Hi,

I've recently bought my first ever brand new engine - an Irvine 53. I've got a World Models 46 P-51 Mustang and am not sure I'm getting the power i would expect.. ..let me explain...

The Mustang is a scale model and as such has the huge spinner to fit flush with the engine cowling - It's a large spinner.

I ran the Irvine in on a 12x6 prop - did it as the book says - rich etc etc..

But found that when I came to fly, the revs were'nt quite reaching that 'peak' you hear which tells you the engine is running at optimum, slightly rich.

I've come down in the sizes and have now reached down as far as a 11x6. What concerns me is that friends are telling me that from this engine I should easily be able to swing a 13x4/5!!

Also I'm getting (as ever..) mixed messages from experienced model shops regards the spinner size - some say you should place a smaller spinner on as this will give more prop area to 'bite' (but surely this would influence the revs not being as high..) - and would certainly not look as realistic. Whilst another shop tells me that this advice is wrong as it's only the ends of the propeller blades which produce the thrust.

Help!!??