Wr 400 Blues


39 replies to this topic
  • stumac31

Posted March 30, 2008 - 02:53 PM

#1

hey ,i have a problem with my 2000 wr 400
when no1 son was riding it the other day the engine died ,when we tried to restart it the old kickstart would not move ,,aaaahhhh siezed,,but when put in gear and pushed backwords it was ok ,started then popped ,done it again.
does anybody have any idea? thanks STU.....:prof: :bonk: :confused:

  • matt4x4

Posted March 31, 2008 - 04:47 AM

#2

Ok, things are a little vague so we need more info....

I don't want to sound like a smart ass, but you stated you moved the bike BACKWARDS and it freed the piston, this is why I'm asking these next questions - moving it backwards reverses the normal rotation of the motor essentially uncompressing the compressed gas easier than trying to get past TDC in a forward motion.....

First off, let me ask you - how long have you had the bike? Do you know the proper starting procedure?
Many times, people think the kicker doesn't move, when in fact they're at TDC and there's just too much compression - thus the decompression lever.....
Are you using it?

A pop can be normal, depending on how much fuel is in the cylinder etc.

Oh, the other reason I'm asking all these beginner questions is that you only have one post which can but doesn't necessarily mean "newbie" to the bike...

And if it "seized" a second time, it may just have hit TDC again.....

Can you help us help you by letting us know how much you know about your bike....

  • face_plant

Posted March 31, 2008 - 09:06 AM

#3

if it gets "stuck" i pull in the decomp lever and light actuate the kicker and it flops past tdc

the pop is normal, if mine stops poipping thats when i got a problem

o just in case NO THROTLE at all to start it

  • stumac31

Posted March 31, 2008 - 01:46 PM

#4

gday ive had the bike two years, its my second wr 400 ive got the starting down to a t this just happened, i romoved the spark plug and i could still not move kickstart downwordsbut after ipushed it backwords in second gear i was able to kick it freally then i put the plug in started it and it ran for 5 mins then stopped again the same again sound very puzzleing to me i think
thanks stu

  • stumac31

Posted March 31, 2008 - 02:24 PM

#5

oh, i forgot , i took the valve cover of and checked the cam chain all ok i think, anything below that is beyond my mechanical skills,i did think it could be some kind of valve problem,the bike has only been ridden 15 hours since i bought it(busted knee for 8 monthes) the valves were done then ,the oil is changed every three rides air cleaner every ride
thanks stu....

  • matt4x4

Posted April 01, 2008 - 06:02 AM

#6

The only thing I can recommend at this point is to try a brand new plug - the bike just stopping seems a little weird, but it might be plug related. As for the lockup at TDC, hmmm, possibly a bad top end rod bearing?

  • stumac31

Posted April 02, 2008 - 12:50 AM

#7

ill put a new plug in tomorrow then i think maybe the bike shop thanks for your help ill let u know how things go ,,stu

  • stumac31

Posted April 15, 2008 - 02:55 PM

#8

spoke to the bike shop today seems like big end bearing gone ,i did actualy talk with a guy at work ,same thing happened to him with his husky 610 ,he ended up wrecking it to much bucks to fix it.stu.....

  • Math

Posted April 15, 2008 - 05:20 PM

#9

spoke to the bike shop today seems like big end bearing gone ,i did actualy talk with a guy at work ,same thing happened to him with his husky 610 ,he ended up wrecking it to much bucks to fix it.stu.....


:thumbsup: Woh woh... dude! Let's try to stay calm..... We don't even know if the valves are still in the specs and you are posting about wrecking the whole bike!:thumbsup:

First, the bike is not that complicated that you can't have a look under step by step... If you have some time, a couple of tools and a digital camera, we can help you (some fellow here can help more than I can)...

If I were at your place, I would not try to start the bike again as if there is some kind of piece that's not doing it's job or that is partly uninstalled or broken, you can cause more damage to the head, the cylinder, piston, etc.

OK first, what were you doing with the bike when it happened? Did you hear any weird sound seconds before it died the last time?
What did you hear? Can you locate where it came from?

Others and myself will surely have more questions for you but let's start with this. By the way, the crankshaft bearing is supposed to produce a characteristic sound before it "suddenly explodes" so let's just not be too fast on conclusions... just my 2¢

  • Birdy426

Posted April 15, 2008 - 07:41 PM

#10

Could be the big end bearing...but it could also be a broken gear...either in-the tranny, or maybe the kick start idler...or maybe the primary drive gear, or maybe...well, you get the idea. At least drain the oil and look for bits of metal poop in it. Pull off the magneto (L/H) cover and look for bits of bearing stuck to the flywheel...not there? Probably not the big end bearing...pull off the clutch side cover (the R?H side, pull off the whole thing, not just the small cover) and see what you see. Then, assess (or post, with pictures) what you find and decide what to do...

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  • stumac31

Posted April 16, 2008 - 03:04 AM

#11

dumped the oil today and i found some metal shavings on the drain plug a little more than normal ,i checked the cams at tdc the little punch marks do not line up ,i dont know if this is due to yz timing, the inlet mark is slightly below the top of the head ,i did mention to the missus i was was going to tear it down my self but i guess she knows how bad a mechanic i am, do not touch it she said .when it started and ran for 5 minutes all the gears seamed ok,then she seized again,after pulling it backwards in gear the piston moves ok again thank stu ,,,,,

  • stumac31

Posted April 16, 2008 - 03:12 AM

#12

oh yes the bike was a little noisy compared to my last wr 400 ,also 2000 model it sounded to me like mabee the timing chain or in that area but more at idle when warm but its done that for two years since ive had it .my son reckoned it never made any strange noise when it siezed on him thanks for your help ,,,stu

  • Math

Posted April 16, 2008 - 05:30 AM

#13

oh yes the bike was a little noisy compared to my last wr 400 ,also 2000 model it sounded to me like mabee the timing chain or in that area but more at idle when warm but its done that for two years since ive had it .my son reckoned it never made any strange noise when it siezed on him thanks for your help ,,,stu


Let,s keep going

Ok, so then drain your oil and filter the oil to make sure you don't miss any big chunk.

Then I'd remove the pipe and header carefully and verify if there is any metal chunk in there. Shake it a bit and see if there is anything that falls out. It just happened to me that some type of metal piece found its way in the combustion chamber of my 426 and some metal chunks made their way in the header...found two in the header and two on the piston...:thumbsup:

Anyway... then you can follow the advises of Birdy426: if you still find nothing after looking in the oil and header, remove the magneto cover (which you already did to check valve timing at TDC) and seek for any metal chunk...) Use a magnet stick to reach places you can't see.

Then do the same on the clutch cover: remover the circular clutch cover and then the case piece that is just behind (you just have to remove the water pump (drain the coolant, disconnect the bottom coolant tube before), remove the oil filter and a couple of bolts... nothing tough to reassemble...just bolt-on parts) Try to find metal chunks again. Take the opportunity to check the kickstarter assembly while you are there. Use the magnet again to reach places you can't see in. Re-install if you find nothing. Be carefull not to damage the gaskets.

Let us know what you find and if there is nothing there, we'll try to guide you from the engine head down starting with timing and valve clearance. At anytime you can still chose to bring the bike to your favorite mechanic guru. So don't be afraid to give it a try. One of my best trick not to get lost is to put back the bolts where they belong while the part is unmounted...

Again... these are just my humble suggestions

  • pcmech2

Posted April 16, 2008 - 09:04 AM

#14

i just wanted to say as a newbie here, all you guys are fantastic. Quote: we will help you here" what a FANTASTIC place to be. I am honored to be a part of it.

  • wartsnuff

Posted April 16, 2008 - 09:49 AM

#15

^ ditto, been following this thread closly. waiting for the guys to reply...

cheers and thanks guys at TT :thumbsup:

  • stumac31

Posted April 16, 2008 - 02:04 PM

#16

hey guys am going to try what math said today, i will let u know how things go. has anybody got any ideas on why the timing marks do not line up with the top of the head? tdc lines up on fly

  • stumac31

Posted April 16, 2008 - 03:02 PM

#17

im not sure if this is a dumb question but should there be oil in the flywheel side casing , i know on my kdx two banger theres not. stu,,,,

  • Birdy426

Posted April 16, 2008 - 11:13 PM

#18

im not sure if this is a dumb question but should there be oil in the flywheel side casing , i know on my kdx two banger theres not. stu,,,,


Yup, there should be...no bottom end compression on a thumper, so no bottom end seals. Perfectly normal.

  • Math

Posted April 17, 2008 - 05:06 AM

#19

hey guys am going to try what math said today, i will let u know how things go. has anybody got any ideas on why the timing marks do not line up with the top of the head? tdc lines up on fly


I'll post pictures of my YZ timing tonight. This will surely help. Try to post pictures of your cams set up so we can have a look at it.

Birdy, thanks for helping.:thumbsup:

  • Frostbite

Posted April 17, 2008 - 06:14 AM

#20

My 400 locked up while trying to kick start. It was a long time ago, but something in the kickstart assembly itself broke, like the tab that holds the return spring in place, and resulted in a broken gear in the assembly. A piece of the gear jammed in the clutch drive gear, effectively locking up the engine, and it wouldn't kick over.

At the time i didn't know what had happened. Rotating the engine backwards freed it up so I knew it wasn't seized, but rotating it in either direction would eventually cause it to lock up. It would lock up in various spots, not consistant, so I knew it wasn't valve timing related. If the piston was hitting a valve it should lock up near the same spot every time. It was chunks of broken gear jamming up other gears on the clutch side. The pieces were sticking to the gears because of the oil, not falling to the bottom of the engine as you may expect. They would randomly lock up the engine. Pop off the clutch side cover and have a look.

If your engine locked, but now will turn, I seriously doubt it’s a big end bearing. If it was locking up at random rotation of the flywheel, it’s most likely broken pieces of something getting caught in between gear teeth.




 
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