Won't start - '15 WR450f


21 replies to this topic
  • easystreet

Posted December 13, 2015 - 02:07 PM

#1

Bike ran fine about two months ago when parked. Only has about 15 hours run time on it. It just cranks and cranks never catching or getting any run attempts. I pulled the spark plug out and grounded it. I have strong spark. I sprayed some starting fluid into the plug hole and a little into the intake. Still won't even briefly run. I put a compression tester on it with the throttle wide open I only get to about 30psi. I know the auto decompression will affect this, but not sure it should be that low. What I believe is the TPS on the left side of throttle body appears to be where the factory paint marks were initially. 

 

I'm stumped here guys. Has anyone had one of these jump timing while trying to start? I can't think of what else would cause a no start when you have spark and manually insert a fuel. My next thought is to pull the valve cover and check timing alignment. Would rather not if I should try other things first. 

 

Greatly appreciate any feedback!



  • gripitnripittx

Posted December 13, 2015 - 02:25 PM

#2

It's fuel injected, have you checked to ensure the fuel pump is operating, you can usually hear it pressurize when you hit the ignition button (not the starter button)

  • easystreet

Posted December 13, 2015 - 02:51 PM

#3

It is fuel injected and I do here it prime when turned on. 



  • Krannie McKranface

Posted December 14, 2015 - 06:18 AM

#4

Old gas

Corroded injector nozzle from old gas corrosion

Tip over sensor failure



  • NH856

Posted December 16, 2015 - 10:00 PM

#5

Make sure the spark is at the tip of the spark plug as well, otherwise can have issues igniting

  • easystreet

Posted January 18, 2016 - 07:54 PM

#6

Update:

I went out again today to try and get this thing running. Still the same. 

 

I plugged in my GYTR tuner and no error codes come up. I reinstalled the OEM computer and won't start. Put GYTR computer back in. Won't start.

I lifted valve cover and checked timing marks which all line up. My spark is still very strong. I poured a small amount of gas into plug hole and still can't get it to fire at all.

Everything seems as it should be except for my compression reading of only 30 psi. 

 

I'm completely stumped and desperate for help. The thought of taking this to a mechanic is nauseating.

 

Can anyone tell me what psi is to be expected with throttle wide open and auto decompressor still operating? 



  • Krannie McKranface

Posted January 18, 2016 - 08:11 PM

#7

 

 

Can anyone tell me what psi is to be expected with throttle wide open and auto decompressor still operating? 

 

About 80 psi

 

Can't be something that complicated.



  • easystreet

Posted January 24, 2016 - 11:46 AM

#8

Update:

Purchased a HF cylinder leak down tester. Here is what I'm getting.

 

I am getting 50% to 70% leakage on any stroke at top dead center according to flywheel. The air is coming out the intake mostly, but some out exhaust as well. At no point during all rotations does it stop blowing air out the intake. The volume of air blowing out does change throughout cycling, but it's always leaking past intake valves. I believe it is always leaking past exhaust too just not as bad. 

 

I am at a loss how it could run fine when parked then couple months later have valves stuck open. Gonna sit back and scratch my head over this. Blows my mind to think a very gently ridden 2015 WR450f with maybe 15 hours could have bent valves or worn seats. 

 

Only other thought is could my decompression mechanism hold valves open rendering a leak down inaccurate?



  • morphrider

Posted January 24, 2016 - 12:22 PM

#9

This is a baffling result for sure.

  • 450crazy

Posted April 01, 2016 - 06:03 AM

#10

Were you able to get it running? What was the cause of the sticking valve?



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  • easystreet

Posted April 01, 2016 - 02:08 PM

#11

Were you able to get it running? What was the cause of the sticking valve?

Not running. I re-did the leak down a few times. It is only leaking past the intake valves at a pretty consistent 30% now. I pulled the fuel line and hit the button. Fuel pump is definitely working. I am wanting to make sure the injector isn't plugged, but after that it's off with the head. 

 

After fixed I am strongly leaning towards selling it. Just completely disappointed with Yamaha over this. 



  • easystreet

Posted April 01, 2016 - 02:11 PM

#12

Oh, and my valve clearances are all in spec so it's not a needed adjustment. 



  • 450crazy

Posted April 01, 2016 - 02:29 PM

#13

Man I'd take to the dealer on that one. I had a 2001 wr426 never did anything to it no valve adjustment nothing other than oil and plugs. Cleaned carb once. Got a 2015 wr450 last Oct and been riding it often no problems and love the power. I am betting the dealer will help though I haven't heard anyone else having this problem. Keep us posted on this if you can. Would love to know what the hell it is. Feel for ya on it too. Big investment to have problems like that.

Edited by 450crazy, April 01, 2016 - 02:30 PM.


  • Krannie McKranface

Posted April 01, 2016 - 03:05 PM

#14

It can be as simple as a piece of carbon stuck on an intake valve, preventing it from closing, but more likely you have an intake valve stuck in it's guide from rust.

 

You know you have a leak from the intake side, so you are going to have to remove the valve cover and inspect. You will be able to see a valve not closing based on comparing it's stem height to a valve that is closing. 

 

Assuming you did not bend a valve that was hanging, trying to start it....you should have not problem loosening the valve with some PB blaster overnight.

 

But more likly is that your timing chain skipped and you bent and intake valve if it is bent.



  • Chaconne

Posted April 01, 2016 - 04:22 PM

#15

Sounds suspicious are you the only one with access to the bike? Was it exactly like you left it 2 months ago?



  • morphrider

Posted April 02, 2016 - 06:26 PM

#16

He is only one with access to it. It sits in his shed next to other stuff. We are in a dry climate (Colorado) so I don't see how it could rust in a few months time. I would bring it back to the dealer even though warranty is out and bitch like hell buddy...

  • morphrider

Posted April 16, 2016 - 12:44 PM

#17

Update - I assume he will be hopping on at some point to verify this, but he did have a friend look at it and they swapped a fuse or two that did not appear to be blown and after a few attempts it fired up. It lives again! Big mystery though is why the fuse blew in the first place. It ran fine until parked. Now I know what will be going in his pack when we ride this summer, would suck to happen on a trail...

  • easystreet

Posted April 17, 2016 - 07:32 AM

#18

Yep as my friend above mentioned it is running now. I was about to pull the head off. A friend came by to run through theory. He pulled the 10 amp fuse near the battery out and said this thing was loose. I laughed because I knew he pulled the spare out. He then pulled the one in use. IT WAS NOT BLOWN. He said well lets swap them anyway. After about five minutes of power on/off and starter attempts it out of nowhere just fired up. It has started and ran fine since. I DO NOT believe the fuse was the culprit. Nor, does the guy who swapped it. He thinks the computer or a cam or crank sensor is defaulting. Another friend is thinking I have a grounding issue somewhere. 

Myself, I am still stumped and clueless. I was determined it was the loss of compression out the intake valves initially. Now I am thinking it's something electrical also. We wired in a horn at the headlight pod at beginning ownership. I am going to remove that system out of concerns. 

 

In closing, after a half year of one year of ownership I am so happy it's at least running again. I took it out on the street and it runs like a raped ape!



  • normanator27

Posted April 18, 2016 - 01:04 AM

#19

Yep as my friend above mentioned it is running now. I was about to pull the head off. A friend came by to run through theory. He pulled the 10 amp fuse near the battery out and said this thing was loose. I laughed because I knew he pulled the spare out. He then pulled the one in use. IT WAS NOT BLOWN. He said well lets swap them anyway. After about five minutes of power on/off and starter attempts it out of nowhere just fired up. It has started and ran fine since. I DO NOT believe the fuse was the culprit. Nor, does the guy who swapped it. He thinks the computer or a cam or crank sensor is defaulting. Another friend is thinking I have a grounding issue somewhere. 

Myself, I am still stumped and clueless. I was determined it was the loss of compression out the intake valves initially. Now I am thinking it's something electrical also. We wired in a horn at the headlight pod at beginning ownership. I am going to remove that system out of concerns. 

 

In closing, after a half year of one year of ownership I am so happy it's at least running again. I took it out on the street and it runs like a raped ape!

 

Thats good to hear. I had ongoing issues with my previous bike which I eventually ran out of patience with, before buying my wr. I hope you have trouble free iding from here. The yammies are supposed to be bulletproof. Mine certainly is.



  • 450crazy

Posted April 18, 2016 - 11:25 AM

#20

Good to hear you got her going. Have a blast with it!




 
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