Cylinder and valve questions

1 reply to this topic
  • finthat

Posted January 17, 2009 - 02:23 PM


I bought a 03 450 with a blown motor and as soon as I get my cases back from the shop I will be putting it all back together. The new parts list is long since the rod went out of this bike hard. It is getting a new hot rods crank rod and bearigs, new cp piston, trans gears, counter shaft ect thanks to ebay. It wasn't a pretty sight when I pulled it apart and I should have mabe parted the rest of the bike out but I am now into do or die mode or past the point of no return plus I need a bike and kinda like fixing stuff.

The jug was also damaged and I have a used one but do not know how many hours are on it. The hone is pretty worn and I will have it re-honed. How can you tell when the cylinder is worn out? Is there a measurements to look at? The old cylinder looks pretty good with alot of cross hatch visible too bad the rod did a number on it.

Also when the piston left the rod it made contact with the center intake valve. It does not appear to have hit too hard as it only removed carbon off of the piston and the valve. And looks like only the one valve made contact. I asume the center valve would be the lowest one and if it were hit hard enough and bent badly the other two would also show damage. I am going to have them checked for straightness but am a little worried about coatings. Are the valves coated with anything that is easily damaged? If they are straight will the be ok? Should I just change them? Everthing seems to move freely on the head and there doesn't appear to be any damage to anything.

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  • mkporn

Posted January 17, 2009 - 05:58 PM


Replace the one that got smacked. They are Ti valves and are hard faced, not coated if stock. If you dont replace it and it is slightly bent, you will be pulling it back down to replace it and if you run it for very long you will be doing a valve guide also... so $80 bucks now, or you chance it and have to pull it back down, $30 head gasket, $80 valve and a few hours more labor.....Your call.

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