HPBCANADA.COM

Here is a short video of 850cc racing in Australia.
https://www.youtube.com/watch?v=irA0tvH6fl4

Sure doesn't sound like yamahas racing maybe the one at the back of the field is a Yamaha

No Yamaha's. All 75hp 847cc OMC's with various modifications such as porting and finger ports. Some use the 15:28 nitro gear case with 23 in cleavers or the 12:29 ratio with 25 in props. Speed varies dependant upon modifications, set up and driver. Motors are a combination of numerous OMC 3 cylinder parts as these guys like to play around with what they can find. All boats are identical being out of the same mold. This video was taken some ten years ago when there were quite a few around. Dropped off since then due to lack of interest and cost of an APBA licence but renewed interest has brought these boats out of the shed to race. Numbers may increase in the future but lack of short driveshaft's and the 15:28 gears may make it a bit difficult.

Stephen Medaris

Pffft...come now. In REAL 850cc racing you know what's up...