I put on the VH straight shots immediately after buying my new 17 Slim. I love the sound, especially at idle and the burbles on deceleration. However, it is popping (more like a backfire sound) quite badly on upshifts as I roll off and squeeze the clutch, especially 1-2 and 2-3 gear shifts. The dealer did not say anything about getting a tune when they sold me the pipes, so I'm assuming it is not necessary or that I'm doing anything bad for the engine. If it's just a personal preference for the sound, I'm fine with it. Can anyone confirm that it's not messing up the fueling or anything like that? Thanks.

 

It's not good, get it tuned.

 

Decel pop itself will not harm anything, but it’s usually a sign that you are running lean. Having the bike tuned should help, provided the timer knows what they are doing.

I have a FP3 tuner, and there is an easy adjustment for decel pop for every map.

 

A lean condition on decel has no ill effects. It can be fixed easily by adding more fuel and spark on the decel portion of the fuel table if it annoys you. If you don't mind it, leave it alone.

 

Your bike is running lean, get a tuner and tune it...

 

Yes.
And your bike will run better and cooler. Win-win situation.

 

Surprised you're not noticing any additional heat coming off the rear exhaust manifold area. I had V&H Big Radius on my Slim when I first bought and I had to richen the crap out of it.

 

Guys, it's on decel. The rest of the tune may be perfect. Decel doesn't generate heat!

 

We/I understand. Our bikes are lean from the factory and making changes to air flow without adding fuel will make the bike even more lean. OP did exactly that and needs to tune the bike. A tuned bike will run cooler and not have the decel pop he is experiencing.

 

I'm pretty sure he was joking lol