| Author | Message | ||
     Silas_clone |
Will XB heads work on my '99 M2? Is it worth the effort? | ||
| Firemanjim |
Xb heads do not have the carb mount/breather holes drilled and tapped so unless you can do this forget it. Also the bolt spacing on front head mount is a bit different and you need a different mount. But they do flow better than worked on thunderstorm heads. Late XL or Screaming eagle heads are what you need, still require front mount. | ||
| Phelan |
Yes and maybe. The heads are not a direct swap since yours is a Thunderstorm motor. XB heads have a different bolt pattern so you either have to get a new front mount or I've heard of people redrilling the stock one. XB heads are not cut for squish band so they will not work with your stock pistons. You can either have a shop like NRHS cut the 15* squish into the XB heads ($50/head IIRC) or you can swap the stock pistons for flat tops. I prefer the squish cut myself. The XB heads have a more efficient design via bathtub chambers, smaller better shaped ports, and IIRC a different style of valve. They also have larger fins for better cooling and beefier looks. | ||
| Phelan |
Jim's post wasn't there while I was writing. +1 on everything he said, since he's done it  . To elaborate, I would recommend converting to XB rockerboxes as well, since it's a more efficient breather system, has less gaskets to start leaking, and looks really cool. I think you still have to have the breather holes drilled/tapped though for the carb mount if you use XB heads though, so if you can find the sporty variants you are closer and better off. The S/E heads are the same heads but decked .0500 IIRC. | ||
| Outdoors |
Check out the NRHS website. Lot's of good information and pics there. Really depends on what you want and how much you are willing to spend. Someone can always suggest how you can gain a bit more power for another chunk of cash. Good headwork is always a good place to start if looking for better performance from these motors but it has to work with whatever other modifications you are doing as well. Keep us posted as I have a 2000 M2. | ||
| Texastechx1 |
2004+ XL1200 heads are the same as XB heads except they HAVE the breather holes drilled into the side for you carb/FI. I'm not sure about the front mount though on those heads... anyone? And from what I've read, just swapping the heads is worth +/- 5rwhp over the Thunderstorms... but I'm not possitive about that. (Message edited by TexasTechX1 on January 09, 2009) | ||
| Firebolt020283 |
The front mount is still different. You would have to get the front mount from NHRS or American Sport Bike which look like the same mount. I thought the SE heads were the same but the stock heads were a little different. |
