So, I have looked all over the forum and I haven't found an exact answer to my query. I have a 2006 Sportster 1200 Roadster, with the 3 gallon peanut tank. I am looking to increase my fuel, for longer rides, so looking to get one of the 4.5 gallon tanks that come stock on the Custom. Will it work? I know that I will most likely have to modify my seat, or get a new one all together (which I was planning on doing anyways). Any help would be greatly appreciated! Has anyone done this, pictures? Thanks HD owners!

ps. I have a great lead on a tank, at an excellent price, so just trying to make sure before I make the long haul from Maine to VT to get this bad boy!

 

You'll be fine.
Your stock saddle will probably need trimmed because the 4.5 tank is longer. Remove the staples, pull back the seat cover, trim the foam with a serrated knife (sawing action) and re-staple the cover.
You might find a buyer for your stock saddle, rather than cut up a factory 1200R seat. I'd trade ya for this one:
https://www.hdforums.com/forum/sport...ther-2-up.html
The only issue you would have with a 4.5 tank is handlebar clearance. Looking at your sig pic, I'd say you're good to go.

 

That is exactly what I had planned on doing to the saddle, but I would totally trade for your saddle. However, I will say that I don't think it's a STOCK HD saddle though, I want to say its a La Pera (bike is still in storage, and my brain sucks at remembering stuff). As far as the bar clearance, I just put on 4 inch risers, so I think that would solve the problem, if there was going to be one with the old set up. PM me and we can discuss the sadddle trade! Also, thanks for the response, totally appreciate it.

 

If you want to trade, I have a 4.5 gallon tank on my 2005 Sportster custom. I am looking to get a smaller 3.3 gallon tank like yours.

 

Sent you a PM -- looking for a picture if you have it. Any dents, scratches, color? Hit me back, I would rather do a trade than buy one and then have to sell mine, ya know? It would be for the tank that is on my bike in my signature.

 

I will have to get you some closeups.