'04 YZ450F - Motor Problem Issue ?

HELP !!!

I had, quite possibly, a "costly weekend" while out riding my 2004 YZ450F bike with my son, last Sunday. Two days prior to this, I just got done replacing my worn-out "clutch/friction plates" with a new Barnett Carbon Fiber Kit inc/springs and of course, replacing the oil with Yamaha's Yamalube for 4-strokes. Took it out for a test spin, and it shifted beautifully, without hesitation. Then came Sunday. I was out with my son riding for a little over an hour, or so, and then I had an overheating condition (radiator was smoking while I was trying to climb up a very rocky hillside). Once this happened, I decided to find an alternate route up to the crest. Then riding was fine for about another 30 minutes, or so. Then, on a straight away, in fourth gear, my bike just shutoff on me, like I had just hit the "kill switch" (which I hadn't, of course). Then when I came to a stop, I was able to kickstart it again, on the 1st kick. Then I proceeded on down towards the parking lot where my truck was parked, and I was in 3rd gear, and it started to stall on me, once again.....the only difference this time, it was making a "knocking noise" while my bike was still on and running. Then, at this point, I decided to shut it off and push it back to my truck. It was there, where my son had discovered that the "oil drain bolt" located on the frame, below the triple clamp, was missing. Needless-to-say, my oil level wasn't anywhere on the dipstick. The following day, I added some more Yamaha oil back to my bike, and while doing this, I also noticed my radiator fluid wasn't full, either. I couldn't see any coolant once the cap was removed. I then added some coolant to this, which took about a cup, or so, then it was full, once again. The bottom-line now is, I have both fluids at the right full-mark, or point, with regard to my oil and coolant levels, but the bike, when started, makes a unique "knocking noise" or the like. It also appears as though it smokes a little, down near where the bottom radiator hose goes into the engine on this bike. The question I have, now of course, what kinds of things could have been "possibly damaged" , or need examined from running low on both my oil and coolant levels ? Apparently, my oil drain-bolt wasn't secured, or tightened enough to prevent it from unthreading and falling off....UNBELIEVABLE, but true !

One "bummed-out" 4 Stroker enthusiast,

MXDKP - :thumbsup:

When your bike overheats it spits coolent out the overflow hose I wouldnt worry much about that as much as the oil leaking out ..how much oil did you have to add to bring it back up to normal? anything over a 1/2 qt and its time to split the cases :thumbsup:

He said the bolt was gone. If there was not also a fat stream of oil coming out of it at that moment, it is, as they say, too late. Time for a tear down.

unfortunately quite possibly a costly mishap.....Time to learn how to rebuild a motor...the top and bottom need to be checked

also check your oil to see if it is milky - this means water and oil are mixing....another bad sign

sorry but you need to yank the motor out and rebuild it.

time for a big bore kit??

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