Somehow we overlooked this unicorn when we compiled the recent 2024 Mecum Vegas Auction Preview. We think it was a late addition, because there is very little detail on this actual bike on the Mecum site (click Honda NS750 dirt tracker).
We know this is an example of the Honda USA factory racer that saw the Japanese manufacturer move into pro dirt track in the most serious way, having already won nationals with their 500 singles, notably the Astrodome TT with Mickey Fay.
Famously, the NS750 is powered by an engine based on the CX500 V-Twin. If you're not aware of that engine, it's an across-the-frame, shaft-drive V-twin, the engine configuration most associated with Moto Guzzi. Honda weren't making an inline-V-twin at the time (an engine with the more typical Harley XR750-like V-Twin architecture). Instead, they had the US development team, headed by Jerry Griffiths, rotate the V-twin they were making 90-degrees, and converted it to chain drive. Sounds easy? It wasn't. It is one of the most audacious examples of out of the box thinking ever seen in motorcycle racing.
Simply changing the orientation of a heavy, cruiser/streetbike engine 90-degrees and putting it in a chromoly frame wasn't going to be enough. The engine was bored and stroked, adding 50% to its original cylinder capacity, and the heads were 'swapped' to reposition the intakes, carbs and filters to allow the rider's right leg fit somewhere near to where it wanted to be.
Despite Honda signing up the then #1, Mike Kidd to race the NS750, it only won a single national, the 1982 Louisville Half-Mile, and that was with Scott Pearson on board. The NS750 project did give Honda the confidence to build the all-conquering RS750D though, and they won four Grand National titles with that as a factory team with Ricky Graham (one) and Bubba Shobert (three), and another with Ricky Graham as a privateer.
*Corrected 26-1-24. It was stated Honda won three title on the bounce. They won four, then another with Graham.
We don't know of any replicas (although we know of one being built in the Netherlands). This one is stamped with NS engine numbers, is in a C&J frame, and carries Freddie Spencer's numbers, who did race NS750s. It's obviously been restored.
If you want to learn just about everything imaginable about this era of Honda's dirt track history you need to get hold of When Honda Went Dirt Track Racing, written by Gerald Foster and Motion Pro founder, Chris Carter. It's a massive book that goes into the most minute detail. It cost $225 at release. I believe the 1000 copies of it have sold out, but resellers might have it.
You can see the first chapter online for free here.
Thanks to Patrick for bringing the NS750 listing to our attention.