Tuning questions for the Stage 1 kit

Hi all, I'm new here. I installed the kit on my 03 Heritage using the 195 main and the 48 pilot as instructed. The engine would Idle perfect and ran great to about 2/3 throttle but lost a little from that point to WOT. Doing the WOT test and backing off slightly the engine would stumble then pick back up. Also, while coasting It would backfire out the exhaust, a little when I first back off the longer I coast the worse it would do it. So I dropped to the 190 main and 46 pilot and this helped. Idle is still great, just had to back out the EZ adjust screw a little farther. Now it feels strong at WOT with just a slight stumble then quick recovery when I close the throttle an 1/8th. However, the coasting backfire is still there and didn't really improve with the smaller jets. I'm running Vance and Hines Big Shot Longs, and the K & N Big sucker filter. Two things that I don't understand. First why would it be to rich with the jetting for stock filter and exhaust considering the mods I have. Second, why the backfire, this was never an issue before. BTW the jets I pulled out before the kit were 45 p and 185 m

Thanks

The exhaust system only has about 1k miles on them and still have the factory baffles and there were no issues with backfire before the kit. I did however check and re-torque the exhaust, and look for signs of leakage at the head but found nothing wrong. Also with the slight stumble coming off WOT do I need to try a 185 main?

Thanks

I have the factory spring I took out of it which is slightly longer than the one in the kit I could try if the 185 don't help. The V&H big shots have the crossover that they call the "power chamber" that helps scavenging. Also they are the long pipes that come out past the swing arm which I would think wouldn't be as bad about pulling the fresh air in like the short pipes will. I'm gonna try the 185 and retorque the exhaust and give an update.

while your playing you might through in a set of new SE gaskets retourqin woun't do much if the gasket is already bad

Ok, I tried the 185's they were too lean so It got me thinking it can't be the carb. I removed the exhaust only to find that it WAS leaking just not enough to hear. It had SE gaskets in it, I put the stock ones back because it looked to me like that soft taper would seal better. Put it back together, and no more backfire. The weird thing is I had no backfire before the kit and it had to be leaking then, I guess with a better metering of fuel things need to be right. With that issue gone I could concentrate on tuning. I ended up with a 48 P and 190 M. The throttle response is excellent now, mid range is great. Next week we'll see what the mileage is ridin' down to Thunder Beach.

Thanks for all the help