Hello community!

[Edit] meant to say this, but I’ve tried to search this issue every which way before posting. Every thread seems to be about the pilot jet pathway, and I simply need other possibilities that aren’t coming to mind. Hate to take this thing to the dealer 😤.

Here I am with my inaugural post, and it’s bittersweet. I’m excited that i have my first Harley, and kicking myself because I can’t ride it yet!

So, to the point. This bike is a 2003 XLH883. It starts quick and strong with the enricher out. However, as a I put it in, the bike really struggles. Only when the idle speed screw is halfway utilized will it run without choke and it still dies on occasion.

The Mods:
Not familiar with this bike, so forgive me. I know from the logo it has an Arlen Ness AC, and the pipes are just headers straight to the back. Are Harley’s good with that straight an exhaust setup? It’s loud, yea, but I’ve never heard it’s good for an engine to just run headers and that’s it.

The carb:
• 45 Pilot with 165 Main. No shims or anything like that.

• is it clean? It’s the cleanest carb you’ve ever seen. Every part of this carb (except for seals) has spent at least an hour+ in carb parts dip and carb spray. All passages have been cleaned with guitar string and air compressor.

• the diaphragms are both good, although I have a spare accelerator one on the way just to change it out.

• Fuel mixture screw: I’ve tried at 2.5 turns all the way to about 4 (which is way too much I know). Doesn’t seem to matter.

So, what are some other thoughts? Looking at the mods, could it be as simple as needing a 50/55 pilot jet to make up for the previous owner ripping off the ends of the mufflers?

Are there common places for extra air to get in and cause these issues? I can see from the AC that the filter is a bit bent where the bike leaned against a trailer on my haul home. I thought this may be the issue, but these air cleaners are so free flowing already I figured that wouldn’t be the culprit.

Many and all help is greatly appreciated!



Photo of the pipes

Photo of the air cleaner

 

just started doing this?
intake seals good?
no air inlet at carb throat blocked (holes around the venturi)
just into the carb and installed parts incorrectly?
mechanical check, aka compression
sat up awhile? corroded air passages which restricts air (bad mojo alum body and alky fuels)

 

i would bet that bike has cams in it, the adjustable pushrod tubes and tube adapters are what make me think that, make sure that your petcock is flowing well, then check for vacum leaks,,,,,intake gasket.manifold seals, vacum lines etc. make sure that you are setting your idle speed at 1000 rpm, sporties dont like to idle lower than that and some cams want 1100. make sure that you have no vacum leaks then report back.
m

 

thank you both for the replies!

my new air cleaner to replace the bent one comes in today. When I install I will be sure to check all the gaskets with a torch.

As as far as the Petcock, how do I create a vacuum to check it’s flow?

 

Have you ridden it previously and it run OK? Or did you buy it as a poor runner? How quickly are you pushing in the enricher? If the weather is cold it would take several miles of riding before I would do that, after that my engine is up to temperature and runs/idles just fine. It could take several minutes of running on the jiffy before getting warm enough to idle without the enricher.

 

Its a wacuum leak

 

the vac petcock does not take much to open. you could do it yourself or use a syringe in the hose. i have gutted mine and it operates like a manual one. that said, cracked hose from carb to voes/petcock is a common failure.

 

Hey guys! I didn't get to work on the bike much this week, but got a good bit done today, and I figured I owed you an update! My plans were to completely change all intake gaskets as well as replace the accelerator diaphram, Pilot jet, and add lollipops... however, I have a 4 month old, and the old lady works on Saturdays... So I got done what I could!

I ordered both a 50 and 54 Pilot (currently running a 45). I was going to run each and do a butt dyno, but Howie was rather fussy today, so I said to hell with it and stuck the 54 in there. Upon trying to get the intake manifold off... that was a no go. Unfortunately, I don't have a cuttoff tool to manually make the needed hex tool (sad fact as I am an account manager for Milwaukee Tool lol). However, I ordered the whole gasket set and was able to simply replace the carb to manifold rubber gasket... Let me tell you that was huge. Being my first harley, I didn't know the typical characteristics of that seal, but I can tell you the old had the carb floating in place, and the new one required the breather bolts to actually seat the carb into the gasket. Among all the work I did today, I would bet dollars to donuts that was the fix.

I also was able to move the fuel mixture screw from 4 turns back to about 2.75. As far as the idler goes, I think I'm at about two turns, which is a bit far for my typical taste for any bike, as I don't like using that to compensate for what could be more heinous inefficiencies. However, once the bike warmed up, it reved and idled very, very well. No rev hanging, no spitting, no popping.

As far as the lollipops, I would like some insight. I went to the home depot and fashioned baffles out of an eye screw. I used 1-1/4 washers to create the actual baffle. I was guessing my drag pipes were 2", but they are actually 1.75" wide. Will lollipops that are 1.25" in diameter be too large for these drag pipes? People mention worlds of difference with only an open eye-screw, so I am worried only leaving .5" of space around the baffle may be overkill. Would love some insight!

I also found some screaming eagle cans (fully open as well though) that I may add to the drag pipes after cutting them a bit... still cannot decide here.

Thanks again for all the ideas and insights! Would love to know more about what you think about the lollipops tho!

 

i run a tricked xl1200s and the 45 is what i run and it is actually borderline rich. i do not think the bigger jets will help. usually, the adjusting of the mix screw will tell you if you are ball park. a miss matched exh will be a bane, been down that road.
as far as the lollipops go, band-aide and will only offer a sweet spot range and outside of it, you could have issues. you just have to experiment till you are satisfied.

 

Make sure the gas cap is vented.
Scott