Spoorster gas tank question

[ElvisQuanbeck]

So this is probably gonna sound like a dumb question but I'm gonna ask it anyway. I own a 2004 Sportter 883xlc, if i remove the fuel lines and turn on the petcock to either main or reserve it should have fuel pouring out of the petcock at that point correct?

Here's where I'm at. Thought I had an issue with the carburetor being clogged as it would only start and run while blasting it with carb starting fluid and as soon as I stop spraying it the bike dies. Dropped the bowl on the carb and cleaned it a bit with air and cleaner, put it back on and tried firing it up. Had the exact same thing happen. Then I realized something, when I had pulled my gas tank to remove my carb from the manifold, I noticed the petcock was still on and no gas was leaking. I unplugged the fuel lines and checked again on both main and reserve. No fuel coming out of the petcock.

So, is there some sort of vacuum mechanism inside the petcock that I'm unaware of which keeps it from losing fuel OR do I more than likely just have something in my tank keeping the gas from flowing out of it???

[JBinNC]

You got it. If it's the stock petcock, it is vacuum operated, and fuel won't flow unless it gets manifold vacuum through the small vacuum line. That vacuum line also runs the VOES switch. The petcock and the switch can develop vacuum leaks (diaphragm goes bad) or the vacuum lines themselves may leak. Your bike is at that age.

You can replace the factory petcock with a standard petcock to eliminate the possibility of a vacuum leak shutting off your fuel supply. But do remember to turn off the fuel when you park the bike.

Jim

[ElvisQuanbeck]

You got it. If it's the stock petcock, it is vacuum operated, and fuel won't flow unless it gets manifold vacuum through the small vacuum line. That vacuum line also runs the VOES switch. The petcock and the switch can develop vacuum leaks (diaphragm goes bad) or the vacuum lines themselves may leak. Your bike is at that age.

You can replace the factory petcock with a standard petcock to eliminate the possibility of a vacuum leak shutting off your fuel supply. But do remember to turn off the fuel when you park the bike.

Jim

SO it sounds like, with the information I gave for my problem and you gave with solutions, is that I swap out my petcock so I don't have to concern myself with the vacuum sensor hullabaloo or I find the possible leak in my lines that are causing my problem to begin with?

If that's the case it sounds to me like swapping lines might be cheaper, faster, and easier than ordering a new petcock. That being said, is there anything else that might come to your mind as far as why the bike is behaving in this manner?
Like I said, I can start it and run it with carb starting fluid but as soon as I stop spraying it in my carb the bike dies.

Again, I have a 2004 sportster 883xlc and I own a clymer manual that I bought off Lowbrow. I'm only willing to repeat myself so many times in this thread so help me god if someone @'s me later. Thanks again for the help @JBinNC Jim.

[rockman96]

Check https://www.carlsalter.com/harley-service-manuals.asp for a factory service manual... They may or may not have your specific one, but they have a huge selection, free to download. Clymer manuals leave a lot to be desired.

[ElvisQuanbeck]

Check https://www.carlsalter.com/harley-service-manuals.asp for a factory service manual... They may or may not have your specific one, but they have a huge selection, free to download. Clymer manuals leave a lot to be desired.

I'll have to check that out when I have time to do a deep dive. I didn't see any hyperlinks for 2004 sportster.

I'm leaning towards faulty petcock at this point. I drained the fuel from my tank and pulled out the petcock. The filter attached to it that runs up into the fuel tank didn't have any dirt or tears in it. I disassembled the petcock and took a pretty close look at the vacuum diaphragm that was inside of it, other than being close to 20 years old it didn't look horrendous. The backplate of the petcock that helps house the diaphragm did look like it had a seal starting pop out from the center of it though. Is this enogh to fuck with it? I don't know, maybe, but like I said it's almost 20 yrs old and goes along with how my problem started in the first place.

When the bike stopped working I had just pulled out of the driveway and I thought it was running out of gas so I tried to flip it from main to reserve and it died. It had plenty of gas at the time so we tried jumping it thinking it was battery.
Later I checked the starting system, then I cleaned the carb, and now I'm onto the petcock. It's gotta be the fucking petcock.

So unless someone has the best reference ever for a vacuum petcock, looks like I'll be hitting up lowbrow for a few things this week.

[rockman96]

It's gotta be the fucking petcock.

Sure sounds like it. If you want to prove it before throwing bucks at it, rig up an alternate fuel source (can, bottle, etc) to gravity feed the carb and see if it runs.

[TriNortchopz]

...So unless someone has the best reference ever for a vacuum petcock, looks like I'll be hitting up lowbrow for a few things this week.

"I heard if you take the petcock apart and move the spring to the other side, it will act like a normal ."

"Yeah you just reverse the spring so it stays open, and you can leave the plastic disc in there to hold the diaphragm in place."

"I've never done it, but a friend said his wrench turned the spring and the diaphragm around..."

"You used to be able to just move the spring inside the petcock to the opposite side to bypass the "vacuum" function. The diaphram on the petcock ..."

Price: zero bucks

https://www.google.com/search?client...s=heirloom-srp..

[Dragstews]

Petcock Valve Body Vacuum Bypass Kit .... Price:$25.24

VT No 35-0426

[ExplodingCoffinEmporium]

Did you pull and clean the Jets when you cleaned your carb or just kind of carb clean spray it out? Gas is shitty and I clean the jets with fine wire yearly at the beginning of the season on my wife’s 06’ XL. Also did you check the condition of the vacuum lines, any breaks etc?
The vacuum petcock and VOES system works great as long as it maintained. I’ve cleaned up the petcock a few times on the 06’ including taking apart the diagphram and never had any trouble, but maybe I’m just lucky.

[ElvisQuanbeck]

First off, HOLY SHIT!! Vacuum petcocks are fucking stupid. I get it, technology evolves and shit like that. But wow, this seems more like a way to charge more for a part than actually fixing a previous issue.

Anyways, I've gone ahead and ordered one of those bypass valves, but until that shows up I'll probably try flipping around that spring to see if I can actually fix it for free. It seems like if I want to replace the whole vacuum petcock itself then I'm either gonna spend $40 on ebay for a used one or drop the $200 or so on a fucking Golan or Pingel because those are the only fucking options for vacuum petcocks. AWESOME.

As far as cleaning out the whole carb instead of just the bowl, no I did not. But like I mentioned earlier in this thread, everything starts and runs fine if I'm blasting carb starting fluid but as soon as I stop spraying that shit the bike dies. That seems like a pretty good indication that the carb isn't getting gas in the first place. Plus when all this shit started it acted like it had ran out of gas but had plenty in it.

[ExplodingCoffinEmporium]

As far as cleaning out the whole carb instead of just the bowl, no I did not. But like I mentioned earlier in this thread, everything starts and runs fine if I'm blasting carb starting fluid but as soon as I stop spraying that shit the bike dies. That seems like a pretty good indication that the carb isn't getting gas in the first place. Plus when all this shit started it acted like it had ran out of gas but had plenty in it.

If your jets are gummed up it will still run on starting fluid as your bypassing the carb. Are you getting a good spray when you manually twist the throttle? Did you check your vacuum lines for cracks/wear etc? I’m only pointing this out because I’ve seen this exact issue occur because of clogged jets, bad floats, or cracked vacuum lines numerous times.

[ElvisQuanbeck]

No visible cracks or holes in the vacuum line. When I twist the throttle I do see gas coming out of the jet. And when I cleaned out the carb bowl I did remove the couple jets I could access from there and wire cleaned them.

I did try flipping the spring around in the petcock in order to bypass the diaphragm, plugged the vacuum line from the carb back into the petcock, and it was doing the same thing. Only running with carb spray. That being said, gas was able to flow out of the petcock properly once I flipped the spring around, its the vacuum hose part I'm not sure I did correct. Was I supposed to plug the hose back into the petcock or put a plug in the line?

I'm probably going to walk over to Autozone tomorrow and get a plug to see if that's the ticket or not. Like I said earlier I also ordered one of those bypass valves to see if that works.

[TriNortchopz]

Did you pull and clean the Jets when you cleaned your carb or just kind of carb clean spray it out?...

Dropped the bowl on the carb and cleaned it a bit with air and cleaner, put it back on and tried firing it up....As far as cleaning out the whole carb instead of just the bowl, no I did not..."

If your jets are gummed up it will still run on starting fluid as your bypassing the carb.

Clean your carb, completely.

Harley CV Carburetor Tuning Issues & Troubleshooting
"...If troubleshooting a 2004-2006 model be sure to check the Diagnostic Trouble Codes (DTC) first to troubleshoot any sensor issues..."

https://cv-performance.com/harley-cv-carburetor-tuning-issues

[ElvisQuanbeck]

Rebuild the carb is my plan after i retry this vacuum thing. Went ahead and ordered a rebuild kit cause there's a high chance it might just be a dirty carb over a petcock failure this whole time. Just goes to figure, I was thinking that I should probably give it a clean since I hadn't after purchasing it almost 2 years ago and then of course all this shit started up.

[ElvisQuanbeck]

Juuuuuust sitting here on my ass waiting for a rebuild kit...