Oops. you're right. The hole centers across the top and bottom of the plate should have been 52mm. The rest of the dimensions are correct. I edited the post to reflect the change. Thanks for catching it Geistware.

As to the break in, I haven't done that yet. We're in the middle of what is turning out to be the rainy season of the decade here in central California. If it isn't raining, the wind is blowing 45mph plus. I'm going to start with an MSC 26-10 as suggested by Gary at Brison. I already know the MSC props work very well, so I'm not concerned about the prop. I uaually end up running the same prop for performance as I do for break in. I break them in the same way they are going to be flown all the time.

As for mufflers, I have the ones produced for the Brison 6.4 by Bisson mufflers. It's the only set they make for this engine. If you haven't already got one, take a look at the Kangke/Revolution 5" Ultimate spinner. It's well made, light, and polishes up easy and well if you want a polished prop. Price wasn't bad for it's size either. They also supply the spinner nut and the long bolt if you remember to ask for it. There was no extra charge for the nut and bolt on the billing invoice when mine was shipped, so maybe we finally have someone doing it right.

Send me a PM and I'll send a pic of the installation for reference purposes.

Pat