I meant to say an '86, not that there would be any difference that I know of.

I have been having issues with the carb collecting gas in the throat area next to the air filter. Also earlier this year I replaced the compliance fittings because they needed replacing and have developed a hesitation when taking off at wide open throttle.

I rechecked the intake seals and they seem to be sealed well enough to not be effected by misting carb cleaner over them.

I tore the carb down and washed the main passages both directions with carb cleaner making sure the connecting channels came through the outlet ports, and reversing the spray wash. I removed the jets, and simply flushed the channels where the bleed tubes are. I also used compressed air to attempt to clear any debris. I've even disassembled and inspected the accelerator pump diaphragm, and visually can see the output squirting when twisting the throttle.

The bike has an EV 27 cam, K&N free flowing air filter and most likely stock pipes, maybe different baffles, it roars more than stock when you crank on the power. Also I added a Crane Hi4e a few years ago (really appreciated the improvement from this)

Carb is stock jets still with a 50 and 175. This set up had worked well without a situation for quite some time after all the improvements.

I just replaced the plugs, the ones I removed looked perfect, and I replaced the plug wires. Coil, timing sensor and ignition module change over just 2 year ago. I reset the timing and it's perfect. It has a lot of pickup and power with only a slight 4 or 5 quick hesitations (stumbles?) under wide open take offs, but recovers and speeds up very quickly. There are no other hesitations, or carb coughs or backfire issues.

My issue is in first gear, and sometimes also in second, I get several quick hesitations when I take off, while gaining speed, at wide open throttle. No problem if I roll it on quickly to full throttle. It's only when I'm taking off with wide open throttle.

One other troublesome issue is gas collecting in the carb throat in and around the air jet tubes inlets located closest to the air filter. It "seeps" gas in this area when idling, and "spills" a fair amount of gas when quickly accelerating to the point of pooling and dripping into the air filter. You can even smell raw gas when you snap the throttle to wide open.

I've been precise at setting the float which is new along with the valve. I even took q-tips and brasso to polish the seat and chamber where the float valve glides. Once I polished the area, it took several more q-tips to remove all the blackened rubber from the valve tip dissolving and the oxidation in the chamber for the valve. It shuts off the flow perfectly again ... for now.

When I tore down the carb there was not any notable debris in the bowl. But I've gone through the carb dozens of times with overflow issues in the past.

I also removed my new pingel and flushed the tank. There was a very minute amount of debris on the screen, and in the glass jar after washing down the tank.

Here's where I question what is going on:

Could the check valve for the accelerator pump be lodged open? (I overlooked attempting to flush this out with carb cleaner.)

My thought is this is where the gas is seeping into the carb throat by the filter. Even though I can see it squirting a good stream when pumped might this valve be the issue? How do I check it, clean it, or replace it?

I also wonder if the gas is seeping back out the air inlet tubes for the main air jet and the slow jet in the carbs venturi area? Even though I removed the main and slow jet I can't be sure if the bleed tubes are compromised by debris. Would a blockage here disrupt the gas air mixture and cause it to seep into the venturi / carb throat area nearest the filter? Is the main jet's bleed tube removable for cleaning? Is it even an issue?

I'm wondering if I need to simply adjust the Idle air mixture either in or out to stop the hesitation I have while gaining speed at wide open throttle? I found the idle to smooth out at 2 turns out. If I continue to adjust it out it seems the idle keeps increasing slightly. After about 4 to 5 full turns the idle gets rough again. I left it at 2 1/4 for now.

Please don't tell me about replacement options, I don't have a lot of money to work with and this setup has worked well in the past. I would love to convert over to a CV but I'm aware I'd have to locate the proper intake and convert to a later version throttle and cables, and I'm not even sure what it would take for the air filter to be attached correctly for this conversion.

Hopefully someone will know more about these particular issues. I'm hoping I can easily resolve the trouble(s).

Thanks in advance for your help.

 

IT's been awhile for me with the butterfly carb, but, the accelerator pump nozzle is pressed in only. Not threaded. Yes it can be removed by grabbing it with vise grips and twisting back and forth and pulling. I like to "spin" the nozzle with a wrench that fits the hex shape first to loosen the pressed in grip. But you still end up marking up the brass nozzle a little. It won't affect the way it works, but will be "scarred" from the vise grips. Make a reference mark first before you remove the nozzle so you can get it back in the same location (direction of spray).

Take it off, get it good and clean, take the diaphragm apart and check it for leaks and the condition of the spring. Clean the passage from the bowl to the accel pump. I think some models have a little check valve in that passage, and some don't. If you have a check valve in the accel pump passage, you usually can hear it rattle around when shaking the carb. Or if no rattle, you don't have one or it is gunked up. Just hit things with carb cleaner like you did with the rest of the carb. Double check that diaphragm.

I also recall something about the float needle and after market kits. Sorry it's been awhile, but, some after market float needles are not the same length as the original, so might want to check that closely with a magnifying glass.

Also, on your idle mix screw, are you sure your washer and O-ring are still in place? They are so small they are easy to lose. For isle mix you need the screw, spring, washer, and o-ring which needs to be round, not flat (they get flat) after awhile.

I agree, I think your misting, which is saturating the filter, and it is running down to the area your describing. It sure sounds like you have things clean, (except double check accelerator pump as mentioned).

That's my 2 cents for now, sorry, gotta go to work. Good luck with it, YD

EDIT forgot to mention, maybe ask this question over on the "classics" section as many shovels used this carb for awhile as well. Might get more responses/help. Also, is that black rubber plug in the carb bowl in place and not leaking? (they get hard with age). YD

 

That 50 jet seems a bit lean to me.

But to be honest, chucking that old butterfly in the bin and fitting a CV would make your life so much better.

Yeah, the Mikuni and S&S supporters are bound to chime in but if you want reliability and decent performance on a budget then CV is the way to go.

 

I had a problem like this when I "chucked that I the bin" this spring. Turned out the cables had come out of adjustment and the fuel from the acc. Pump was hitting the butterfly and comming back out the carb collecting where the filter connects.
When I changed to a cv (best bang for buck under 100hp) it was like a new bike and bye bye compliance fittings pos. I highly recommend ths upgrade you will not be disappointed.

 

Here's a video of the issue. It's posted on my Facebook account and available for public viewing. You can switch it to HD because I shot it with an HD cam, press the HD button under the player. FB says you don't need to be signed in to see it.


For the upgrade to a CV, am I correct that I need to replace the throttle on the handle bars and it's cables from a later model 90 - 95?

If I understand correctly the air cleaner assembly needs to be from a '90 - '92 without head breather design? Is it just the back plate that attaches to the CV carb that needs changing?

And the intake can be from 1990 and later? Not sure what the cut off year is? Did the intake to head contact point / seal insets changed from my heads to later models?

Too bad they don't make a kit to make it simple. Any leads on these parts or do you just buy them new at a dealer?

 

Dumping the Keihin is the best thing you can do. Get the whole setup with the intake manifold to get rid of those compliance fittings. Not sure when those changed, but 90 sounds about right.

 

Check the direction of spray from the accelerator pump nozzle. Sometimes they aren't aimed correctly from the factory. The stream should be aimed to go through the notch in the choke plate. Also, sometimes the accelerator pump actuation rod is a little too long, which causes gas to come out of the nozzle intermittantly while the bike's running. If that's happening, you can file a bit off the end of the rod to cure it.

 

+1

Replacing the butterfly with a CV was one of the very first mods to mine when I got it several years back. Well worth the effort - all my carb issues disappeared overnight. I believe the good doctor is correct in that '89 was the last year for the butterfly/compliance fittings.

I had an indy (who sold me the used CV) do the work so I can't help you with the list of parts etc.

 

I had a problem with accelerator pump that would spray ok on first twist and if I accelerated again in a short time it would hesitate,found check weight under nozzle did not seat properly ,so pulled nozzle and rapped lightly on weight and reinstalled accelerator nozzle and ok.Carb worked good and also fooled with pump due to excess travel until pump sprayed ,but wfo the throttle and it reacted like a cars 4 barrel ,but eventually switched to CV.Remember Harleys don't like the throttle snapped especially at lower RPM ,open just quickly roll it on.

 

Johnny, we have an adapter that is a press on , not rubber. This makes things a lot easier. Call me.
John