Topic: new 2nd over sized pistons, just want to clarify clearance.

[setdog]

Hello All

I have a 1973 CB750 K3.  Ive chosen to rebore the cylinders to 2nd over, (.50).
i got a .50 over kit from cyclex.

The manual says the "minimum" clearance between piston and cylinder is
0.0004~0.0016 inches.  or 0.01~0.04 mm.

even at the risk of sounding silly, i want to make sure i understand this.

*  is the manual saying the piston to cylinder clearance MUST be between 0.0004~0.0016 inches or 0.01~0.04 mm? 

*  if so, I should tell the machinist the clearance must be no less than .0004 in or 0.01 mm.? 

*  and he should measure a piston then bore a cylinder and label so i can match each piston to the corresponding cylinder?

I want to be able to instruct the machinist correctly. 

Some posts have said (if i recall correctly) tell machinist to add .0001 in. and go for a tight clearance.  I don't know if this is good advice or not for my application
im just putting in new pistons not planning on racing, but i was having trouble installing piston rings on old cylinders, they kept falling out of the oil groove and
getting stuck between wall and piston, so i figured wth more aftermarket rings...or a just a new kit from cyclex, i chose the new kit.

(EDIT:)  found on another post, to tell machinist to bore clearance to .001 inch

[Nic]

Yes, 1 thou if they are cast pistons, 2 for forged, and don't let them talk you out of it and watch out for dick head places that reckon you don't know what you're doing. One thou for cast, 2 for forged. Some places will say yes and yet do them bigger coz they know better 
 Getting valve guides done is another small clearance gamble I have found.

[chewbacca5000]

I did a .5 overbore from z1enterprises when they had the kits.  It was great!  Choose .0015 and it worked out fine.  Took it easy during the initial break in.  Make sure the shop has experience in MC boring and not just autos.  Autos are bored at a much larger clearance than bikes.

[setdog]

Thanks for the replies.

Ill be sure to tell them .001 and no cheating lol.

[Don R]

Be sure to check the end gap on your rings, inserted into each cylinder.

[setdog]

So i dropped the jugs off at the machine shop today.

i feel like a nervous mother whose kid just left for camp for the first time