O.S. FT-120 flat twin engine

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

42 - 26 Jan 2008 18:31 GMT

To my understanding, OS made 2 versions of this engine. The Gemini and the
Gemini II, both now out of production. Can anyone explain the differences
between these two.
TIA

Reply to this Message

Lyman Slack - 26 Jan 2008 22:24 GMT

Seems to me the early version had a weak spot in the shaft/crankpin area????
I've only had the Gemini II, but it's still a sweet engine!
Cheers -- Lyman
"On so-called global warming or climate change, let us not scare ourselves
with catastrophic forecasts, or use them to defend and promote irrational
interventions in human lives."

> To my understanding, OS made 2 versions of this engine. The Gemini and the
> Gemini II, both now out of production. Can anyone explain the differences
> between these two.
> TIA

Reply to this Message

A.T. - 27 Jan 2008 09:29 GMT

Correct; the Gemini ll was a detuned 160 with big performance differences.
Hard to imagine any of the first FT-120 are still running as crankshafts
have been unavailable for past 5-6 years.
FWIW extract from my post to this n/group 03Aug99
OS Four stroke ratings =
FT-120 = .86kw or 1.2ps (difference between ps and hp is minute)
FT-120 11 = 1.32kw or 1.8ps ==significantly improved==
FT-160 = 1.47kw or 2.0ps
FT-240 = 2.87kw or 3.9ps
FS-120 111 = 2.1ps
FS-90 = .96 or 1.3ps
FS-91 = 1.6ps

Regards
Alan T.
Alan's Hobby Model & RC FAQ Web Links
http://homepages.ihug.co.nz/~atong

> Seems to me the early version had a weak spot in the shaft/crankpin
> area???? I've only had the Gemini II, but it's still a sweet engine!
[quoted text clipped - 7 lines]
>> differences between these two.
>> TIA

Reply to this Message

Model Forum / Radio Controlled / Air Models / January 2008

O.S. FT-120 flat twin engine