Fellows,
I have a NIB 6550 which was purchased 20 years ago, but never got around to using. Am now thinking it may be a good choice for my Goldberg Extreme 330 Profile. I know this is an old-tech, loop scavenged engine which will not wind up like the newer fire-breathing schunurle ported fx's etc, but for this application I am primarily interested in a dependabe, well mannered, light .61 which would swing a 12x4 to 13x4 APC or maybe Zinger. ( The actual weight of my engine is 15
oz. and 3.5 oz. for the muffler, which has no baffle )

I have tried to research this engine in these forums and there is scant info regarding this engine, or tach readings. The only thing I found was a user review of the the K&B R.C which is supposedly the same 6550, with a remote needle valve.

I know there are a number of "experienced" modelers out there who have a lot of respect for these older engines, and ask the following:

- How well does the Carb adjust and perform? ( It's the original metal metering box w/ the K/B
stamped on it).

- Spec's show H.P. of 1.3 @ 12,000. ( I know it's a lousy way to evaluate power, but it's the
only number available). Anyone have any tach readings with a 12 or 13x4 ? How would this
engine compare with say a Supertigre .51 or OS 50 sx?

- How is the fuel consumption rate compared to the above ST or OS? Was thinking it should be
less, due to lower rpm's. Are the loop scavenged engines considered more fuel efficient? Not
trying to save money, just flying weight.

Any and all comments welcome, Thanks in advance


Blue Skies, Green Lights