Seca 900 Carb Type

Wondering if the 83 Seca 900 came with a couple variations of the 35mm mikuni carb. Both my and my brothers 900 have the same looking 35mm mikuni carb. Just got another one and the carb is configured a little different. It's still a 35mm mikuni and lines up with the engine intake boots fine but the idle adjustment is straight down as opposed to sort of horizontal on the other two and it has two intakes for the fuel. Also looks a little different when viewed from the carbs intake side. I'll attach a couple photos. Thanks.

 

the float bowl drains are different than the 900 Seca and you have one bowl different from the other 3.
Strange...

 

Yah I think one of the bowls is off something else but it does line up with everything ok. The other bowls are different but again it all lines up. Odd that it would fit so well if it’s off another bike.

 

If they are from some other bike it would be good to know what other bike has same carb spacing

 

Sometimes.......not often but sometimes....you can still read the ink stampings on the sides of the carb bodies. These can be hard to read if the carbs are covered in gunk, and fully missing if the bodies have been dipped. But if they are still visible, they can help you ID what the carbs came off of (assuming it's a Yamaha). That odd idle-speed control screw looks like it's off BS34 series carbs as used on the XJ1100 or XS1100, as does the odd "center-bottom of the bowl)" drain screw........however, the 900 and the 1100 carbs do not share the same bowl gasket, which typically means that the bowls are not interchangeable.

 

I can't see any ink markings. Here's a couple pictures of the odd set next to a partially disassembled stock set. The odd set also has a vacuum port on one carb body, carb outflow side. I'll put a picture of that.