TNRC51

SP-2s were a slight improvement over the SP-1.  The changes to the fuel injection along with the swingarm made the handling and fueling a bit better.  All of them in bone stock condition are a bit jumpy to ride at slow speeds.  They are also geared too high for most practical riding.  Most owners opt for a fuel manager and change the gear ratio.  Usually, one up in back and one down if front does very nicely to make it easier around town.  The 2006 models are the most "rare" if that matters.  By 06 Honda was using up the frames and parts they had on hand and there may have been as few a 400 examples.  I've never seen any vin numbers higher than that.  The '05 is also all black.  From 2002 on they are all identical from year to year except paint schemes.  That being said, for some reason the 04 Nicky versions are all much faster than the others...   😉

Here is a link to the version used by a lot of the RC-51 guys. Also here is a forum link to someone who has installed them...

http://www.rc51forums.com/forums/showthread.php?t=7997

http://www.ebay.com/itm/Two-New-Spal-5-5-Pusher-RC-51-Motorcycle-ATV-Axial-Motor-Fans-/191240676656?pt=Motorcycles_Parts_Accessories&hash=item2c86d52530

If you live in hot climate you should investigate SPAL fans. They come in many sizes in both rotations. Very common mod in RVT world to help with nut roasting. Most change to "pusher" version. These things move air. As for manual overrides, fighting heat early in traffic is a big help.