83 carb installation on 82-Help Needed

[Dan_Byers]

After doing what I could to try and correct the severe surging and non-idle problems my V started having after last winter's storage (new plugs, drained bowls and flushed checked inline filter, checked petcock) the V fired up and still wouldn't idle and surged like crazy unless heavily gassed. I dumped a whole bottle of Valvoline synthetic carb cleaner in the tank, topped it off with 94 octane and hit the highway. About 2o miles later it started running better. Almost like before (this V has been PERFECT for 3 years carb-wise)except the idle wanders around now and sometimes drops too low where if not gassed it will die. Today it started the surging briefly again, then cleared out. I have only ran 70 miles on this tank with the cleaner in it, but am now convinced either a jet or something else is trying to clear debris floating around. Next to the drain screws are hex head bolts. If I remove these are the main jets behind them?..and should I take them out and blast in there too?
I will continue riding it through possibly another tank with another bottle of cleaner to see if it improves further...BUT...

I have a carb set off of an 83 that looks mint, and the previous owner I bought it from says it was drained and cleaned after the bike was parted. I know there are differences in the way the fuel line is run, with a t-fitting needed for the fuel return-to-tank line. Can someone who has actually DONE this conversion take the time to explain step-by-step the swapping over of an 83 carb onto an 82 engine.
If the current carb doesn't clear up, the swap might look inviting.
Thanks in advance for any insight.

[Lucky]

I have put an 83 carb on my 82 once for testing (i was rebuilding an 83 for someone) the install is exactly the same with the exception of the return line. if you can get ahold of an 83 petcock that would be the best thing, although i believe they mount differently.  without the petcock, and easier, you could tee into the fuel line between the petcock and fuel filter (you would be double filtering your fuel, not a bad thing!)
you will need to resync  your carbs aand probably adjust the pilot settings a bit as well.
lastly, don't be surprised if the 83's need cleaning, unless he blew them out with air (all the passages) then there will still have been fuel residue left in there plus any sediment that was there previously...
--Lucky

[Dave T.]

If I were you, I would cap off the YICS ports and see if this stops your surging. Also get rid, cap off replace as many vacuum ports and hoses  as you can and see if it still surges. Then try getting a carb sycronizer and sync the carbs.

I capped off my YICS and no problems whatsoever. I would say you just have a vacuum leak at a fitting or in a hose. I also have my petcock vac capped off too. I produced a tic, tic, tic sound at certain rpm's. Removing the tic to me was worth the lack of fuel shutoff.  ;D

[QQBS]

The main jet are located behind the brass hex head bolt.  You can stick the small diameter plastic tube that comes with most spray carb cleaners into the main jets when these bolts are removed.  You can also power flush your float bowls with these removed.  Somehow high volume pressure feed fuel or carb cleaner into the carb via the fuel inlet line while the float bowl drain and maim jet access plug is removed.  Cheers.

[jasonm.]

If you install '83 carbs on an '82 the front jets will need to be changed. The '82 has different header pipes and this requires the change to smaller mains. Maybe a 125 or 127.5 in front. Maybe a change to the pilot air screw as well. You need to compare the jetting in the service manual to see what I mean.

[jasonm.]

Oh one more thing. Check that YICS box and hoses. That's the cause of many poor running problems than you can shake a stick at. The box will leak and should be tested with a Mity Vac tool.