So I recently installed new 1 3/4 drag pipes. The bike is now backfiring and popping on deceleration. My first thought was duh... the gaskets are leaking. So I replaced them. Twice. Absolutely no improvement one way or the other. Today I ventured a guess that maybe the new pipes are screwed up or something and I reinstalled my old two inch drags, and now they are doing the same thing. So I just now put the 1 3/4 drags back on, went for a quick ride and yep, still popping and backfiring. Ideas please?

 

It ran fine before the swap? Maybe retrace your steps, something get bumped, moved, disconnected? What a drag to go back to square one and still have the same problem. Sorry coulnd'nt be more help. Good luck.

 

I thought that was normal, my pipe's really pop and reverberate, on the de-cel without the baffles in. But with them in, the de-cell is very smooth. The baffles are strait through, so they don't restrict anything, but they work. Strange your old pipes did not do this before, what has changed since you swapped the pipes? did you put the torque cones back in?

 

LOL, never mind. Problem fixed. I don't know how I missed this but I guess I was just stupid for assuming the brand new torque cones were fine because they were..... brand new. I replaced the gaskets and never even looked at the pipe itself. Heres a picture and you can see plain as day the massive exhaust leak between the pipe and torque cones. I put my old cones back in and its all good to go. Damn, I have been Chinese'd again. But Its all better.

Thanks for the replies.

 

Mine did that when drag pipes were added by the previous owner. When I got it, it was popping on decel. I changed out the 42 pilot jet to a 45, and the main jet to 180. No more popping on decel, and don't need the enrichner after starting. I don't understand however, why yours was OK with the old set of 2" drags.

 

When I put the new pipes on I also installed brand new torque cones. It started popping for the first time ever. Then when I put the old pipes back on as a test, I also used the new torque cones. I figure they must be warped, the wrong size, junk or something. Now I have my old torque cones in the new drag pipes and its sealing up fine. I didn't make it to the end of the street and I could tell a difference. I jammed two towels in the end of the pipes at idle and no ticks or pops either. So all is good. My jetting never changed as I am just switching one set of drag pipes for another. I run 48/190 jets and have been for ages. It has never popped on decel ever, until the new drag pipes went on Friday.

 

Glad you got it figured out. How do the new 1-3/4" drag pipes sound. That is what I am running on mine. I do love the sound. I played around with different things on mine. I first tried lollipops, and like you I did not like the tinny sound. I then took a piece of 1/2 wide strap steel an 1/8" thick, and bent it 90 deg. on one end about a 1/2" long, and about 6" long on the rest. I bolted that in where the lollipop had been, but it did move it up the pipe the 6". That took out the tinny sound, but also took out the rap on decel. It also quieted it down just a smidge. I have run it that way for quite a while now, and like it just fine. I do not know if mine has torque cones in it or not, as the pipes were on the bike when I got it three years ago. It did not seem to make much difference when I added the lollipops, so maybe it does have cones.

 

Honestly, I can tell almost no difference at all between the 2" and the 1 3/4 as far as sound. I was expecting the 2 inchers too have a much deeper tone, but they just don't. Maybe its because the torque cones reduce the exhaust stream to the same size exiting the head no matter what pipe is on..... I have no idea. I just know they sound very similar. I really like the look of the 1 3/4 pipes as well. What surprised me is yesterday both the guys I met up with knew right away I had different pipes just by looking, so visually it must be pretty noticeable because I didn't mention to either one I just swapped pipes. Of course maybe the ridiculous popping was the give away. Like you, I will probably leave the pipes as they are for as long as they last. I imagine the next owner will be putting on the next set of pipes, not me.