83 Carb Help!

[inanecathode]

So im finally steeling myself up for the task of taking the carbs out of my 83 and giving them a good cleaning and servicing. My bikes been running worse and worse, and i know it can be better. Afterall it came out of the factory running perfectly why shouldnt it now?

Essentially thats my question. It's got a cruddy, slow return, but an idle. Its poppy when i hold the throttle even, when im wide open its fine. High load reasonably low rpms it'll kinda choke out and run poorly until it hits 7k, once its at 7k hold on to your hat. Add ontop of that the poor running at higher coolant temperatures and i've got a finicky beast!

Back to my original question though, it came out of the factory running perfectly, why isnt it now? More specifically, what goes wrong with 83 carbs? I understand how the 82 carbs work pretty well, but i hear tell that the 83s have all sorts of cool doodads and doohickeys to go wrong/seize, rot etc. My carbs should be clean, it's not acting like they're dirty, its just acting... strangely. I think i might have parts of a rebuild kit for 83s kicking around somewhere so, all i need is some sage advice on how to tear into these things without borking them up completely, and what to look for/check for/watch out for.

Lucky?

Thanks,
Cathode.

PS: I dont have any vacuum leaks, i have no yics to leak, the carbs are synced and tuned the best i can get them, the ignition system is working perfectly and the spark plugs are a healthy caramel brown with a good heat range and everything :)

[Walt_M.]

Bad gas? Drain it and check for water.

[Tiger]

 :) You need/gonna need...

http://cgi.ebay.com/ebaymotors/YAMAHA-XZ550-VISION-KEYSTER-CARB-KITS-1983_W0QQitemZ140257991952QQcmdZViewItem?hash=item140257991952&_trkparms=39%3A1%7C65%3A1%7C240%3A1318&_trksid=p4506.c0.m245

                8).......TIGER....... 8)

[Lucky]

Welcome to my world! don't step in the gremlin turds...

ok, first off the carbs aren't all that different from 82's in construction, just design.

my only 'don't break it' warning: (besides the floats/ posts) is the control valve on the rear carb over the accel pump.  udo the 4 screws on the top, note the order of things as it comes apart. there is a spring in there, iirc, so lift the top off slowly. the sandwich plate in the middle with the flat o-ring: dont take this apart unless it's damaged that is the brass screw that breaks.

other than that, the only common 'problem causer' i've found is that smaller problems that wouldn't seem to bother an 82 make an 83 run like crap.
it sounds like an idle/low speed curcit issue.  if you have macs that'll help narrow it down to ft or rear.

to get the pilot screws out, carefully drill out the plug & pop it out with a sheetrock or metal screw, vicegrips & hammer. you can just silicone over the plug when you put it back in. this'll show you what plug to remove: http://www.xz550.com/83mix.html

pay particular attention to the pilot jets, accelerator pump nozzles, accelerator check ball (with the rear top off & gas in the bowl, does it shoot bubbles back into the bowl?) blow thru the passages.

yell if you get stuck, or i'm home today (i'll p.m. you my ph#)

--Lucky

[Lucky]

unbelievable, they were asking $80 + for the 2 kits & f/pump earlier this year.

someone grab all 12! (might be all that's left)

[Brian Moffet]

my only 'don't break it' warning: (besides the floats/ posts) is the control valve on the rear carb over the accel pump.  udo the 4 screws on the top, note the order of things as it comes apart. there is a spring in there, iirc, so lift the top off slowly. the sandwich plate in the middle with the flat o-ring: dont take this apart unless it's damaged that is the brass screw that breaks.

http://www.pbase.com/moffetb/image/94197647

I believe that is a series of photographs that is rebuilding the pump that Lucky is talking about.  I was extremely careful (and took a lot of time on the rebuild) to make sure I didn't break this.  If my bike had been outside rotting for years, it would probably have been much worse.

Ignore the other photos that crop up, that's the website being strange about numbering the photos...


Brian

[jasonm.]

Another word of warning. The emulsuion tubes.  The damn tops are easy to break when tighening them into the carb. I KNOW. Best advice is to use a whimpy undersized screwdriver for these after they are confirmed clean.

[inanecathode]

I'll have to temporarily have the vision on the back burner, i've got to get my car ready for cold weather first. Afterall i cant ride the vision in foot deep snow ;)

I'll return to the thread (if) when i get time to get the carbs out and start breakin stuff :D