Butterfly "thingies" on 78E

[Espiritus]

Hey, all! Now that I am over my personal pity party and willing to go back out to the monster, I recalled another question that I had regarding those "butterfly thingies." I was looking closely at mine after I read a thread about a gasket or a seal that they seat into, and there aren't any. Is this another one of those "parts" that the 78E didn't have or was that a misprint on the thread? Also, one of my butterfly thingies doesn't appear to properly seat in the carb, just alittle "off" but noticable without using my magnifier. Can these be replaced and where does one find replacement parts?

Went and bought a solder gun and tried to locate shrink wrap. Where do you guys get that stuff?

Ordered a replacement starter button today. . .although as ugly as this bike has been acting I don't think I should reward it by removing the duct tape that is holding the old one on. . .

. . .too bad this monster isn't like Stephen Kings' "Christine" . . .I would love to go out in the morning with my coffee and see it all nice and polished and RUNNING! Wouldn't hear me complaining.

Whine, whine, whine, whine, whine.

Cam

[mro]

Item #38 2A2-14997-00-00 SEAL



Shrink wrap.... local hardware store and most auto parts stores altho mine came from Granger


mro

[prometheus578]

The seals... are on the ends of the shafts that the throttle plates rotate on.
Now.. when you say dat one o' da butterflies taint seatin' properly... do you mean that it doesn't look like it's closing all the way?
When you're done with your carb work, you'll need to synchronize your carbs.
What this does is, by turning those three screws between the carbs, you get all the throttle plates to open at the same time. If one carb looks "more open" than the others, then it's out of synch.
The throttle plates WILL be open just a little. If they weren't, then the bike would get no fuel at idle.

[Espiritus]

It's WHERE?

Guys, my Number 38 in the book is a "choke lever plunger" which just don't sound much like a "seal" to me! But, I gather from your note that it is something on the outside of the carb, on the shaft that the butterfly is mounted to, and not a full throat seal that the butterfly itself seats against to completely close. That makes me feel better already.

There is also a thread that speaks of a pressed in jet on the carb near the half-moon top air intake. I have looked inside that little hole and there appears to be a BB size unmoveable thing in there that has no opening. Is this also an abberation in the 78's?

Finally, in the book there is mention of "Note: Do not lose the two small steel positioning balls on the outboard carburetors when the shaft is removed." Trust me, there were NO balls. Either the PO lost them, or the 78E didn't have them (now why would I find it funny that a bike I would buy wouldn't have two little balls? Must be that double X that I carry or the time of day that I am writing this note).

Prom and MRO, I do appreciate you guys trying to guide me through this. Couldn't work on it today as I had to go buy that shrink stuff, and find my dremel. . .will be out there first thing in the morning.

Cam

[prometheus578]

You are correct about the butterfly shaft seals.
Now then....
Looking at the intake side o' the carbs... On the "E" model, you'll see three holes. (later models have four... the fourth hole at the upper right. This is a vent for the float bowl. Earlier models, such as yours, use that plastic "tee", with the hose venting to the airbox)
Anyway...
Those jets on the bottom are air intakes for the main and pilot jets.
The hole you're speaking of(upper left), is to supply air for the enrichener circuit, commonly called choke)
There are no "pressed in" jets there, just a hole/tunnel.
Oddly, though not a BB, the bank o' carbs I had laying around to look at also had a chunk of crap inside one of it's holes.
Hhmmmm....
Piece of dirt, spider parts of other stuff like that.
Whatever it is should be blown out.
I would recommend blowing it out from the other direction to not force it in further.
Get a can o' carb spray... or an air compressor if you have one.
Remove the cap from the top o' the carb and the vacuum diaphram.
Ok, now, on the engine side of the carb, in the throat, up at the top is a slash cut hole. This is where the fuel mixture from the choke comes out. Stick the straw from the carb spray in there(or the compressed air) You will need to have the choke lever pulled out and also need to place a finger over the choke related hole that was underneath the diaphram.(You'll see what I'm talking about once the diaphram is removed.
I would also recommend removing the float bowl for that carb. Those brass floats are very thin-walled. Doesn't take much to collapse them and conpressed air pressurizing the float bowl could do it.
Also.. that tube thingie sticking down from the carb.. that dips into the float bowl... That's to supply fuel for the choke. Carb spray will come shooting out there, as well. (And yes, there's a hole in that tube, not just at the end, but also up where it mounts to the carb body)
Anyway.. experiment spraying into different ports and jets till the offending plug blows out.
Unless you know where every tube, tunnel and port exits at, wear eye protection.
(If you haven't already gotten a squirt of carb cleaner in your eyes... it's a treat.)

[mro]

I find it funny that a bike I would buy wouldn't have two little balls?

All the XS carbs have balls....(XSept maybe Proms, think his bike is named Shirly or some such )
Your book was referring to choke lever shaft.

A parts break down is available here:
http://www.yamaha-motor.com/sport/my...starthere.aspx
Do not need to register, click "proceed to parts catalog" and use the drop down windows to enter info for bike parts.

Butterfly shaft seals normally are ok unless you have soaked your carbs in a cleaner for awile, just spraying carb cleaner should not hurt em.

There is a pressed in jet located inside the float bowl itself so you will want to remove the bowl to get to it.


mro
BTW
The pilot screws if screwed in to far or tight will break off the pointy end inside the carb body. All this info is in the tech tips.