mis-matched carbs.

so while I had the tank off painting it, I thought I would try to fix my rough idle problem and clean/inspect the carbs.

after fiddling around with them for a while, I noticed that one of the carbs doesnt match all the others.

this is on an 83 750 LTD.

The floats are all the same on 3 of them, but one isnt rounded on the bottom like the others, and its kinda square and notched on the front and back side.

I dont know if they came like this or what, or if anyone has seen anything like this before on their bikes.

I don't know whether some "mechanic" said one carb is as good as another of the same size and it may be sometimes true. However, I think your pretty safe in assuming it didn't come that way. If you keep an eye on ebay, you shouldn't have a problem picking up another 4 of them.

I doubt that having mismatched carbs will make tuning or synchronization easier. The slide cut outs necessitate a certain pilot jet be used. If the slides are different (with different cut outs), you will not be able to get the bike to idle properly using the same size pilot jets. In addition, sync can become problematic when the wrong jets are used. Buy a new set if you intend on keeping the bike. I suggest Mikuni BS34s. Parts are more readily available.