i have a 400ex with a white bros comeplete exhaust and its jetted a little rich. Its starting to use some oil and if im going to have to take the motor apart i was thinking of movin up to a 416. Is there anything i need to do to the motor besides bore it? Do i need a new cam and does it need to be ported and polished?

 

anyone? some help

 

No, you shouldn't need to change anything other than a new piston and rings. All your other components should compliment the overbore. However, if you are still using the stock cam then I would strongly suggest a webb or stage 1 hotcam. Both are very popular. I have a white bros desert cam in mine that seems to work well in my white bros desert pack 440.

And as far as a port and polish job, that depends on how much money you want to throw at it. Every little bit helps but if you're going to have someone port it for you just remember that labor on that is pricey. I noticed a good midrange increase with my ported head but of course I did all my own work.