The A-75 gets its 75 HP by turning 2600. The Manual recommended cruise rpm
is 2350. I would check the timing as it is 29° for the top plugs (right
mag) and 32° for the bottom plugs. It is NOT timed the same as the A-65.
--
Cy Galley - Aeronca Aviators Club
Newsletter Editor & EAA TC
www.aeronca.org
Actively supporting Aeroncas every day

"Heino & Deanne Weisberg" wrote in message
...
I have a Stitts SA-3A playboy I picked up recently. It has an A-75
Continental and a 67" Fottorp prop with a 47 pitch. The plans indicate
this machine should fly around 120 mph with this engine; no mention of
prop. A previous owner I spoke to said it cruised around 118mph for him.
For me, it cruises around 95mph; I verified this with GPS. On run-up, I
get about 2250 max RPM. On take-off it easily red-lines, suggesting to me
the prop is not a good match, but then I know next to nothing about this.
It flies beautifully, feels very well rigged. I won't pretend I know what
the problem could be; but I do know it is flying a lot slower than it
should. Any suggestions would be greatly appreciated!!
Thank you
Heino