[Dantastic]

Hi guys,

Ive recently stripped the top end to replace the piston. The crank was at TDC when i started but as i took the sprocket off i managed to turn it a good couple of revolutions before undoung the 2 allen bolts.

My question is how do i get the timing sorted? When i put the cam back on and apply the sprocket i know theres the arrows but how do i ensure its on the right stroke and the timing will be correct?

Bikes an 04 450crf

Thanks

Dan

[staffy24]

i would start from scratch you can take both inspection plugs out one on the left one on the right they are hex key caps if the bike is up right you wont lose any oil line up the marks on both sides making sure the piston is at the top cam lobes facing to the rear then place the sprocket in the chain while making sure the mark on the sprocket line up with the mark on the cam holder if you look you will find pics and a how to on this site oh and i'm sure some one here will post the correct way lol

[Dantastic]

Cheers. Theres no oil in it anyway so not worried about that. I have had the cover off already to check the valves so if its a cas of getting the piston at the top and pointing the cam in the right direction I am ok. What do you do with the cam chain however while trying to get the piston at the right point? Ive read that if you move the crank while the chain is not in positiion it can damage the engine. Is this only if the crank gets wrapped up in it? At the minute its held tight by pliers or cable ties depending on what I doing at the time!

Dan

[staffy24]

its up to you you could have a friend hold the chain while you line up the crank just keep the tension on don't let it drop down. don't forget the piston needs to be on the firing stroke that is why you need to use the marks in the left and right side as well as the ones on the cam sprocket but if your bottom is lined up spot on and the cam is facing back place the sproket in the chain tight to the left it should line up?