Stumbles under load in higher gears

[Armored_Hearse]

I am slowly getting things sorted out. The biggest one so far was getting a complete airbox that had the vacuum flapper, as someone decided to remove the entire assembly from mine.
Anyway, it runs well now with the YICS removed and the flapper connected and working, but...
The latest quirk is that acceleration in 1st and 2nd is nice and smooth through the shift point, but under loads in 3rd, 4th and 5th is starts to stumble in the upper rpm range. It gets worse as you move up in the gears. In 5th it loses that quick acceleration above 50MPH.
I think it's time to go through the electrical (connector cleaning, new fuse box) and replace the plug wires (Tiger, expect an email soon). Is there anything else I should check or be looking for? Maybe an official carburetor cleaning? It did run great right after I installed the airbox, but after adding about a gallon of fuel it started acting up.

Update: Rode today (54 degrees F) and noticed it is mainly in 5th accelerating around 5500 rpm. Maybe I'm just not keeping the rpms high enough?

Thanks in advance for any ideas!
John

[sunburnedaz]

The bike should not stumble in gear. I cruised the other day in 5th at 4000 RPMS with no stumble. I would say carbs since these bikes from what I am told can deliver way more air than they do fuel. I would think that its not getting fuel delivery that it wants so all the passageways need to be cleaned of gum and varnish and dirt that has most likely built up there.

Now for my disclaimer I am new at this whole vision thing but I did get mine one the road after rebuilding my only set of carbs. Someone might come along and correct me and there words should be taken over mine.

[Lucky]

at 5500 you should just be hitting the power band.

absolutley clean those carbs!

[Armored_Hearse]

That is what I was thinking but didn't want to accept the reality of rebuilding the carburetors. It has me a little nervous that I may make a mistake.
Cold weather has officially set in and I doubt I'll be out riding until March. The tank and carbs will come off soon and the real work will begin.

At least I know I have some excellent resources to get me through anything that may come up.  --  John

[Lucky]

rebuilding these carbs aren't that hard, just take it slow, lay things out logicly, take pictures, draw diagrams, ask questions.  call us when you get to removing the acclerator nozzles...

--Lucky

[YellowJacket!]

At least with the winter months upon us you can work slowly and methodically without feeling the "rush" to get out and ride.
Its not so bad taking htem down to clean them and put them back together as long as you are careful.  The biggest problem will probably be getting the screws out that hold them together.  The second biggest problem will most likely be getting the jets out.  Just be very careful and I echo what Lucky said about laying things out and documenting.  Be patient when asking questions...you'll get an answer.  It may not be right away, but you will get one.

David

[Armored_Hearse]

I have started the winter breakdown. Battery is out and seat is off. Somehow the fuse for the headlight has blown, so it's good I'll be changing the fuse box and inspecting the wiring. 
I'm actually excited to see how good (or bad) the carbs look. I have lots of small part boxes to keep everything organized and a great place to take photos. writing assembly manuals is my line of work, so this should be easy dcumentation. I also have Lucky's phone number so I can get a quick answer if I get stumped.
After my short rides with the bad carbs, I'm excited to see what she can really do! Thanks for the encouragement!

[QBS]

Be carefull not break off a float pedestal if you attempt to remove the float needle valve.

[rhpaw]

You know, that stumble is exactly what mine felt like when I had those two lines mixed on the front carb going to the flapper..
http://ridersofvision.net/rovforum/index.php?topic=10457.0

After going though everything else twice and still having issues I found that.. J@#$! C$#@! the vision is CRAZY FAST when sorted out compared to a neglected one.

[Armored_Hearse]

I decided to open the carbs and clean them up. After opening the front carb it's a wonder it even ran! I'm wondering what the rear carb holds.
The front is about half-done. Lucky has been coaching me along with the tear-down. Still need to soak the lower half and reassemble, but all the other parts are ready. I am going to buy some new hardware as the screws are in pretty bad shape. (Not my fault, honest!)
I did buy new jets, but still need a 127.5. The ones in the front had no visible markings, so I thought it best to get the right ones for the rebuild. Only stopped at one motorcycle shop, but there are two more in town so I think I can find it easy enough.
I also have a set of plug wires on the way from Tiger. Since the tank is off, and the wires are of an unknown age, may as well replace them. They're easy enough to get to, so it only makes sense.
I still have a few other items to take care of, such as a good connector cleaning, replacing the fuse box and swapping out the front brake line. It may need a front fork rebuild as I think one is leaking. Maybe even a progressive springs upgrade. ;) At least it has new tires and fresh oil in the engine and shaft drive.
I had a Vision about 20 years ago and remember it was quick, but it had lots of problems that I could not take care of financially and had no space for repairs. I'm excited to get mine sorted and ready for some rides. Just looking at the specs, the horsepower of our Visions are better than quite a few of the modern bikes of similar size.
It's nice to be older (40's) and have patience and a place to work. The RoV board is also a great place for information which was not as available back then. Lots of encouragement and people that have "been there, done that" that you can ask questions of.  --  John