RezoD
09-06-2006, 10:38 AM
Just wanted to give a big, first time Hello to all of you guys here, so, Hello! :blah:
A little background story... I bought this 2000 400ex a little over a month ago. It had a slight "knock" when I first bought it.. Thought nothing of it, because it's got a 416 kit and a full exhaust kit; Thought for sure the noise would be on any bike with those mods. Took it to Silver Lake, and found out I was blowin oil like crazy from where the cylinder meets the block... No big deal, simple gasket. Fast forward to about 2 weeks ago; Rode up to get the mail, and didn't use the clutch to shift into second coming back, and right after that it started knocking like CRAZY! Later found out that my timing tensioner's spring was broken, and it didn't keep the chain tight.. Skipped timing. I brought it back to the barn, and shut it down knowing something was up. Tore into the motor that night, and reset the timing (which was still off, I didn't do enough research and put the left line that is supposed to sit parallel with the head, straight up..) It was still running even with the timing being off this far, but it was still knocking (valves hitting the piston...). I thought it would do this from now on, so I took it for a quick 1 minute ride. Got it back in the barn, smoking pretty badly (unburnt fuel, not oil), and knocking worse than ever. So, I did what I always do.. Say eff it and revved the piss out of it. That killed it! :) Wouldn't start after that, and still won't even after I reset the timing (correctly this time) and bought a new timing tensioner. I couldn't figure out why it wouldn't start, and wondered if I blew a hole in my piston somehow. Tore into it this morning, and found THIS in my head!!
http://img.photobucket.com/albums/v332/RezoD/bentvalves.jpg
You can see that the left exhaust valve (right in the picture) is not seated fully. I have a feeler gauge, and was able to slip my largest feeler entirely under that gap, .6mm and I still had more. The right exhaust valve is bent too, but it seems not to that extent. Is this enough of a gap that it wouldn't let the engine fire? I have strong spark and plenty of fuel... This is my only guess.
http://img.photobucket.com/albums/v332/RezoD/SmackedPiston.jpg
The top of the piston (exhaust side), where the valves go into the engine.. You can see where they hit. They hit hard enough that they took it down to it's raw finish, not the black gunk on the rest of the piston.
http://img.photobucket.com/albums/v332/RezoD/bentvalves1.jpg
I'm sorry for the bad picture, but you can see the light shining through the valve, through the head.
So, what do I do guys? Do I send my head out and get oversize valves installed? I'd like that, because I will eventually be stepping up from this 416 to at least a 440, and I'd like to go to a 465 stroker. Or do I just try to find someone with a stock head and install that (eBay)?
Thanks guys, and sorry for the long post.. I've had 3 weeks of difficulties and no one to vent them to!!
Travis
A little background story... I bought this 2000 400ex a little over a month ago. It had a slight "knock" when I first bought it.. Thought nothing of it, because it's got a 416 kit and a full exhaust kit; Thought for sure the noise would be on any bike with those mods. Took it to Silver Lake, and found out I was blowin oil like crazy from where the cylinder meets the block... No big deal, simple gasket. Fast forward to about 2 weeks ago; Rode up to get the mail, and didn't use the clutch to shift into second coming back, and right after that it started knocking like CRAZY! Later found out that my timing tensioner's spring was broken, and it didn't keep the chain tight.. Skipped timing. I brought it back to the barn, and shut it down knowing something was up. Tore into the motor that night, and reset the timing (which was still off, I didn't do enough research and put the left line that is supposed to sit parallel with the head, straight up..) It was still running even with the timing being off this far, but it was still knocking (valves hitting the piston...). I thought it would do this from now on, so I took it for a quick 1 minute ride. Got it back in the barn, smoking pretty badly (unburnt fuel, not oil), and knocking worse than ever. So, I did what I always do.. Say eff it and revved the piss out of it. That killed it! :) Wouldn't start after that, and still won't even after I reset the timing (correctly this time) and bought a new timing tensioner. I couldn't figure out why it wouldn't start, and wondered if I blew a hole in my piston somehow. Tore into it this morning, and found THIS in my head!!
http://img.photobucket.com/albums/v332/RezoD/bentvalves.jpg
You can see that the left exhaust valve (right in the picture) is not seated fully. I have a feeler gauge, and was able to slip my largest feeler entirely under that gap, .6mm and I still had more. The right exhaust valve is bent too, but it seems not to that extent. Is this enough of a gap that it wouldn't let the engine fire? I have strong spark and plenty of fuel... This is my only guess.
http://img.photobucket.com/albums/v332/RezoD/SmackedPiston.jpg
The top of the piston (exhaust side), where the valves go into the engine.. You can see where they hit. They hit hard enough that they took it down to it's raw finish, not the black gunk on the rest of the piston.
http://img.photobucket.com/albums/v332/RezoD/bentvalves1.jpg
I'm sorry for the bad picture, but you can see the light shining through the valve, through the head.
So, what do I do guys? Do I send my head out and get oversize valves installed? I'd like that, because I will eventually be stepping up from this 416 to at least a 440, and I'd like to go to a 465 stroker. Or do I just try to find someone with a stock head and install that (eBay)?
Thanks guys, and sorry for the long post.. I've had 3 weeks of difficulties and no one to vent them to!!
Travis