'08 WR450 decompression question


12 replies to this topic
  • AKmud

Posted April 28, 2016 - 08:53 AM

#1

Occasionally my bike gets stuck on a compression stroke when I shut it off and then the E-start won't turn it over.  I have to whack on the kick start a few times to get it past the compression stroke and then it will work fine.  Is this normal? Even the kick starter is really hard to get over the compression stroke.  I'm wondering if my decomp is getting stuck in the recessed position.



  • stevethe

Posted April 28, 2016 - 08:55 AM

#2

Most of them do it. But try not to whack the Kickstarter as you may break something.

  • AKmud

Posted April 28, 2016 - 09:35 AM

#3

Most of them do it. But try not to whack the Kickstarter as you may break something.

 

Maybe "whack" wasn't the right word.  I just have to climb on the bike and kick it a bit to get it past the compression stroke.



  • GuyGraham

Posted April 28, 2016 - 09:57 AM

#4

Put bike in gear and rock backwards to move piston back down the bore. It will then turnover on the e-start

  • AKmud

Posted April 28, 2016 - 11:31 AM

#5

So this is a common problem? I was thinking about popping the valve cover to inspect the decomp system...



  • Krannie McKranface

Posted April 28, 2016 - 11:34 AM

#6

So this is a common problem? I was thinking about popping the valve cover to inspect the decomp system...

Yes. Every year since 2003.

I just put it in gear and bump it over.

That or a couple of estar stabs to roll it over past the 'hump'.

 

But, if you add a large ground wire from the battery directly to the starter (bypassing all other harnesses and bolts) and use a Li-ion battery of 12cca or higher, it happens very rarely.



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  • DrFeelGood

Posted April 28, 2016 - 11:52 AM

#7

HA!

 

Right after I bought my 08, I drove 2+ hours to a place I wanted to ride called Fox Valley.  Got there no problem, unloaded the WR, geared up and headed into the woods.  About 15 minutes into my exploration of a new-to-me riding area I had the same thing happen. :jawdrop:  It stalled on a hill and locked up.  No magic button response, kick starter wouldn't budge at first.  It was a new bike so I wasn't about to start "slamming" stuff. :naughty:  I figured I'd take it home and crack it open before I caused serious damage.

 

So, I pushed it almost a quarter mile, uphill, in the mud, back to my trailer.  When I was about to load it, I decided to hit the e-start one time just to see what would happen and it turned over (whew...no major damage I thought :thumbsup: ).... I didn't start it because I didn't want to damage it if there was a problem.

 

Got home, dejected from a failed ride, and logged into ThumperTalk and learned that it was just the vaporlock decomp problem. :facepalm:   It happens about twice a day now, but I just lean on the kick starter for about 10 seconds and it eventually passes the compression stroke.

 

No worries. :ride:



  • toten

Posted April 28, 2016 - 12:01 PM

#8

Yes. Every year since 2003.

I just put it in gear and bump it over.

That or a couple of estar stabs to roll it over past the 'hump'.

 

But, if you add a large ground wire from the battery directly to the starter (bypassing all other harnesses and bolts) and use a Li-ion battery of 12cca or higher, it happens very rarely.

Hmm, I guess I ought to do that even though I tend to kick my WR thanks to the potential parts breakage on 2003 WR450 estart. What size wire do you use?

 

I suspect you mean 12 AhEq rather than CCA. The Shorai LFX14L2 that I run is 210CCA, so I can't imagine any battery used would be as low as 12. I sure will say that I love lithium batteries though: they weigh a lot less, they crank hard, the self-discharge rate is negligible, etc.



  • Krannie McKranface

Posted April 28, 2016 - 12:14 PM

#9

Hmm, I guess I ought to do that even though I tend to kick my WR thanks to the potential parts breakage on 2003 WR450 estart. What size wire do you use?

 

I suspect you mean 12 AhEq rather than CCA. The Shorai LFX14L2 that I run is 210CCA, so I can't imagine any battery used would be as low as 12. I sure will say that I love lithium batteries though: they weigh a lot less, they crank hard, the self-discharge rate is negligible, etc.

 

Yes 200+ CCA and 12 Amp hours, my mistake



  • Krannie McKranface

Posted April 28, 2016 - 12:16 PM

#10

Hmm, I guess I ought to do that even though I tend to kick my WR thanks to the potential parts breakage on 2003 WR450 estart. What size wire do you use?

 

I suspect you mean 12 AhEq rather than CCA. The Shorai LFX14L2 that I run is 210CCA, so I can't imagine any battery used would be as low as 12. I sure will say that I love lithium batteries though: they weigh a lot less, they crank hard, the self-discharge rate is negligible, etc.

 

 

Oh, 00 gauge is fine.

stockxpertcom_id30568511_jpg_6bfbace24d7

 

:jawdrop:

 

 

I use 12/2 or 14/4 or equivilent twisted together



  • jamesm113

Posted April 28, 2016 - 01:22 PM

#11

Yes 200+ CCA and 12 Amp hours, my mistake

Does the WPS FeatherWeight fit this description?

 

I bought my 07 with a dead battery and just threw a new WPS in there.  It doesn't always start the bike, but usually it will start on first kick.  Maybe starts right up 80% of the time.  The other 20%, the starter cranks, but I worry I'll drain the battery so i just kick start it.


Edited by jamesm113, April 28, 2016 - 01:23 PM.


  • Krannie McKranface

Posted April 28, 2016 - 01:25 PM

#12

Does the WPS FeatherWeight fit this description?

 

I bought my 07 with a dead battery and just threw a new WPS in there.  It doesn't always start the bike, but usually it will start on first kick.  Maybe starts right up 80% of the time.  The other 20%, the starter cranks, but I worry I'll drain the battery so i just kick start it.

 

Kicking spins the motor slightly faster, but not longer.

 

Many variables in starting.

 

If you have not replaced the plug or the carb wear components since 2007, look there first.......



  • jamesm113

Posted April 28, 2016 - 01:30 PM

#13

Kicking spins the motor slightly faster, but not longer.

 

Many variables in starting.

 

If you have not replaced the plug or the carb wear components since 2007, look there first.......

 

OK.  It starts first kick both cold & hot.  Just had some trouble with "halfway" cold starts that you helped me with in a previous post.  Carb has been cleaned with new gaskets/o-rings, JD jet kit installed & new NGK plug.






 
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