Wr 400 Blues
Posted March 30, 2008 - 02:53 PM
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.....
Posted March 31, 2008 - 04:47 AM
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....
Posted March 31, 2008 - 09:06 AM
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
Posted March 31, 2008 - 01:46 PM
Posted March 31, 2008 - 02:24 PM
Posted April 01, 2008 - 06:02 AM
Posted April 02, 2008 - 12:50 AM
Posted April 15, 2008 - 02:55 PM
Posted April 15, 2008 - 05:20 PM
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.....
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!
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¢
Posted April 15, 2008 - 07:41 PM
Posted April 16, 2008 - 03:04 AM
Posted April 16, 2008 - 03:12 AM
Posted April 16, 2008 - 05:30 AM
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...
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
Posted April 16, 2008 - 09:04 AM
Posted April 16, 2008 - 09:49 AM
cheers and thanks guys at TT
Posted April 16, 2008 - 02:04 PM
Posted April 16, 2008 - 03:02 PM
Posted April 16, 2008 - 11:13 PM
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.
Posted April 17, 2008 - 05:06 AM
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.
Posted April 17, 2008 - 06:14 AM
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.