Ken..the Hog looks fantastic. I'm really hoping to get my Suzuki Intruder 1400 chopper out on the road next summer. I went from getting paid to ride a Harley at work plus riding my Intruder to having the bike parked. Oh well, kids come 1st. I don't know what to suggest for the pipes..probably something petroleum based like Flash's suggestion...either gas or varsol or something with a bit of bite..maybe even diesel. I'd do 0000 steel wool doused in diesel and give er a try. Your shots are amazing. I gotta save up for a new camera. You just don't get great depth of field shots like you did in this one with an automatic camera. Great shots; great work. I love this shot...the depth of field is incredible!
Actually, all these shots are with the camera on Auto. LOL. The difference is the $800 lens. This is going to get real expensive, real fast. I already found my next lens. Another $800.
For the tar on the pipes try 0000 steel wool with 3M tar remover then Autosol . It worked for me afew weeks ago on my neighbours bike.