information.  


You will need to have a couple of picks and some small flat screw drivers to take it apart.  The entire pump is like 5 or 6 pieces that basically snap together.  Sounds easy, but it's not.  The clips are all one way and you have to really persuade them to come apart. Most likely a shop is not going to take the fuel pump apart for you, because that is not how Yamaha designed it, so you'll have to take the gamble on your own and do it.  It is possible if you take your time.  


On a different note, immediately stop going to that shop...  Unless the guy behind the counter that you talked to is just a once off, I would stay away from them for sure.  OE pumps are not $450, they are $340 from RMATV.  This guy clearly doesn't know what he is talking about.  




Here's the link to the thread.  There are some pictures from MONK when he did it.  



Edited by cpetz24

Thanks for the link that will help. I watched a video but he had everything apart already for the video so it didn't help at all with the clips. The only reason I go to the shop is because they are the only ones around that sell yamaha parts if I need them right now

Quick question what do you guys think about those twin air fuel filters. Seems like a good idea for a little extra protection

Do you mean an inline filter, or the sock that goes down in the tank that filters you're fuel when you pour it in the tank?  An inline filter will do you no good. 

The sock that goes in the tank to filter as you gas up. We'll I did get the pump assembly apart and first let me say that yamahas designer of that assembly needs to be punched in the face. With that off my chest let's move on. The fuel filter was just black. Cleaned it out put in a new spark plug put in some fresh gas and just a little seafoam to clean everything else a little bit and after riding for about 20 minuts everything smoothed out and it's like new again. Still going to order a new pump and filter cause the filter is still not perfect but I had lots of fun this afternoon. Thanks a lot guys!

Also what is the best place to buy one of the fuel pump kits. I have found a few but haven't heard of any of the websites before

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