the base engine is in fact a Honda lawnmower engine /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif
Take the plastic cowling off the top,
then remove the 3 nuts that hold the pull chord mech on.
Remove the fuel tank off the front and slowly work your way down ..
then flip it over and remove the 3 bolts that keep the leg on ....
keep removing bits until you find the impellor.
once you're down to just an engine block, put it all (except the impellor) in a box and post it to me so I can use it for spares!!
You can download a copy of the owners manual for FREE! HERE!
It has the maintainance shedule on p47 i think. (How helpful am I?!!! - thought I'd better check before posting!)
My old air-cooled 2hp model has an impeller in the leg, according to the Clymer service manual, but the owners book makes no mention of servicing it, so i assume it's a pretty low wear item compared to the impellers on water-cooled engines. (It does mention cleaning and relapping the cylinder every 300 hrs!)