YICS Disassembly

[Jimustanguitar]

I have a leaky YICS unit and will be repairing it soon. I do not have access to the bandsaw at our shop every day, and was curious if the unit has a glue joint down the middle of the unit that seperates the two chambers? My idea was to use the little cut off wheel on my Dremel tool and just go around the perimeter of the box, and then slide a hacksaw blade in the middle to cut through the divider wall in the center.

Would that work? Or do I really need to use the bandsaw?

[reckon]

your method you are describing will work, you will need to take each half afterwards and "flatten it" on a piece of sandpaper if you expect the surfaces inside to seal (a hacksaw will not give you the straightest cut)

or wait a little bit and get a BRAND NEW YICS:    :o





the pics are the first prototype casting, and it FITS perfectly,...the trouble is the urethane compound I used to make the proto gets VERY soft at operating temp, and the first unit actually imploded!

I am going to try pouring an epoxy/ chopped kevlar resin, and use flared brake line tubing set into the plastic for the nipples on the back side.

the chrome covers are more than a month away (I don't even have a casting taken yet)

ROV member sell price should be something like $40, or $60 including the chrome cover.


I have 2 old OEM YICS units, and they are DAMN HARD to repair, the old PA6 plastic (nylon) is just SATURATED with fuel residue, and getting good adhesion (and a tight seal) is nearly impossible, which is why I decided to take the $150 hit on silicone casting/molding materials, and start making my own.

the 83 windscreens I am working on have 1st priority, but the YICS (RICS?) will be next, probably about 30 days till I have working, tested units.

(PS my bike runs AWESOME without a YICS, and the nipples capped up so this is definitely an OPTIONAL resto)

[Jimustanguitar]

After that, you need to make new intake manifolds!!!

Looks great, I've thought about making one, but don't have much experience molding plastics... The trick may be using a thermoset plastic that wouldn't get soft at operating temp.

Don't listen to me though, some things are better left to the pros, you know?

[reckon]

After that, you need to make new intake manifolds!!!

Looks great, I've thought about making one, but don't have much experience molding plastics... The trick may be using a thermoset plastic that wouldn't get soft at operating temp.

Don't listen to me though, some things are better left to the pros, you know?

the epoxy I will be using is fuel grade (aircraft gas tank liner) and the chopped strand kevlar should be WAY overkill as far as rigidity is concerned, same with the aluminum nipples,  I just actually have to MAKE the things.

as far as carb boots (intake manifolds) go, that's going to have to be a vulcanized item (aluminum mold, silicone compound and bake it) as there isn't an RTV (room temp vulcanizing) silicone or rubber that would work.
(PS my "liquid electrical tape" fixed ones are still tight after 2 years now)

and after nearly 35 years fabricating plastics, I thought I WAS a "porfesh-on-ull"   :D

[Jimustanguitar]

I was saying that you are the professional... I'm not.

Sorry if that read wrong.


I am going to try making a metal flange with a tube that is the correct dimensions to replace the intakes, and then try and find a fuel resistant 'radiator hose' of sorts to hose clamp the carbs on. I can just use a well made gasket under the metal flange to seal up the lower end then.

Let you know if it works... Probably won't though :)

[reckon]

I was saying that you are the professional... I'm not.

Sorry if that read wrong.


I am going to try making a metal flange with a tube that is the correct dimensions to replace the intakes, and then try and find a fuel resistant 'radiator hose' of sorts to hose clamp the carbs on. I can just use a well made gasket under the metal flange to seal up the lower end then.

Let you know if it works... Probably won't though :)

;D ;D

I was just givin ya a hard time, (something I am PATHOLOGICALLY incapable of stopping), it's all in good fun.

I don't see why an aluminum tube with rubber tube "connectors" WOULDN'T work,.....I think it's a great idea

[YellowJacket!]

My method is tried and true...at least for the 4 or so YICS I have rebuilt. Part of the credit goes to Lucky for the gasket idea from his website.

Heres what I do:
1.  I use a sharp utility knife to score down the seams.  It takes a while but gives the straightest edge.  After scoring deeply enough to pry the two halves apart, I split the YICS.
2.  After splitting the YICS, I clean all the crap put of it (looks like Recons picture when I'm done)
3.  I use 80 grit sandpaper to flatten the edges perfectly. To do so, I tape the sandpaper to a flat area on my garage floor.  I sand in a circular pattern.
4.  Next, I use 150 grit sandpaper just to smoothen things out.
5.  Make a gasket for the YICS (lucky's site)
6.  Apply a thin bead red RTV to one half of YICS and place the gasket. 
7.  Apply another thin bead of red RTV to the other half, then clamp the two halves together.
8.  Wipe up the splooge ( the RTV that oozes out) and use it to fill any gaps.  Kind of like when you seal caulk around a tub or window.
9.  Let it cure for 24 hours.
10.  Hook it up, crank it up, and smile.

David

[Rick G]

I did one for myself , using JB weld , and it lasted 6 or 7 years , before it started to leak. I then solved the problem by plugging up the ports and tossing the YIKS box.  I used a set of caps from auto zone to cap the ports , but the rubber cracked in about two months (Chinese rubber) now I'm using a short piece of fuel line with a ball bearing shoved in it.

[funkamongus]

I did mine with red RTV, same process of cutting it with a knife, and lapping the edges to get seal on outside and interior walls... so far so good.. not really running her yet, though. but she seems to have no vac leaks..

[h2olawyer]

I did the gasket type fix several years (10,000 miles) ago.  Still going strong.  Used aviation form a gasket on each side of the paper gasket and I used spray adhesive to attach the sandpaper to a small piece of glass for lapping the seams.  Also used a band saw to separate the halves.  If (when) it begins to leak again, I'll probably repeat the same fix.  Or, I may just contact reckon and get one of his spiffy new ones.   8)

H₂O

[Kid Jedi]

I just cut mine apart, painted up the inside and edges with jb and called it good. thinking bout making a new system using a pair of sealed metal fuel filters from those little 4 banger sewing machine cars (honda civic...)

[Jimustanguitar]

I'm at the stage where I almost want to just ditch the YICS unit. I have not tried taking it apart yet, but I'm pretty handy with a razorblade, so I like that method the best so far. Really the only reason that I want to repair the thing is because I'm trying to figure out the stumble, and I know my YICS leaks, so I want to make everything I can control work properly when I Adjust the carbs for the first time after I pull them out of the dip. That way, I'll be at square one and determine for myself if I want to cap it off or keep it after I get everything else running smoothly.


I know people have said that they can notice just the slightest bit of difference with the unit in place vs removed and capped off, but has anybody had an experience where the YICS unit made a drastic difference? Obviously my leaky one is letting one cylinder's vacuum "talk" to the other cylinder's, and that cannot be a good situation, but how big is the difference between a working one and a capped off one?

I'm guessing that instead of delivering a charge of atomized air/fuel like Yamaha says the unit does, I think what Yamaha was doing what just treating the YICS units as expansion chambers in order to achieve a 'resonance' in a different place. 2-stroke guys deal with this all the time on their exhaust, I'd bet its a similar design.

[h2olawyer]

We've had a standard dure to get the bike running properly without the YICS before adding it into the complextiy.  It isn't at all necessary and even a hinderance when doing your initial troubleshooting.  Cap off the ports for now, make sure the carbs are spotless, the mixtures are set properly and they're well synchronized.  If you haven't already done so, remove the plug wires & clip off 1/4 - 1/2 inch from each end & reinstall.  Also put in new plugs & caps.  Inexpensive and eliminates those as a source of trouble.

These carbs are tricky even for those experienced with other carbs.  i've done carbs on vehicles ranging from a 62 VW Bug, a 72 Ford Pinto (don't laugh too hard), a Motorcraft 4bbl on a 69 Mustang - replaced with a Carter AFB, a couple of Quadrajets in elCaminos and the water cooled carb on my Toyota truck.  None were nearly as much of a PITA to get clean as the Vision's carbs.  Took me three tries to get them rideable - still had a little stumble.  Got a second set and worked them over heavily - no more stumble!  still have the originals that I need to try cleaning out again to see if I can get them right.

You will eventually figure it out & then you can tackle the YICS.

H₂O

[Kid Jedi]

its both. Long story short of the yics is that it shifts the power band a little lower, for even more jaw dropping low end torque. does it fix the stumble at 4k? No. The bike was designed to run with the yics system. but will run alright with out it.

[YellowJacket!]

I just cut mine apart, painted up the inside and edges with jb and called it good. thinking bout making a new system using a pair of sealed metal fuel filters from those little 4 banger sewing machine cars (honda civic...)

Right after I got my Vision about 5 or so years ago, I read about the YICS problems and found that mine was leaking like a seive.  I set out to create my own "updated" YICS or "UYICS" as I called it at the time.  I carefully measured the volume of each chamber and cut some copper pipe to length, capped it off and welded some nipples onto one end of each.  I painted them black and maunted them to the frame.  Although they were sealed tight, they still did not make any difference.  Maybe it was because of the flex or give of the plastic material, but they just didnt seem to work.  As it may have turned out, it was before Lucky moved to TN and showed me the error of my ways with my badly adjusted carbs.  As the story goes, the UYICS were taken off the bike and are now somewhere in my barn.  Maybe one day I'll give them another try.  At teh moment my current YICS is working great so I don't want to disturb the gremlins and mess with it.

David

[Night Vision]

I just cut mine apart, painted up the inside and edges with jb and called it good. thinking bout making a new system using a pair of sealed metal fuel filters from those little 4 banger sewing machine cars (honda civic...)

I'm not so sure that's a good idea. the YICS box flexes and JB weld does not stick well to them. you are risking the JB flaking off and getting sucked into the cylinder.

[Rick G]

Jason Morris has preached for years , here on the forum that the YIKS was designed for the 4 cylinder engines  of that era and was of some benefit on them. On the twin cylinder Vision it did nothing , but leak. I JB welded my own in '03 and it started leaking earlier this spring , I've tossed it and won't be reinstalling it.I have enough things to do to maintain the bike and won't bother with the YIKS box.

[reckon]

Jason Morris has preached for years , here on the forum that the YIKS was designed for the 4 cylinder engines  of that era and was of some benefit on them. On the twin cylinder Vision it did nothing , but leak. I JB welded my own in '03 and it started leaking earlier this spring , I've tossed it and won't be reinstalling it.I have enough things to do to maintain the bike and won't bother with the YIKS box.

I make the units for restoration purposes, and to be honest I think my V runs a little bit BETTER WITHOUT a YICS hooked up

it really is NOT a very big difference with or without, just make SURE whichever way you go that the system is tight, and NOT LEAKING, as that had more impact on how mine ran.

I will still be offering fully assembled improved units as soon as I get them made up (working about 6 hours a day now on V things)

[akvision]

Rick, have to disagree..

Why make 20,000 units and put a YICS on each one for no reason... Each unit had to cost at least a couple of bucks each , plus all the advertizing environmental   hype...

I think, if it was and exercise they would have dropped it in 83 with all the re-engineering on the systems an all.   

I think it was the emissions and standards requirements of the day.    Get ready we are heading that way again today as we speak.

just my opinion sake.

[Rick G]

Disagree if you like , but its the truth. Jason Morris explains it much better than I do, but hes is always dead on with his facts.