WR426 starting/running problems.


4 replies to this topic
  • YUNOSTART?

Posted January 21, 2014 - 11:26 PM

#1

Hi Guys,

 

I have a 2002 WR426 that i bought about a year ago, in hindsight was probably a bad purchase as it has had a hard ife and a few dramas - but i bought it so now i'm stuck with it.

 

I had been away on holidays and hadn't ridden the bike for a couple of months. It was running fine before then however i did leave the fuel tap on during that time i was away (doh!)

 

Came back put fresh fuel in it and got it started eventually after flooding it the first time. After starting it i let it idle for a while and it seemed to be running fine, so i loaded it up and took it out for a ride.

 

I got it out and started it up rode about 2km then stopped to wait for a friend. The bike died and i thought it maybe it was because i stil had the cold start choke on. I got it started, turned the choke off and kept riding it was ok while the thottle was open but once i slowed down it would die, this happened two more times.

 

I suspected at this point something was not right, i went to start the bike again and although there was resistance in the kicker there was nothing happening with the decompression lever. It's like it just stopped working, very little resistance and no effect on the kicker.

 

I ended up having to push the bike back and am not sure where to start looking to fix it. The bike has had other dramas but this is the first time it's done this.

 

 

Something that i'm not sure is related: Occassionally when i kick the bike over it jumps into gear, the back wheel spins and then it dies, but it did this before.

 

 

 



  • flyandride

Posted January 22, 2014 - 11:55 AM

#2

Sounds like 2 problems.  Dirty or clogged pilot jet, that's why it won't idle or only will with the choke on.  

It may have a problem with the decompression mechanism.  If you pull the valve cover off it's obvious how it works.  Sounds like it may be sticking.   



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  • YUNOSTART?

Posted January 22, 2014 - 04:35 PM

#3

Sounds like 2 problems.  Dirty or clogged pilot jet, that's why it won't idle or only will with the choke on.  

It may have a problem with the decompression mechanism.  If you pull the valve cover off it's obvious how it works.  Sounds like it may be sticking.   

 

Thanks very much, I'll check those things out. i forgot to mention before that while it was running - it seemed to be lacking a bit of power, which i guess would also point to a dirty carb.


Edited by YUNOSTART?, January 22, 2014 - 04:36 PM.


  • YUNOSTART?

Posted February 17, 2014 - 05:04 PM

#4

Sounds like 2 problems.  Dirty or clogged pilot jet, that's why it won't idle or only will with the choke on.  

It may have a problem with the decompression mechanism.  If you pull the valve cover off it's obvious how it works.  Sounds like it may be sticking.   

 

I took the carb apart and cleaned it but it looked pretty good to be honest so i'm not sure if that was a problem or not. I've put it back on the bike and of course it's now got a leak from the top of the bowl (arghh!)

 

 

I pulled the valve cover off and had a look.

 

The decompression lever is working and i can see how it pushes down on the top of the valve but for some reason the cams were not in the right spot even though the kicker is at the top and wouldn't move, the exhaust valve that the decompression lever pushes on was down so the decompression mechanism was not contacting it.

 

I opened the plugs on the side of the case and used a socket wrench to turn the cams over so they were in the right spot, then put it back together and tried to kick it over.

 

It seemed ok and the decompression lever was working correcty again. I got the bike started after about 20 - 30 kicks, the bike ran for a few seconds then died. After that i noticed that the problem has re-occurred and the decompression lever no longer works again.

 

So i now know that its not a problem with the decompresion lever itself, not sure what to look at next.



  • flyandride

Posted February 17, 2014 - 06:13 PM

#5

I would check the valve clearances and then pull the cams.  Pull out the right exhaust valve bucket with a magnetic retrieval tool.  They all should come out easily, no binding allowed.  It sounds like a valve is sticking open.  






 
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