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katana head on a gs550e?

1394 Views 5 Replies 4 Participants Last post by  o1marc
hello everyone, new to this fourm and love it, friendly and healpful people and information
i purchased a 79 gs550e for 1,000 with 14,000 miles very fun, runs great would like to do more modfications this winter and one of tehe is performance ,
i have seen some disccution on this but most is just re jet stuff im looking for a little more, i have seen some talk of putting different heads and carbs on the 550 bottom end spifically th 650 katana, but knowng there are mny different years of katanas i was wondering if anyone recomends a specific year or model that bolt on , also are there other head/carb combo i could try? (looking for around 70-80 hp)
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Yeah, the 650 made 73 HP @ the CRANK. The 550 had 49 HP at the crank. (subtract about 20% for rear wheel HP) You are not going to get that much, just by swapping heads. There's a matter of an 18% increase in displacement. I am not sure what carbs would go with that kind of change, or if the 650 head would even fit. I do know that heads from a post 1980 550 won't work, because the carb spacing changed when they went to CV carbs...(which BTW are extremely difficult to tune without an air box). And I would assume you would need to modify or eliminate the air box with a carb change. And you would, at least need a rack to match the 650 head that you could install what ever carbs you went with.
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