jay760

I always use dellorto pumper carbs, but have manifolds made for them

It's the dot on the others idea the needs to be level with the face that you should be looking at ,it's too easy to get it a tooth out...

447 starting on the serial number does not define which rods are in it, there were several European models which would have 533 rods in...

Depends on how steep the ramps are, if its a nice smooth cam probably be fine, if they are really aggressive like on the 250-40 then no...

https://www.xs650.com/threads/anybody-recognize-this-cam.38585/ Jack has posted some useful information on measuring cam height on here...

Can you post a picture of the profile of the cam, You need to take the width from the height then times it by something think its 2.6...

Does it have a date stamped on it? First numbers 250 look like mega cycle numbers, if its an old cam they have different end numbers...

Perhaps it was built to be supercharged or turboed, that would count for the low compression,

Sounds like someone has put together a load of bits, crankcase half's should have matching numbers and the head should as well,