I have only bought the engines from TEW- or Staton Inc. and just payed the asking price- never seen one for a discount anywhere. Never seen one in a junk heap either. Never even seen one on a trimmer. People in South GA just don't spring for high dollar "brushcutters"- but used Ryobis' can be had by the barrel full.

Weird things happen on these Hondas when you try to use anything but the stock carb- I have tried several different butterfly carbs
and not had satisfactory results. Most folks that have good luck with the butterfly carbs are turning the carb into an external pulse and then tapping or "teeing" into the crankcase pressure transfer hose on the engine. The stock carb on the 35 is a pretty decent carb for it in stock form. You can play with the "pop-off" on the main metering system and richen it up a bit and it will help performance some- but you better know what you are doing when you do that- or you'll be ponying up about $80 for another stock carb (special order) just to get it run again. I kid you not- these things aren't like a two stroke where any old carb that looks "about the right size" will work well.

Right now I have a 12.2mm rotary valve walbro on my 35- it is the one with the adjustable low and high metering system- I have been able to make it work pretty well. You have to port the devil out of the plastic intake piece and the aluminum intake passage to be able to have it do any good when you increase the carb size though. I use them in an RC boat I have- and I have tried to get maximum horsepower at a higher RPM-
rather than torque, which is what a plane needs.