rpm better but whats with the smoke?

[fiddlesticks]

Today we removed the yics, and went directly from one cylinder to the other. Immediately the rpm stopped shooting all over the place. Took her for a test ride where she decided to stall at stop signs. ?Putting out lots of black smoke. We pulled the plugs and replaced them with the ones we took out from last year which were in perfect condition. The ones we took out this time were burnt black. Why is she running so rich? We injected carb cleaner into the float bowls and reconnected fuel lines hoping that would work its way through, but it had no affect.

Thanks
Fiddlesticks

[Superfly]

When you connected the cylinders, you created a huge vacuum leak.... Cap off the hoses instead of connecting them together.

[Blake]

Not necessarily..


I have had my YICS off and connected the hoses and havent had a problem with it at all...


Did you recently fill the bike up with oil?  perhaps you overfilled it and its now burning the oil thats being shot into the airbox?



Just a thought,
Blake

[Lucky]

it's not exactly a vacuume leak when the 2 ports are connected, it's more like a vacuume leak with fuel mixed in.  basicly what your doing is moving the sucking mixture out of one intake & shooting it into the other cylinder, and vice versa.  it should have a detrimental effect on performance, but some who've tried this say no, and some say absolutly.

since it's not working the way it is you should cap the ports & see how it is.  Personally, i find the bike starts & performs much better with a working YICS...

--Lucky

[fiddlesticks]

Eventually our goal is to put a working yics back on. We only removed it to eliminate that as a cause of the spurratic idle. Which it seems to be as the idle has evened out with it off. So the problem now is the smoke and burnt plugs. Are you saying the smoke is caused by the hoses being run from one cylinder to the other?

[h2olawyer]

fiddlesticks -

Your black smoke could be from a couple different causes.  The ones that come to mind are float level set too high, misadjusted mixture screws, leaking needle & seat.  There are probably some other causes that will be mentioned.

Like Lucky recommended - cap off the YICS hoses for now - until you get your YICS box fixed.  The YICS helps both starting & performance when they operate correctly, without leaks.

Good Luck & Keep us posted.

H2O

[fiddlesticks]

Does anyone have a spare yics theyd like to part with. I have just verified that my box is toast. Its leaking terribly.

[h2olawyer]

The YICS is a notorious failure part.  Most - if not all - will begin leaking at some point in their life.  If someone doesn't have a spare fixed one, you can repair yours fairly easily.

One methos is posted on Lucky's site.  http://www.xz550.com/YICS.html  This is the method I used and it's leak-free after two years & about 2,000 miles.  It is very important to get each mating surface as flat, smooth & even as possible.

There is another way to fix it.  As I haven't done the "hammer" method, I'll let someone more familiar with breaking it open explain how its done.

H2O

[EH]

Visions have an enrichener circuit for starting as opposed to a choke. An enrichener mechanically opens an orifice connected to the fuel feed circuit and dumps droplets of fuel into the throttle bore for starting. I will bet your choke cable is maladjusted or hanging up due to corrosion within the cable. Lubricate the choke cable and adjust the choke cable according to any manual available. Let me know if you need Haynes or Yamaha directions for the adjustment cuz I have them. A choke manipulates the throttle plate ( closes it down irregardless of throttle position) and allows the absence of air to create the fuel rich mixture needed for starting. Also, when I bought my Vision, whoever installed the carb upgrade installed the carbs wrong and my throttle plates were hanging up and not closing with the throttle. That was fixed the day I bought it because I went right back to the dealer and observed what they did. Don't give up!

[Lucky]

how did the carb update affect the throttles? carb update consisted of ft carb top & small filter, rear jet & airbox top.  what part of that did they screw up to make the throttles stick? did they screw up the synq or something?

[EH]

They removed the carbs to perform the update and installed the carbs without seating them in the indents in the rubber boots that receive the carbs. This caused the rear throttle plate, which is low in the throttle bore, to not fully close.

[tremalzo]

Last year I disconnected YICS directly connecting both cylinders with a piece of gas hose. The bike had a complete tune up before but still was running rough. After disconnecting YICS I got a better start, immediate control of the rpms and could turn the idle speed wheel on the carb way down. Didn't even bother to reconnect the YICS box. It runs fine without, no vision-stumble and the same gas milage as before. If there is any difference, I couldn't notice.
 
Last week I started the bike after its winter sleep. Same sparks, only carbs drained. It started in 3 secs.

Cheers,
Tremalzo

[fiddlesticks]

Ok now Iv got huge problems. I sawed my yics in half as per the instructions on Luckys site. It still leaks. Tried to open it up to try again, and fubar'd it up. It is now garbage. So now I need to buy one. Does anyboday have on they'd part with.

[troy]

i noticed somebody had an aftermarket (or something) yics replacement on here ill see if i cant find it keep your eyes open. maybey somebody knows of it

[troy]

did a little more research for you found that thread : http://www.ghetti.net/cgi-bin/ROVBB/YaBB.pl?action=search2

its called ogre snot. heh i guess. it wasnt posted very long ago maybey you can find some more info on it im definately interested!

[troy]

my bad turns out he fabricated that yics out of fiberglass (whoda thinkit?) sorry to be unhelpful

[ps2/bikevision]

ok this may not help but you said you had the carbs done. did who ever done the carbs set the jets to run without the yics. this was just a thought.