After buying my ARC  Strega, Steve Fitton let me borrow his Brodak K&B 61 ABC engine to use. I had originally had some imput with Mike Garmon on the production of this engine. Bill Wisniewski sent us a Gold Twist head 61 to convert to control line stunt . This was in the winter and Mike wanted to use Fox Super Fuel that way any fuel would work. The engine would not run very good it would just stop in some embarrassing places. The engine was running too cold. Talking to Bill we explained that the twist head was too cold and needed to make the fins smaller. Bill said that they still made the old K&B 61 He put the abc liners in the old case . That was the cure the engine ran great The only change we made was a .312 venturi, that size was the best of all the ones we tried. Brodak ordered I think 300 of these ABC 61 Then K&B promptly went out of business.
 I put  Steve’s K&B in my Strega and It ran just like I remembered great ! With a 13 x 5 Zinger and a 6 oz tank at 9,000 rpm at sea level it ran only 6 min. I had to go too 6 1/2 oz tank. the engine is great in a Strega.
 Then at our local hobby shop I found a K&B 61 ABC twist head for 99 dollars retail. and also that the engine was still being manufactured. some say you can get it in a control line version. I bought the RC version and made a venturi and  had a light muffler laying around that fit, the K&B muffler weighs 3.9 oz. Found a OS SF 40 needle valve that fit.  The venturi base is about 3/4 inch wide.  I figured with some 50 50 fuel the engine would not cool off as much as 29 % castor in Fox fuel.
I flew the gold head 61  today and it ran as good as the Brodak K&B 61. For 99 dollars you can’t beat it. The 50 50 fuel worked like a champ.

Willis 

Crist,

I think Russ Gifford used a 'gold head' variant prior to running a PA61.  As I recall, Russ liked the run characteristics.

Fred

Willis,
Thanks.  That's why I asked because Russ spoke highly of them.

I have a few more flights on the K&B now The tank needs to be on the barriers with the engine and it can do the pattern with 6 oz of fuel. using 10 22 50-50 Power master fuel 13x5 Zinger  at  9,000 RPM turns 5.4 sec. on 68 ft lines on the rich side in level flight. The electric starter can now turn the engine over, before the first run it could not turn the engine. and don’t hardly prime it before starting it doesn’t take much.
Willis 

I hate to say this but the Strega weighs 74 oz. 

I checked Mecoa's web site and under Promo's they have this engine for 99.99 + S&H. I also checked and that page was last updated 3/07 so it's current. It is the R/C version. It's under Modeler Dirrect.

For this engine then the venturi of choice is the 312 ? and the OS SF 40 NVA ?

The Twist head (Gold) K&B 61 is the one I believe they are refering to.

Sorry I haven't checked this post lately. The ABC K&B 61 both the twist head and the Brodak stock style ABC 61 both have the two four style of run. I have no experience with the stock style 61 with a ring that they still make.
The Brodak style 61 you can't buy anymore.
Willis

Proparc
A few years ago I held Al Reed’s Patternmaster with a Greenway ST 60. I have never held any plane that pulled that hard on the ground. I remember thinking this plane is going to fly at 100 mph, There will be no way that he will be able to stunt this plane. Boy was I wrong, after that flight I knew what was ment by “stunt run”. If the plane was anything but the Patternmasater I would have bin right about the speed.
Willis 

Leester

The needle from the FS 40 is almost the same as a ST I think .153  It was a close fit as as I remember I didn’t even drill out the threads in the engine. The SF 46 is another animal it is a lot smaller .140 .  The K&B is .159, ST is .156
Willis