Catch Can & Check Ball Nonsense

bp_SFV4 said:

If you have a 2018, all of the valving/check ball nonsense is still installed in the gas cap breather assembly unless you had the recall done. Even if you replaced the stock cap the breather assembly is reused.

None of these parts except for the red plastic piece are present on my 2021.

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Recall was done when it came out and not long after, I replaced the entire gas cap assembly with a different one. I did not reuse any of the breather assembly. Still never any leakage except when I accidentally overfilled once or twice.

What gas cap do you have then? The bottom half didn't get re-used?

MaverickiB said:

Recall was done when it came out and not long after, I replaced the entire gas cap assembly with a different one. I did not reuse any of the breather assembly. Still never any leakage except when I accidentally overfilled once or twice.

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What gas cap do you have? All the ones I see re-use the lower half.

The Lightec gas caps are pretty much one the only ones that don't use any of the oem pieces. I don't know why people install a billet gas cap over on top of the junk plastic lower half it doesn't even vent properly.

Dont overthink it, catch cans have been on racing bike since day dot. People use all kinds of bottles, basically it's whatever you can find that fits, run hoses. For the occasional track day I wouldn't bother, and a few drops of gas on the ground isn't a big deal, maybe it's being overfilled?

I will look into the Lightec, thank you!

Searching the forums here and on Google using "ducati panigale gas tank overflow breather" there were dudes on the xx99 bikes having similar problems. With the V4 I think its a different problem with the same symptom, fuel dribbles.

From the 2018 recall.



From a 2019 recall. Both of these recalls were meant to address fuel spraying from the gas cap when opening it. Which is a pressure problem from an inadequate EVAP system. I suspect the design of the V4 fuel tank would allow forward sloshing fuel under hard braking to enter the overflow and/or breather tubes but when the tank was designed, there were all of the implements pictured in the 2018 recall snapshot present. All of those implements were removed without addressing the internal design of the tank, cause profit.

Paul G said:

Dont overthink it, catch cans have been on racing bike since day dot. People use all kinds of bottles, basically it's whatever you can find that fits, run hoses. For the occasional track day I wouldn't bother, and a few drops of gas on the ground isn't a big deal, maybe it's being overfilled?

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Not being overfilled and I don't want to get flagged. LOL

I got a fuel resistant catch bottle to install, but I'd rather address the problem at the source. I think its all related to mitigating tank pressure because Ducati's EVAP solution sucks. Well, it is insufficient for the amount of heat which gets pumped into the V4's gas tank.

I have noticed after rides with aggressive braking the lower faring ports rearward have dried gas. It shouldn't be happening. There's no reason I can think of that if you accelerate to 40 MPH and make a max effort stop there should be drips of gas from the overflow line, regardless of tank volume. On a track there'd be way more high effort stops from greater speeds to suitable turn in speeds. The impetus of this thread was a track rider on another forum getting flagged.

The plastic square catch similar to the one Yoon Racing uses doesn't fit so well under street fairings. It would be fine if it were round.

I found this...for a whopping $1.93 which is an 8oz aluminum bottle with a black plastic screw on top. 2.1" in diameter, 5.6" in overall height.

Is this a coolant overflow bottle?


Couldn’t you use something similar as a catch can on the other side?

I'd prefer to keep it under the fairings but that does look like a generic overflow bottle. I saw a few online but they seem to be overpriced for a random plastic jug.