Newbie questions

[Harold]

Got me a pretty clean Vision, 8k on the clock.  It will join several other bikes I have, fron CT-70 Honda to FXR harley.  While I ain't a newbie to bikes, I am to the vision.

The only annoying thing about the bike at this moment (other than changing sparkplugs) is the legendary mid range stumble, and that it won't idle worth a damn.  Since the bike setup for quite a while, I will 'boil' the carburetors.  My questions address this stumble.  I have read that yamaha sold a kit to eliminate this issue, and I've also read that the folks of "Riders of Vision" have a solution?

I'd sure love to hear about it.  When I got the bike I discovered a pretty good size vacuum leak in the hose coming from the rear cylinder.  Fixing that made some improvement in the idle, but the mid range stumble is still there.  There is a site on the net addressing the rebuild of the YICS, but can someone say whether the YICS is effective?  What would be the consequences of plugging it off and retaining the module for aesthetic purposes only.

Lastly, kind folk, is it likely that I will need a carburetor rebuild kit, and if so, where might I come up with one or two?

Thanks, great web site, BTW, mr Webmeister!

[sdinino]

Let's see:
 - the mod. kit Yamaha sold consists of a vacuum actuated airbox door that restricted airflow while the carbs crossed over from the low/idle circuits to high. Some people have found that their particular bike require further delay in full opening, so they've glued a nickel or nickels to the door to add weight.

 - 'boiling' the carbs is probably your best first step. These carbs are unbelieveably intolerant of any sort of fotch inside them.

 - the YICS debate falls into two general schools of thought: those that see no effect whatsoever from hooking it up, and those that see a marked improvement in performance when they do. Give rebuilding a try, who knows. You may see a difference. If not, simply cap off the connections on the heads. Plenty of us are riding that way with no ill effect.

 - the scoop on the rebuild kit is that they're no longer available. You can either reuse what you've got (the bowl gaskets, for instance, are normaly not needed) but you can make those fairly easily. Lucky can also whip some up if your not inclined to do so. As to other rebuild parts such as needle valves and seats, I don't know where you'd find those. Perhaps someone else does...

[Lucky]

the site you saw was probably mine, Vision Resources, at http://www.geocities.com/lucky_142

yes, dip the carbs, eliminating the stumble is a matter of clean, well adjusted carbs with no vacume leaks, return everything to proper working order before trying the "tricks" very often this is all it takes to eliminate the stumble. i offer a Vision carb rebuild service if your so inclined
--Lucky

[dav]

Also remember to sync the carbs.  I had a surging idle after cleaning carbs because the carbs were about 1 1/2 turns off on the sync rod. These are mikuni carbs so they share some of there parts with other models.  I got the needle seat o-ring at my local suzuki dealer because most of the mikunis use the same size 0-rings. just match it up.  There are also a few places i have found on the net that sell hard to find carb rebuild parts.