Does anyone know the difference between the p500 engine and the new one in the p520 besides a few more cc's ?
Hi,
The only thing that I ever found through reading articles was an increase to the bore. The stroke, compression and throttle body are the same from the P500 to the P520.
Still, 43cc's from the increase in bore is a nice bump. Not quite 10%, but they didn't add that much weight either.
Rob
@906UP rebuilt his 500 to a 520 cc. He might be able to shed some light.
The difference is a 2mm larger bore, as
@crewcabrob everything else is the same. I checked the part numbers for the TB, injector, even the ECU is the same, so I assume the fuel map is the same.
Honda claims a 1.2hp increase (or something like that), they didn't give torque numbers but it feels like it has a bit more low end grunt. It seems to pull hills a bit better and holds top end runs a bit better. I found a couple articles about it from when they introduced it in the Foretrax line up and they made it sound like it had more to do with emissions improvements than anything.
I rebuilt the top end on mine this past winter, it's not a simple bolt on by any means. I ended splitting the cases and completely gutting the bottom end & trans, bolting the cases back together and machining the bore in the case to fit the 518cc cyl. Mine was ready for a top end anyways so it was a bit more work but I had time. I ordered all OEM parts from Honda..... cylinder, piston, rings & gaskets.