What engine did Honda put in the GB500? Is it the same engine that was in the Ascot, XL and XRs?
Pete Plassmann: Yes, pretty much. Duke Robillard: It’s a 500cc version of the XR single (The Ascot was before my time, so I dunno what’s in there). The guys at my Honda dealer say these engines are bullet-proof. From Cycle magazine (March 1989) BHP 33.36 @ 7000 (on dyno) Torque 26.34 @ 6000 (on dyno) 0-60 5.1 1/4 14.13 @ 89.7 Weight 390.5, wet front wheel 2.15 x 18 tyre 90/90-18 rear wheel 2.50 x 18 tyre 110/90-18 Phillip Gray: The GB is a sleeved down XL600 engine displacing 498cc.. This means that it has the same stroke as the XL600 i.e 75mm. Its also running 8.9:1 compression so kickstarts are easy. Here’s some stats for you on bores/strokes: Model bore stroke XR600 98mm 80mm (long stroke motor) GB500 92mm 75mm (short stroke engine) XL600 100mm 75mm (NZ, Australian model) XR650L (NX650) 100mm 82mm (longer stroke again) (NX650 also called Dominator) GB400 84mm 72mm (Japan model, imported in NZ, shares very few parts with the GB500, engine wise anyway) The engine has a gear driven bal
