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
O.S. FT-120 flat twin engine
Jan 26, 2008
4 Replies
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."
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
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Any idea where I can get a back housing cover plate that fits the back of the crankcase?
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might try contacting OS. Sometimes they will have a few parts remaining.
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