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1994 883to1200 sporty XLH. Only idles at full choke

2K views 14 replies 8 participants last post by  Trials 
#1 ·
Hey guys! New here! Thanks in advance for anyone replying!
Been doing all my own work on an old sporty that was given to me. All that’s really left is to get the damn thing to run properly!
I dismantled and cleaned the carb. Cleaned the jets and all that. It just won’t run on anything but full choke. Soon as the choke closes( it’s a spring loaded choke so it closes automatically)
The bike sputters out. The lil plastic screw-in part where the choke connects to the carb body is chipped... but the rubber boot covers it well... so I’m lookin to replace that.
It’s taken me a year of working on this bike all on my own and this is the last thing on my list of repairs.
Please Obi-bike kenobi ... your my only hope.
 
#3 ·
That's a CV type carburetor, it does not have a choke that restricts air flow, it has a fuel enrichment circuit. When you are using the "choke" you are adding fuel directly into the intake, that clearly indicates your normal fuel circuit is not getting fuel.

Looks like your main jet needle valve is height adjustable from the part diagram, what position is the cir-clip in currently? part 11&62

good chance part #13 is plugged, it needs to be clean like a gun.
 
#11 ·
Ok so the brass piece that shoots fuel directly into the intake barely spits any fuel. I watched a vid where it shot a stream of fuel, mine is more of a sad spurt. I think I need to remove it and clean it out? Just not sure how to. I’ll look on you tube
I’m not sure what the cir-clip is but I’ll look into it once I get home. Thanks!!!!!!!

“The path to hell was paved with good intentions.”
 
#4 ·
Welcome from Kansas!

Is this a recent big bore kit issue, or a big bore kit that was previously running fine, but suddenly isn't?

If the former, you may need to fatten it up a bit, though I don't recall my buddies 93 needing anything upon initial install of the big bore kit.
 
#5 ·
Some day you will all develop the same hate on for CV carburetors that I do. It has to be the worst design that ever found its way onto a motorcycle, thank goodness for fuel injection. Now all we need to worry about is motorcycle manufacturers making their fuel injection systems vacuum operated.
 
#6 · (Edited)
Some day you will all develop the same hate on for CV carburetors that I do...
Love `em or hate `em... for my money (never much), the CV40s were/are one of the best carbs made -- at least for V-Twins. Had on Harleys as well as my `99 Nad... very hard to beat, and pretty simple as well... Although it is possible the fuel delivery is still dirty, I'd also check for air leaks, lots of places where that can happen -- and full-choke often seems to "correct" it... especially on the V-Twins... (ask me how I know that... hmmm... :cautious:)
 
#7 ·
Well now! I heard carbs 4 the Sporty of which I have 1 are very finicky. Might be the reason
someone, put an S&S Super shorty I think its a G carb on my bike. I never, whooops just
1ce had an issue, low speed circuit, ran 4 oz of Seafoam through it, sat in the carport with a
few beers, well maybe more than a few but it was raining. . . anyways, the next day the bike was
running just fine I do make sure to keep that air filter serviced as I gained twenty more miles an
hour just by cleaning it..
 
#8 · (Edited)
If fuel treatment or gas line anti-freeze solves your carburetor problems, you most likely had some water in the bottom of the float bowl.


Constant Velocity carburetors are the epitome of carburetor design complexity. They came about because engine builders were compelled to produce machines that consume less fuel.

Air leak? Well if it's a vacuum leak yep, that will certainly mess up a carburetor that requires vacuum air pressure to open the slide instead of a cable.
 
#10 ·
Usually when choke is required to run, the small jets are restricted or blocked.
The CV carbs are great when they work. Are a real pain when they do not work properly. I have both.
I prefer the older Mikunis, where the cable lifted the slide. I am not crazy about these enrichener devices.
But my XS1100 runs great, my XS400 not so much. Jetting is the issue with the 400. It also has another funny thing in the combustion area that makes plug ready difficult. Never hurts to remove all the jets and peek thru them. UK
 
#12 ·
Your carburetor appears to have a very small plunger pump fuel circuit on it. part#33 etc.
that might be activated on deceleration or acceleration and was likely put on there to stop the bike from stumbling or stalling.

The brass parts have precisely bored holes in them, clean them like you would clean the worlds smallest gun. Microscopically if possible. There is also a thing called an emulsion tube, that is a brass tube that has small holes drilled in the sides of it. That needs to be perfect too or it will spray lumps instead of a nice fine mist of fuel into the air flow.
The whole goal of the carburetor process it to atomize the fuel as much as possible.
 
#15 ·
You haven't given us much to help you with and unless you ride a 1994 883to1200 sporty XLH you would be far better off to start a new thread. & what do you mean turn the gas all the way on, at the throttle or at the fuel shutoff valve or on reserve as opposed to on or off, and where is gas running out of a rubber overflow tube or out of the fuel tap or out of the carburetor body?
 
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