Hi Garry, without knowing what surface you fly off but if you have limited take off and landing facilities beware of the weight you are carrying. I flew my flash today powered by a wren ss.I have a home made fuselage tank which carries 3.5.liters or there about and I only fuel it to 2 litres and always wait for a day with a good head wind and the grass is well mown. I also have a Simjet 3000 but at my age I wouldn't consider installing it in my flash. It is fast enough with the 18 pound wren, but thats a peresonal thing. I would also heed the advice on take off and landing flap deflection discussed earlier in the thread. It is a fabulous flyer and you will thouroughly enjoy flying it. Let us all know how you get on, Ron.