Keith Black Pistons

[txspringer]

I'm installing a set of +.020 Keith Black pistons in an 83 80ci. and was curious why the flywheels need to be rebalanced when going from stock pistons to the KB pistons? What problems would be encountered if the flywheels are not rebalanced for the KB pistons. I'm new to working on shovel heads and don't want to ask too many dumb questions..
Trying to do the best job I can since this is my first shovel build and get it right the first time. Thanks in advance!
           Paul
           83 FLHT

[Mule]

 The weight difference in the pistons from stock is the reason for the recommendation. With KB pistons there is a 33% chance the bottom oil control ring will come down into the oil return in the cylinders, this is due to variations in the location of the return holes.   There were three different vendors that supplied jugs to HD  and one of the vendors had the oil return locations a little high, which is no problem with stock pistons, but can be a problem with wider ring pack pistons. Kbs some like them ,some hate them...Good luck...Mule...

[billbuilds]

     Be sure to gap the top compression properly. This is another area where KB's differ from stock pistons. Don't use the stock gap as heat from combustion can cause it to close up and bad things will happen.

[MBSKEAM]

follow the set up for the piston ring gap...
if you have both piston the same weight,then the only thing that will change will be the ballance factor

weigh your old piton/rings and new set up are they close?

mbskeam

[txspringer]

Not sure what the stock pistons weigh- will try to weigh them in the next couple days (post office has scales that I may be able to use. The perks of small town livin). I'm pretty sure I will have to reroute the oil return in the cylinders.