Jump to content

  • Follow us:

  • Facebook
  • YouTube
  • Twitter
  • Google+
  • Instagram
  • RSS Feed
  • Google+




Related Reviews

Yamaha YZ450F 2008


Last review by thaoe_thumper
* * * * -

Yamaha YZ450F 2006


Last review by Yzrider1023
* * * * -

Yamaha YZ450F 2014


Last review by Gode
* * * * -

Yamaha YZ450F 2009


Last review by w5rjh
* * * * -

Yamaha YZ450F 2004


Last review by 1trackmind
* * * * -



Related Garage

2004_Yamaha_YZ_450F.jpg

Yamaha YZ450F (2004)


Owner: 1trackmind
Added on November 29, 2016
Photo
- - - - -

14 YZ450F - non-starting issue, ignition system



30 replies to this topic
  • GHILL28

    TT Addict

3,832 posts
Location: California

Posted June 05, 2016 - 05:37 PM


60h on bike, I just finished cleaned the fuel injector and fuel filter before the last ride.  Re-installed both, bike started right up, hot starting seemed to improve.  Aside from that, and an install of a Baja Designs Squadron plug'n'play headlight, the ignition system hasn't been touched since I put in a different map when the bike was new.

 

Got out for an actual ride, bike died about a mile from the truck.  I look down to see the pipe has melted the power cable for the fuel pump (IMS tank, cable routing is funky).  I wrap it in electrical tape, secure it elsewhere, and move on.  

 

After a couple more stops and starts, the bike won't start.  I can smell gas, it has compression.  I re-seat all the connectors and it fires up, with some hesitation.  For the rest of the ride it seems to start OK.

 

Now, back at home, complete non-start.  Choke in/out, throttle open a little, closed, whatever.  Nothing.

 

 

I have to fly out early tomorrow morning for a work trip all week and I had planned a trip with the bike next weekend, which likely isn't going to happen unless I can identify the issue and fix it and test it Thursday evening when I get home.

 

So, with a limited time window, what are the items to check here?  Could the short from the pipe have damaged other components in the system?  For those who have gone through ignition system troubleshooting, is there a quick order of things to go through and qualify?

 

Thanks in advance.



  • GHILL28

    TT Addict

3,832 posts
Location: California

Posted June 05, 2016 - 09:57 PM


Will be able to check the fuel pump tomorrow morning before I take off with a 9V battery.

 

My main concern is with the wiring harness, having part of it melted against the pipe.  Could this be affecting the required power for the fuel pump on startup?  I know it takes a lot more power on start-up versus normal running, which explains why it was hard to start but ran fine.  How could I qualify that?



  • grayracer513
42,862 posts
Location: California
Garage View Garage

Posted June 06, 2016 - 07:00 AM


Any of the leads that were damaged coaxial or shielded conductors?



  • GHILL28

    TT Addict

3,832 posts
Location: California

Posted June 06, 2016 - 09:04 AM


The only thing that was physically damaged was the power cable for the fuel pump mid-cable. No other connectors showed any damage.

  • GHILL28

    TT Addict

3,832 posts
Location: California

Posted June 07, 2016 - 08:34 AM


I have a complete electrical system off a brand new '14 YZ450F that was being parted out on EBay on the way.  CDI/ECU, reg/rect, coil, condenser, wiring harness.  Only thing it's missing is the stator.  So the part swapping will commence as soon as I get back and I will sell off the rest.



  • GHILL28

    TT Addict

3,832 posts
Location: California

Posted June 13, 2016 - 08:50 PM


Upon disassembly, it looks like the wire that melted was the cable going to the condensor from the Baja Designs wiring harness for the headlight.  Can't quite visualize how a short in that spot would interact with the stock wiring, but whatever.

 

 

Tested fuel pump with a 9V, cycles audibly.  Injector passes fuel when the fuel pump is cycled.

 

No spark.  Plus is corroded badly around the hex, and "sooty" at the tip.

 

Replaced condensor, CDI, and coil.  No spark.  Next is qualify the stator.  Oh, and try a new spark plug.  

 

 

So, ways to qualify stator output?  Voltmeter to the connector?



  • grayracer513
42,862 posts
Location: California
Garage View Garage

Posted June 14, 2016 - 07:04 AM


Testing for spark with a sooted plug?  Could be fooling yourself. 

 

If the wire that melted was simply carrying more current than its gauge size could support, that's one thing, but if it was shorted, and was tied to the power side rather than after the load, it would have pulled down the voltage of the entire system.



  • GHILL28

    TT Addict

3,832 posts
Location: California

Posted June 14, 2016 - 07:19 AM


Yep, well aware the sooted plug is likely the problem. I had a fast system for swapping thru components and a bit of time after the auto parts stores had closed.

What causes a 4T plug to foul anyway?

  • grayracer513
42,862 posts
Location: California
Garage View Garage

Posted June 14, 2016 - 08:47 AM


5 things, usually, and a possible 6th. 

 

  1. Oil fouling
  2. Rich mixture
  3. Weak spark
  4. heat range too cold (see 5)
  5. Failure of the spark plug to reach operating temperature and remain at that temp for at least 5-10 minutes (most common cause)

#1 is obvious, but not common.  2 & 3 form a conductive soot deposit.  #5 is the most common culprit. The 6th is unusual: When the engine operates for most of its time under extremes of high power output, mostly full throttle extended acceleration, and such, a conductive glaze can develop that will produce a misfire under heavy loads due to shorting the spark.



  • GHILL28

    TT Addict

3,832 posts
Location: California

Posted June 14, 2016 - 09:06 AM


Running MXA map. Can smell gas from the exhaust under normal operation. Plug is dry and sooty (doesn't look like a fouled plug from a 2T). Bike has plenty of comp and power so I don't suspect rings.

  • grayracer513
42,862 posts
Location: California
Garage View Garage

Posted June 14, 2016 - 09:09 AM


So, after a day's ride, it still looks dry, black, and sooty?  Not mid brown and clean?

 

Probably need to back off the fuel at least in the lower cell ranges.



  • GHILL28

    TT Addict

3,832 posts
Location: California

Posted June 14, 2016 - 09:13 AM


No idea. 60h on bike and only removed it for the first time last night. IMS tank makes frequent access somewhat prohibitive.

  • GHILL28

    TT Addict

3,832 posts
Location: California

Posted June 14, 2016 - 06:05 PM


Tried new spark plug, nothing.  Going to find a multi-meter and start qualifying the various parts of the system until something shows up weird.



  • mxrider4life847

    TT Member

92 posts
Location: Texas
Garage View Garage

Posted June 19, 2016 - 08:11 PM


Maybe something screwy with the kill switch?

  • GHILL28

    TT Addict

3,832 posts
Location: California

Posted June 20, 2016 - 01:23 PM


I've had kill switches do weird things like that before on 2T's.  How do you even qualify a kill switch?  Just put on a new one, or is there a continuity spec?



  • mxrider4life847

    TT Member

92 posts
Location: Texas
Garage View Garage

Posted June 20, 2016 - 03:39 PM


Yeah, there are a few things you can do... I'm not 100% sure about the injected 450F, but follow the kill switch lead down to the connector, disconnect it and kick the bike over. If there is spark, you found the problem. Otherwise, will have to dig deeper. I don't have the wiring prints for a 14 yz450, or id give you some more checks.

  • grayracer513
42,862 posts
Location: California
Garage View Garage

Posted June 21, 2016 - 06:49 AM


How do you even qualify a kill switch?

They're easy. Connect a VOM to both leads.  It's supposed to be open when not pressed, closed when pressed.  If it passes that test, hold the meter in your hand while you wiggle, jiggle, and bang on the bars.  Should see nothing but an open circuit unless you push the button.



  • GHILL28

    TT Addict

3,832 posts
Location: California

Posted June 24, 2016 - 05:32 PM


Killswitch checks out.

 

I've replaced the stator/pickup, reg/rect, condensor, ECU, coil, spark plug, and wiring harness.  Still no spark.

 

Any other ideas?  Not having a second set of hands makes it tough to check voltage of the stator when kicking.

 

Entertaining the idea of just parting it out and getting a new bike at this point.  No local shops know a damn thing about diagnosing EFI bikes, and I'd probably end up with a $500-1k bill for someone else to learn on my stuff.



  • GHILL28

    TT Addict

3,832 posts
Location: California

Posted June 25, 2016 - 01:19 PM


What voltage should the stator put out when kicking?  The manual is kind of useless for checking anything besides resistance on all of these.



  • GHILL28

    TT Addict

3,832 posts
Location: California

Posted June 25, 2016 - 03:01 PM


Well, the fuel pump and condensor are getting DC voltage when kicking.  Can't really tell how much because I only have two hands.

 

The spark plug boot is also getting voltage (where it contacts the spark plug).  But still no spark, and using a few brand new plugs.

 

Seriously, F this manual for not giving any voltage specs on this.  All ohm readings are in spec, but nothing about required power at startup.







Related Content

Forums
Photo

2016 YZ450 by CaptainKnobby


Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies
Forums
Photo
Motocross

Thinking about Yamaha 250... by Arctic Pride


Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  491 replies
Forums
Photo

Chubby dad, looking at bikes , First trip to the orange/black forum ! by Slow_ride


Dirt Bike   Make / Model Specific   KTM   250-530 EXC/MXC/SXC/XC-W/XCR-W (4-Strokes)
  • Hot  28 replies
Forums
Photo

James Stewart back on a YZ450F by YamaLink


Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  47 replies
Forums
Photo

Is it worth it? (Cam and High compression piston) by macgi77


Dirt Bike   Make / Model Specific   Honda   CRF 150/230 F/L
  • Hot  36 replies

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users

 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.