Full Akro Observations/Questions

I am noticing a couple things after I got a full-system Akrapovic exhaust done on a 2021 V4.

1. I have been riding it everyday at street speeds (<100 kmph) to get used to the feel/power. However, every time I park it after a ride, I get a very strong "fresh" gasoline smell. I mean I used to get a smell with the stock exhaust too, but that smell was a little "used"/burnt gasoline smell if you know what I mean. The smell with this exhaust is too fresh... Almost AS IF there was a leak or something. (Not saying that there is actually a leak).

2. The power delivery is very "slow" on the lower RPMs compared to stock exhaust. I guess this is just because of the new mapping? Once again, this is from my memories of riding with the stock exhaust when the bike (for the same riding mode) had quite a bit of punch right from the get go. That punch appears to not be there anymore.

Just FYI, a very experienced mechanic has done the installation for me. And also got the ECU mapped/flashed from a Ducati dealer.

I am not overtly concerned or anything. Just curious if others have noticed something similar.

All normal.

Keep riding.

Normally the tank breather vents to the EVAP canister, which is removed during the install or can be removed during the install. Which if its removed, the tank vents to the atmosphere. Since the gas tanks is sitting on top of a very hot engine there is a lot of vapor being generated. Since its being vented directly now, you're going to smell it.

After I installed my full system, I noticed under hard braking I was getting a fuel puddle underneath the bike, coming from the overflow line. I came across another forum post whereas someone was saying there was a steel ball in the gas cap assembly to function as a check valve, which was removed somewhere in the production run, due to the bikes vapor locking when the EVAP canister was installed. I added it back but haven't tested it yet to see if it effects the bike dripping gas under hard braking.

My bike, a 2021 doesn't have the mesh in the center nor the silver disk with the spring on the left. I added the ball back, which is a 4.5mm stainless steel bearing.

Removing the evap can will cause the smell as well.

bp_SFV4 said:

Normally the tank breather vents to the EVAP canister, which is removed during the install or can be removed during the install. Which if its removed, the tank vents to the atmosphere. Since the gas tanks is sitting on top of a very hot engine there is a lot of vapor being generated. Since its being vented directly now, you're going to smell it.

After I installed my full system, I noticed under hard braking I was getting a fuel puddle underneath the bike, coming from the overflow line. I came across another forum post whereas someone was saying there was a steel ball in the gas cap assembly to function as a check valve, which was removed somewhere in the production run, due to the bikes vapor locking when the EVAP canister was installed. I added it back but haven't tested it yet to see if it effects the bike dripping gas under hard braking.

My bike, a 2021 doesn't have the mesh in the center nor the silver disk with the spring on the left. I added the ball back, which is a 4.5mm stainless steel bearing.

View attachment 42090

Click to expand...

Link to that thread?

craig bush said:

Link to that thread?

Click to expand...

https://ducatimodified.com/threads/22-v4-fuel-leak-on-track.206/

I posted on the DM forum but will here to. Adding the 4.5mm check ball back to the gas cap assembly stop by fuel dripping on hard braking problem.

A slight update...

After my post I went to the garage and opened my freshly filled gas tank. I suppose it was still hot, and the gas came bubbling up the filler neck and all over the tank. Slight pucker factor. I calmly wheeled it out of the garage and rinsed it with copious amounts of water. So, don't open your gas cap if you just filled it and your bike is still warm. I don't know if this is related to the check ball or not. Just prior to getting home, I had filled it up to the very bottom of the filler neck to really test if I could get it to spill while braking. I couldn't, but it bubbling out of the filler neck surprised me. Probably just because the bike was still hot. No vapor locking problems like when the EVAP canister is installed. It was about 85F here today, so warm but not super hot.