K&B .61: Changing bearings
I simply find a couple of thin chisels and gently tap them between the bearing and the crank journal one on each side. Ninety percent of the time the bearing will slide off without any heat. There is nothing behind the bearing that you can damage very easily this way so don't worry.
OR
On difficult ones I have made up a couple of thin steel plates with notches in them. I open my vice and lay the plates across the vice opening supporting the crank while they are wedged between the bearing and the crank journal one on either side with the threaded end of the crank poking up. Re-install the prop nut and thread it on 'till it's flush with the end of the crank. Grab a chunk of hard wood and place it on the prop nut and whack it with a hammer. If this does not work try it again but heat the bearing with a propane torch first.
I have never had to resort to using a press on this engine.
A note on using heat to remove bearings: The idea is to heat the bearing BEFORE the crank as you want the bearing to expand before the crank does. This is easier than it sounds because the crank has considerably more mass than the bearing and it takes longer to heat a larger mass. Point your torch directly onto the bearing's inner race and rotate the crank while doing this. After about 30 - 45 seconds the bearing should be hot enough to practically fall off.
Re-assembly is a snap. Start the bearing and make sure it's not cocked. Set the crank so it's supported by a couple of pieces of wood and tap the bearing into place. I use a hard plastic hammer for this. If it seems to be stubborn apply heat just to the bearing, get it good and hot and it will fall on.
While these methods might not be what other fellows use they have worked for me on EVERY K&B .61 I have dis-assembled.
BTW: The K&B .61 in one of my all time favorite engines. I have 2 that I bought from the original designer of the .61s Clarence Lee. Both have the PDP mod and were hand fit by CL himself.
Until just recently you could purchase a new one of these engines modified and hand fit by CL directly from him
but apparently the supply of new engines has run dry. CL will modify your engine for under $30.00 and it is well worth the money. His contact info is always in the classified adds in RCM magazine.
The K&B .61 started life as the old Veco .61. Last year I was able to find #73 Veco .61 hand signed by Mr. lee
I use this engine in a Sig Somethin' Extra with an APC 12.25X3.75 prop. It is great for hovering.
Check the pictures I posted here on RC Universe. The Kyosho Super Stearman Bipe in the pictures is powered by a CL modified K&B .61 with a tuned pipe. It performs much better than with the MDS .48 I started with.
GSG