450 complete rebuild

4 replies to this topic
  • matt 153

Posted March 23, 2009 - 12:03 AM


I got this 06 450f of a guy i know from racing. hed taken in to the local bike shop and put it on the dyno, for some reason it was only putting out 42hp so they decided to try tune it through the carby to get back 8hp. it looks like it dropped a valve as you can see from the pics on of them is embeded in the cylinder head
so far parts list is as follows
5th gear locking dog (it blew up in 5th gear and snapped it)
gasket kit
piston, rings etc
valves, springs, seats
new cam bearing as some metal went into it
swing arm bearings and seals
stearing head bearing
front wheel bearings

we're trying to fix the cylinder head ourselves, its getting all the nicks and chips welded up now and then we'll machine it ourselves
its a great bike otherwise and it will fly when we get it going as it has oversized cams and a heavier flywheel already and we're prob doing some small upgrades as we fix it up so far we have stripped the engine completely down and washed everything in solvent and reoiled all bearings and gears etc. the cases are back together and now we r just waiting on parts

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Also im thinking of getting a new pipe for it. ive been thinking of a rocket carbon but havent decided yet. also any other mods you recommend doing while its apart

  • TD-3

Posted March 23, 2009 - 03:00 AM


I would take a good look at the crank assembly while it is apart. I would also take apart the oil pump and replace it if necessary.
Good luck :thumbsup:

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  • CaptainKnobby

Posted March 23, 2009 - 04:38 AM


I would take a good look at the crank assembly while it is apart. I would also take apart the oil pump and replace it if necessary.
Good luck :thumbsup:

He's right! If you are that deep into it you will be better off to make sure.

  • VB_Racing

Posted March 23, 2009 - 08:11 PM


Pay close attention to the valve seats in that head, they tend to come loose when the head gets beat up bad. You may be better off replacing the seats if you can find some cheaply. I had a seat fall out of a head a couple years ago and it wasn't pretty!!Good luck!!


  • matt 153

Posted March 23, 2009 - 09:42 PM


i forgot to mention we already changed out the rod as it looked a bit bent plus with the impact of pushing that valve into the head we didnt want to risk it, we r also replacing the cam chain incase it has a weak spot or any metal shavings in it. also pretty much all the valves and seats are ruined. we r ordering some soon but were waiting till we find out if we can fix the head first otherwise we'll order them in all together with a new head

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