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Well, if it is any consolation, I think you are likely on the right track. Thinking that bike sitting for extended time would most likely be fuel related issue with performance, so complete what you started and see if problems persist.
 

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A couple of things haven't been mentioned yet:

You can check the accelerator pump function just by twisting the throttle quickly while looking into the carb: You should clearly see fuel squirting into the carb from the nozzle (if there is fuel in the float bowl).

If you haven't done it yet, the fuel/air mixture may need to be adjusted, especially if the carb was disassembled. If it's adjusted too lean, it can have the same symptoms as a partially clogged slow jet: spitting and sputtering when you try to rev the engine. Just make sure to turn the screw all the way in first and count the turns so you won't turn it out so far that it falls out (no more than 4-5 full turns). There are plenty of sources online for how to adjust it, but you don't need it to be perfect to find out quickly if that's the problem.
 

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Read the whole post, about everything mentioned.
 
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Hello new to forum and have already introduced myself.

I recently procured a 2003 100 year anniversary dyna low rider.

Our local Harley service shop was set back as the main mechanic was in an accident.
So any service is put on a back list and the time they are saying once the bike does get there is way way out.

Anyway, with that said. Bike has been sitting for a while when I bought it. It has 10K miles. 1st thing I did was buy new tires and inquire about them going through it. It does start but had trouble idling.

Decided I would attempt any service on it.
I changed all three oils, put in new plugs.
Siphoned out the old gas that was in tank.
But, when buying it last owner and I did start it up and cycled old gas through the bike.

Me and a trusted mechanic friend went through the carb and cleaned it thoroughly, adjusted the throttle cables. Got a lot of gunk out of the carb.

We were able to get it so on the first click of the ignition the bike would start up and idle just right.

So I took it out for a quick spin, and it is sputtering so bad, I barely went 3 blocks and was lucky to get it back to my garage.
Still fires up and idles just fine, but when I give it any throttle sitting it seems to be starving for fuel... like at higher rpms

If I feather it I can get it to do a little better as the rpms climb.

Am trying right now to buy a service manual but in the mean time, I am thinking about Siphoning the gas out once again, tear into the pet-cock valve checking for any thing in there and searching for where the fuel filter is.

Any other suggestions on where to go from here would be greatly appreciated,
Cheers Joe
Didn’t see it in other replies, but my Sporty was doing similar things with the spitting and all, and doing a little research it looks like it might be a problem with the ignition module. Starts and idles fine, but spits intermittently while riding. Not a problem with gas or carb. Something to consider. Good luck.
 

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2011 Harley-Davidson FLHX Street Glide (Ginger); 1992 FXSTC Softail (Stitch)
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Nobody has mentioned intake leaks (common) as of yet - unless I missed it.
Was about to mention just that.

One time when I pulled the entire carb assembly off my Evo to change out the choke (er... enrichment) cable, I didn't get the rubber gasket between the intake and the carb assembly just right so it was leaking air. It idled okay but bogged down on acceleration. To remedy it, I simply had to pull it back off and reseat it with the gasket properly in place.

Easy fix to a rookie mistake.
 
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All over the place with diagnostics for this OP's bike ! I haven't chimed in yet because they're so many other knowledge sources looking at this thread ! Waiting to see where it goes before I open my mouth !
 

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Buy a carb rebuild kit like 2003 Harley-Davidson Dyna Low Rider - FXDL Carburetor Jets - Dennis Kirk and rebuild the card. The holes in the jets are tiny and can get clogged easily. There are a number of YouTube videos to guide you. Defiantly soak the carb over night. In the future always use a gas additive, I recommend Seafoam to keep the carb clean and varnish free,
 

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All over the place with diagnostics for this OP's bike ! I haven't chimed in yet because they're so many other knowledge sources looking at this thread ! Waiting to see where it goes before I open my mouth !
I think I posted this to the wrong thread. I've already chimed into this thread earlier.
 
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Discussion Starter · #37 ·
When you removed the main jet did the needle jet fall out at the same time ??? The symptom you described aligns with an upside down needle jet ! You can check this without taking the carb back apart. Remove the AC and look into the carb throat where the needle passes thru the jet. The top of the jet should appear concave not flat. That jet fits in either direction and the symptom you describe indicates the jet is installed upside down ! Maybe

Ok finally have some time here Schmidty, and definitely the top of the needle jet seems flat and not concaved.....

Think I should remove the carb and flip it over?
 

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Discussion Starter · #38 ·
Well, upon further inspection, I did buy another carb...
Took it out to look at it and it appears to be in the same position as the needle jet on the bike.

I did start it up to spray starting fluid on intake seals, no change in operation.

But, when I gave her throttle it seemed to struggle most when I opened it up, could it be accelerator pump?

Would it be alright to take that loose from the carb and clean it where it is?
 

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Look in the carb throat and give the throttle a twist. You'll see it if it's working. Starting to wonder if you need to start at the beginning: basics - fuel (14.7:1 stoichiometric)/spark/compression/valve timing. I need to read this thread again, see where you have come, and where it is going.
 

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Well, upon further inspection, I did buy another carb...
Took it out to look at it and it appears to be in the same position as the needle jet on the bike.

I did start it up to spray starting fluid on intake seals, no change in operation.

But, when I gave her throttle it seemed to struggle most when I opened it up, could it be accelerator pump?

Would it be alright to take that loose from the carb and clean it where it is?
YES!
I said that last week.
Rubber cracks over time.
If it is bad it will not pump fuel from the bowl when you twist the throttle.
It is a cheap part to replace , any HD dealer will have them in stock.
 
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