83 carbs on 82 engine?

[zayanteman]

As I brought up in Mods and Accs, I want to fit my 83 carbs onto my 82 Vision.  

Lucky says he capped off the fuel return lines with no problems.  I would think that preventing the fuel from draining (like the 82 carbs) or returning to the petcock (83) would cause some overfilling of the bowls.  No?

Kenny says he has put on 83 carbs without problems as well (except for having to grind down the aft engine mount a bit), and reports no problems with the vacuum hoses.  Are the fuel return lines and vacuum hoses the same?

So my questions to everyone (just refer me to other postings if you've already answered these questions elsewhere):

1. Do 83 carbs fit on 82 intakes (rubber boots) without any problems?  I read that Yamaha changed the intakes on 83s.

2. Do 83 carbs require 83 exhaust headers (different internal diameters)?  I would expect that Lucky and Kenny and others have not switched exhausts to match their carbs?

3. How much better will 83 carbs make the bike run?  Do they affect low rpm stutter, idle, gas mileage, power?  What have you noticed is different?

4. Do the 83 carbs need to be rejetted?

5. What would happen if I ran K&Ns (sans airbox), 83 carbs, 82 intakes, 82 engine, and Predator race exhaust?  Sound like this would screw things up?  Ron says his predator (non-race) exhaust did not require rejetting.  What do you guys think?  Some of you have swapped out the airbox for K&Ns, some of you have probably put K&Ns in the airbox, and some of you have done the carb and exhaust stuff.  So let's put our minds together for the greater good of the Vision community!  (and for my bike)

6. What low speed screw settings do all of you use?  On my 82 carbs, I'm three full turns out from closed shut.  

7. If my bike is getting 35 miles/gallon, is it running rich, or just getting pushed hard?  Sometimes it won't start due to flooding, so I let it turn over for 10 seconds or so without pumping the throttle.  Then it fires up.  Floats are good.  What's going on?

8. What kind of mileage are you guys getting?  82s, 83s?

[Rick G]

I would not recommend doing away with the air box, The carbs on a V are largeish for the displacment,  and as a concquence the low velocity of the air at low rpm does not allow for a proper mixture. To correct this, Yamaha  came up with the flapper in the airbox inlet. By restricting the air flow Velocty was increased and the  mixture corrected. The diaphram gradualy opens the flapper as engine rpm rises. You can change jets 'til your blue in the face , with out the flapper you peeing into the wind.