Ok i am a new Harley rider (v-twin noob) and i bought a 99 FXDX with some mods. The dealer couldnt tell me anything so maybe some of you can. I will post some pictures and see whats what.





located on bottom of heads no idea what the emblem is?




Whats this blue button?

 

blue buttons are compression releases and the stamp on the bottom of your CYLINDERS not your heads is most likely from the machinist who bored the cylinders. You may have something there............

 

thedonthere is correct.

 

Aside from the cowbell horn cover being tilted forward, it would seem to have high compression pistons installed. When you push down on the blue buttons, you should hear a click. You do this before you start the engine,each time, to make it easier on the starter motor.
I agree with the prior post about the machinist marks.

 

What ever you do dont push that blue button!

 

Just kidding they are manual compression releases and that is some Zippers Big Bore Cylinder Kit.

 

Wow guys thanks for the quick response. Now just need to figure out what size the previous owner took the Zippers cylinder and heads to.

Dyna Rider which chapter you with?

 

They are zippers cylinders with hi comp pistons more than likely

 

Most likely a 95 inch big bore kit with high compression pistons, bet it sounds real nice and throaty

 

The bike may have a 107" Zippers kit. They use compression releases in the 107".

http://zippersperformance.com/catalo...=862&prod=1556

If that's what you have, it's a real nice set up.