Don’t Blow It: Sportster Exploding Oil Tank

PLEASE – Tell your Sportster owners during the videos – DO NOT OVER FILL THE OIL TANK.

Note from Hogger Kelly:

Being my first HD, I ordered your Sportster DVD’s, watched, and changed my oil – when the engine was cold. I filled my oil to the top of the dipstick cold and, due to the fact that part of the oil drains back into the engine when cold, I overfilled my oil tank causing it to pressurize and rupture – twice!! Those PLASTIC tanks are $250 each!!! After oil tank #3 and a LOT of asking around, I isolated the issue and have not had a problem since. Always check and change your oil when the engine is hot, or you risk exploding your oil tank. Just Google “Sportster exploding oil tank” and you will see I am not the only one that has had this issue. Thanks, for the videos – I have learned a great deal.

I checked the internet and it looks as if several Sportster owners have had this happen to them as well. A guy in OKC, OK who previously was a maintenance shop manager for a local HD dealer and opened his own shop figured it out – but would not give me the answer until I let him put the THIRD oil tank on. (The original one that came with the bike, the one I put on, and the one he put on) I try to do as much work on my own bike as I can, but this is my first HD. Your videos have been very helpful to me in that regard. Both times when it blew, it was VERY loud and explosive. The rupture could be heard over the sound of the motor – even though I was running at high RPM down the highway. I wasn’t racing, just going about 70 MPH on the interstate both times. On the internet I saw several mentions from other HD owners that said their dipsticks had “shot out of the oil tank and spewed oil everywhere”. But the newer Sportster’s “turn and lock” into place; preventing their removal without twisting and unlocking them. The Sportster oil tanks are a two piece design and epoxied together at the top. Both times it separated at the seam where the epoxy was applied with a loud “POP”.
You are certainly welcome to post my information on your website

Kelly S., 2004 1200 Custom.

The way Bob mentions on the video: “The oil that we’re draining out of this is also still hot from when we did our charging system check. You want to try and drain your fluids when they’re warm. It holds up any debris, anything like that in suspension in the hot fluids.”…

We’ve used three full quarts of oil for this service—four ounces in the filter, the other two quarts and twenty-eight ounces will go in the tank. I like to check this once the bike is back on the ground and has been restarted after the service. I don’t like to overfill these motorcycles,but I do like to run as much engine oil in them as possible. The oil is what carries the heat away from the engine and allows the air-cooled engine to cool. With the two quarts and twenty-eight ounces back into the tank, this oil dipstick again is an O-ring sealed surface. Inspect the O-ring, make sure it’s in good condition. If it’s not, replace it. I’m going to reinstall the dip- stick cap. It’ll only go one way. Half a turn; pop it in the tank. The oil is completely changed.”

Bob during Final Safety Check After Service:
Again, you don’t want to fill the oil to over-capacity, but it is an air-cooled engine and it depends on as much oil as it can hold to dissipate heat. I’ll check oil level one more time. This is what makes capacities critical. You should consult the service manual for the exact capacity for your model. The oil reads correctly on the dipstick. I’ll reinstall it.

Related Videos:
Fluid Service
Safety Check
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6 Responses to “Don’t Blow It: Sportster Exploding Oil Tank”
  1. Wayne Pike
    Wayne Pike

    My 2012xl1200c has oil blowing out oil tank top oil level stays over full have even decreased oil level still doing it have been told crank case vent is stopped up not letting oil flow like it should

  2. diamond

    I blew out two oil tanks in the last couple of weeks on my 06 883 Sportster. Traced it back to a little aftermarket air filter I put on. The bolts that came with it were hollow as they were supposed to be but the wrong threads. Not thinking and in a rush I went to the local TSC and grabbed two bolts with the right threads and length an installed them. Didn’t realize those bolts were to let the engine breath. Just figured they were mounting bolts. Lesson learned, I put the old air cleaner back on. Will replace that tank one last time and get rid of that little aftermarket air filter.

  3. bschenher

    I have been curious about something for awhile relative to checking oil on my XL1200C. When you check the oil level, using the dipstick, should it be inserted and turned or just inserted to the point prior to being able to turn? Seems to be about a 1/4″ and maybe 8 oz difference. I have never heard anyone explain the procedure to this detail and haven’t found anything in a manual.