ORIGINAL: mike109
G'day
Thanks everyone for the comments. I hope to see the engine and its owner tomorrow and I will pass on your comments.
My feeling is that the owner is now so happy with the way the engine is going that he will probably leave well enough alone though he may investigate the carby input problem.
The ultimate test for an engine is whether it flies the model it is in. In its original form it did not. It was un-reliable and difficult to handle and did not fly the model at all well.
With the larger prop and the Macs muffler it is a different engine and suits the model very well.
I will suggest we do some testing and see what happens when the carby is inspected and then suggest he try some smaller props.
Thanks again for the suggestions.
Mike from Oz
I'm not saying not to use the 12" +- prop if it is working well along with the Mac's Muffler. I'm just saying that its specialty is running at higher rpm, which probably isn't what the owner wants to do with it.
I've heard lots of stories about the carbs. Haven't heard of many fixes other than replacement. Sometimes one can find a Perry carb on eBay that is cheap enough not to tip the total price/value scale too hardily. I used to ask fellow club members if they had surplus carbs that they wanted to sell. Many times they would just give them to me. They don't have to be pretty to work right.
I have a NIB GMS .47 that I have been holding on to for a few years. I should pull it out and run it at least enough to break it in and go over it for air leaks.
Ed Cregger