Topic: Cb400f top end rebuild - newbie question on piston clearance...

[takeitdk]

So I found a set of +0.75 pistons for my stock cb400f cylinders.  I phoned my machinist who said: "...great... so just so we're on the same page, what do you want the piston clearance to be?"... to which I answered with a long air of silence.  Love those moments when the Newbie shines through!

Can anyone help me out with this?  Saw a tuning spec document (per Kaz Yoshima) that says "Street use 0.03mm-0.04mm".  My manuals are at a friends house but I assume if I look through them I'll find a range.  Am I supposed to give an exact number to my machinist? If so, what?

Thanks.

[gsnorcal]

Here are the factory specs. I would assume you want the same clearances with the oversized piston as the stock piston. So, you can just adjust the numbers accordingly.

Not sure if this helps, but trying.

Dave

[takeitdk]

Thanks Dave.  Looks like this is one of those art/science things.  I'm in Texas and the bike is for street use... I'll tell the machinist that and see what he suggests.

[bryanj]

Basicaly if the are Honda or Art pistons he bores it 0.75mm over the standard size and the clearances will be correct