Well it seems to be worked out. The shop couldn't replicate the problem....until they put it on a trailer and bounced around the block over some bumps. From what they can work out bouncing around on the trailer is bouncing the float around in the carbie and filling the float chamber right up, then when the ignition is turned on the fuel solenoid opens and the excess fuel just dumps into the cylinder and floods it. They put a fuel tap in the line and it seems the problem is solved.......we'll see next week. It does make sense although I've done some pretty rough travel over the years and never come across something like this.
I then pointed out to the dealer that although the manufacturer/importer (most likely the importer) won't cover things in the fuel system as they have no control over fuel quality, this is a simple design flaw. He gave me a choice of paying for the solenoid ($263) or paying 3 hours labour to troubleshoot the problem and fit the fuel tap ($285). I told him, even though I can understand his position I am going to take it up with Kohler in the US and the Australian distributor.....at which point he said to hold off on the bill for a while he takes it back to the importers. So currently we're at a stalemate. The mower shop guy also said difficulties dealing with the importers is one of the reasons Husqvana not longer use Kohler engines in Australia and why he no longer sells Ariens mowers......nice to know now. Incidentally the importer/distributor is a mob called EPG Engines.....anyone had anything to do with them?