So bought a used 1997 Sportster 883.
Initially the only issues were idling and running a bit rich.
Then it go to the point the bike would stutter and want to die when above 3,000rpm and more than around 1/2 throttle.
Now it's puking oil out the breather and won't hold oil in the tank.
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Mods: aftermarket air cleaner. And what appears to be a stock exhaust
Things I've fixed. New plugs, new intake manifold gaskets (fixed leak). Changed main jets from a 190 to a 180 because they were set up that way because of the leak. I replaced the check valve ball and spring. Also when I popped the drain hose off barely any oil came out. But the tank does fill up about 2/5th the way when the bike is running.
Tried to tune it as best I could.
Absolutely no change. Spitting oil, shuttering even worse now. Fouling plugs.
I checked the ignition coil and I'm getting good spark. No matter what I do it wants to run rich.
​​​​​​Good compression on both cylinders. I can't tell if it's running hot because it won't hold oil in the tank for the temp gauge on the fill cap. But before it wasn't. This is only a problem that started a few days ago.
Carb has been cleaned, checked, and checked again.
The bike starts up and idles fine. No problems there. Initial throttle sounds good. But the bike won't go over 55 mph because as soon as I try to give it any amount of throttle beyond maybe 15% in 4th or 5th gear it sputters.
I checked timing and it's good.
At this point I'm out of ideas on what to check. I really would rather not take it to the stealership and would really like to fix this myself but at this point I'm kind of at my wit's end and just want to ride!
I linked a video from earlier today when I tried to test it after I thought I fixed it.

https://youtu.be/dC4lvW2JhB0?si=HKw92tSkxE9icKFm

Also it was dripping out of the breather filter after I got back into the garage after riding for around 5 minutes. 🤷

At this point I just need to know if I'm missing something.

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Welcome. Let's try to sort this out a bit. That's a lot of info to absorb at once.

180 mainjet is generally way too big for an 883. Try a 170 (or 165) mainjet. What pilot jet do you have? Are you sure it's really an 883 and not bored out? Sounds like the problems above 3000 are because of the 180 jet. You're drowning the motor. Fixing your vacuum leak changed the motor's needs, so lean up the main jet.

Oil level. You need to check when warm, right after you stop. If not up at mid between the marks, add some oil. If it drains down into the crankcase when shut down that's okay, it happens to all Sportsters to some extent. If it's leaking somewhere externally, that's not okay. When you start the motor the oil will get pumped back into the tank, that's how it works. If there is a lot of oil drained down, you need to give some time for it to get pumped back into the tank, so maybe that was what contributed to your puking. Let it warm up a bit and ride gently until the bike is warm, don't ride off at WOT on a cold motor.

Oil puking from the breathers. Define puking? How much. Most Sportsters do pass some oil from the breathers, if it's a lot, you can easily change the umbrella valves in the rocker covers and see if that fixes it. Or, install an external breather kit, they are very common. DK, our sponsor has an extensive product line.

What check ball and spring did you change? If the oil isn't all over the ground, it's still in the motor. The motor takes 2.5 quarts, how much have you put in?

Sounds like most your problems are fairly common and easily solved, or at least you can narrow down the issues.

Good luck!

John

 

Appreciate the quick response. The only issue is I couldn't find anything under a 180. No one appears to sell a 175 jet or 170 by itself. The needle is adjustable and it was running rich so I adjusted 2 notches lean. Not sure if the carb already has a jet kit or not. And also I thought 175 was stock?

Is there another drain point? Because the only one I could find is the rear tube. And when I pulled that today barely anything came out. It drizzled for about 2 minutes and then went dry.
And as far as how much puking it was coating the entire side of the bike in oil. Left a decent puddle once I stopped.
Also I thought the oil was supposed to stay in the tank when the bike is off.

 

Here, you go. You can get jets and a fixed needle (Velocity needle is what I use) from these guys, they will ship to Texas. It sounds like you might have a Dynojet kit with the adjustable needle. If so, you should buy a new emulsion tube and jets and needle from CV Performance. The threads on the Dynojet emulsion tube and jets are different than the stock Keihin jets.
https://cv-performance.com/

Here's another good place to buy jets:
https://www.jetsrus.com/

"Also I thought the oil was supposed to stay in the tank when the bike is off." I think it is, but it doesn't. That's just how it is. Mine barely drains back, but every Sportster seems to be different.

My 1991 has a different oil drain than a 1997. Google "Sportsterpedia" and it is a fantastic source of information. It will show your oil lines and drain system.

Do you have 2.5 quarts in the system? How fast does it drain back into the motor? Let's make sure you have enough oil to begin with.

Good luck, success is near.

John

 

Did you add oil to the tank before allowing the motor to warm up?
Like mentioned earlier sometimes the oil will sump in the bottom of the motor, which is something that happens to many Sportsters but is not harmful.
However if you add oil to the tank before running the motor it will pump the excess oil back into the tank then start puking oil.