Problem with my 450

[Shane102473]

Ok, went to start the 450 awhile back. Kicked over the bike and the kick starter stopped, wouldn't go down any. Long story short, empellor on water pump was torn up with a piece of metal in it. Don't know where the metal came from. Took clutch off and turned the crank, it turned and then stopped and wouldn't turn anymore. Turned crank backwards and it stopped again when the piston reached the same point. Thought to myself something was on top of piston keeping it from moving any further. Took off the head and turned the crank, this time the piston turned freely all the way through the cycle. I looked at the piston and the top was scratched. Anyone with any ideas? Valves appear to be fine. The torn up empellor has got me confused, where did the metal come from? Could the empellor problem be related to the crank problem?

[Anssi]

There's precious few places from where crap can get above the piston . Namely, your carburetor or your intake valves. Check if the aluminium plate on the cylinder side of your carb slide is still intact. Of course the cams could've jumped time but then the scratches would reveal this.

I fail to see how the water pump thing could have anything directly to do with the other thing.

[yzf450jack]

Is there somebody that don't want you to ride and put sh!+ in your bike so it won't run any more

[Shane102473]

Ok, got the top end back together today and the crank is turning like it is supposed to. I didn't do anything except take the head and the cylinder off to inspect everything, put it back together and it works.

Anyway, my next question may seem dumb but please answer it. On the head, right next to the exhaust, there is a hole in the head. It looks almost like the bolt on the back of the head where the oil delivery pipe goes, except for the fact that the hole doesn't appear to be threaded for a bolt. Please remember that I have not been able to work on my bike for a few weeks due to the fact that I have been moving, so I can't recall removing anything from this location. All the parts that came off is accounted for except for this. I have looked in the manually but am having a hard time finding where it talks about this.