[jermkline]

Howdy all. New owner of my first 03 450r. Also undertaking a top end rebuild and refresh on the engine.

Down to the question... The seal in the left engine cover that mates with the crank for oil pressure, what side should the tension spring be on? This is the seal behind the stator, washing and c-clip.

Right now, the seal has the spring facing towards the crank. Logic tells me this is wrong due to oil pressure. Am wondering what y'all have to say. I'm thinking the seal (spring side) should face out, towards the side of the oil pressure.Otherwise, oil will blow past the seal and starve the rod.

So this bike had a 488cc kit installed and at some point pitched the piston in the cylinder. The destruction was pretty impressive. I've been gathering parts and getting it back together. The things we do for fun

I'll get a picture posted of the piston.

[JimDirt]

Welcome to the site !!

The seal should go in with the rubber side out , like normal (spring side in like yours was when you disassembled it)

[jermkline]

Hi JimDirt

Thanks for the reply and the welcome

The seal that I'm talking about is in the left cover. Here is a picture. I decided to install it with the rubber side towards the engine and the spring side out. Can't see behind the washer and c-clip but its back there.

Oh and here is the pic of the piston. Yeah baby!

http://crfsonly.com/forum/album_pic.php?pic_id=2514
http://crfsonly.com/forum/album_pic.php?pic_id=2516
http://crfsonly.com/forum/album_pic.php?pic_id=2515

EDIT> Hmm couldn't seem to get the imbedded image [img] code to work so went with [url]

[JimDirt]

My bad , i was thinking the Left Side Engine Case/Crank Seal which is why i posted that image from the Service Manual, , and its been a while since i had one apart to remember the orientation of the seal , but i would guess if it was in a certain way , i would replace it that same way unless you had top end oiling issues , and that piston looks sweet , i would have thought you could have got a few more rides out of it , looks like those little scuffs would buff right out , a new set of rings and you would be good to go

On the plus side , its a good conversation piece