K&B .61 owners,

I just bought a never been flown Carl Goldberg Super Chipmunk that was built 15 years ago with a never been run K&B .61 (6550 model) with a Tatone muffler. I went to my local hobby store and was recommended to use a 12x6 APC prop. Break in involved running on the rich side with 1 tank of 10% castor synth blend and 1 tank of 15% all synthetic. The APC 12x6 flight and wooden 11x7.5 flight were noticably different.

Thank you all for this thread and what it has done for my K&B .61. I was NOT a happy camper until I changed to the wood 11x7.5. I will surely be trying the master air screw brand as well as the APC in that 11x7.5 size if I can find them.

root