G'day Mod BB and Sven I certainly agree with Mod BB about the confusion here.
This is the thing... All the evidence points to a 2.5 hp engine.
It makes perfect sense - given this is the larger 8 Series. The first 14" Model 45s were 6 Series. That's 6.65 cu compared with the larger 7.75 cu for the 8 Series. You can see the correlation between cu and design series.
The second factor is the carby system. The lower hp engines had vacujets, whereas the larger hp engines had pulsajets. The 450511 had the 8 series, but with basic vacujet, that relied on displaced volume to pull the fuel into the engine. The pulsajet had a diaphragm to assist fuel delivery.
The third factor is marketing. The 8 series could easily be detuned (for marketing purposes), and the 8 Series engines on Lawn Kings displayed as 2hp!
The gallery below shows the other two 450511 14" machines I have recorded. Both have 2.5 hp engines, both are type 0233-01. Also note the earlier mower number has an engine built in August, 1975.
This is why I have dated Sven's mower to the start of the new season, sometime after September 1, 1975. I believe it was a 2.5 engine.
The significance - for me - is that the 450511 was the last Model 45 14" made. It would disappear as Challenge Corp replaced it with the Morrison mowers of the late 1970s.
That's my best guess. ------------------------------------- Jack
