Popping on deceleration

[Metalefty]

'15 300, Stock motor and exhaust. Last couple of rides I've noticed some popping on deceleration and by popping I mean ignition firing way to much on decel. I did a search but the replies where all over the place. One reply said to change to a one size richer pilot, so I did and no difference. My carb settings at 5000ft. are,
main-165
pilot-35
needle-N2ZJ- 2 from top
This is also how the set up is on the Beta jet chart.
Amsoil dominator at 50/1
Plug looks normal.
I've changed the needle clip in all positions, no change, the air screw and idle in all positions, no change, throttle cable adjustment, no change. There is one thing that made a little difference but not a total fix. I adjusted the idle screw all the way out so that it wasn't touching the slide at all and it was stalling, then when I rode it the popping seemed to go away on decel down to about 3000rpm's then pop below that, but once I set the idle correct again I was back to square one.
This pop is annoying because it's not just a sound, it's also pushing the bike a little during braking. I feel like I'm missing something easy, anybody got any ideas?

[Enmerdeur]

The only difference on my settings is I have a 162 main. I ride at your same elevation.

What octane fuel are you running?

Does this happen all the time or just after coming down from a WOT run?

More than likely it has to do with higher compression head that the 2015 has although I have an S3 on mine it has only done what you say occasionally so I put that down to fuel inconsistency. My compression reads 150. Stock was around 130. I find Chevron has the most consistent pump fuel in our area.

[Calgarytrev]

I run at 3500ft and run 165 main and 38 pilot and I'm on the 4th clip on same bike(300 race) if I lean out the needle the bike runs like crap but as soon as I ritchen it up it's much smoother across the 1/4 to 3/4 throttle. You can tell it runs rich but is much better to ride this way. I'm going to try the jd needle and see if that makes any difference(red needle). Do you have a sound clip of what it's doing? I find I can get a lot off of just listening to the bike

[Metalefty]

I don't have a sound clip yet, but if I still have trouble i'll provide one. This happens from deceleration at any rpm. Octane is 91. The bike didn't do this for the first several rides and seems to have gotten worse the last couple of rides. Fuel and ratios haven't changed. Air boots are tight and the four bolts holding the intake are tight. I ran out of time the other night working on the bike so maybe today I will try to find a leak around the running engine with carb cleaner to see if rpm's rise. If nothing then it will be another total carb teardown and cleaning.

[Balkan boy]

Let me tell you how I learned to stop worrying and love the decel-pop.
(Well, I don't love it, but I'm not worrying about it anymore.)

I started to get deceleration popping around 50h. It was happening when closing the throttle from WOT, so I was slightly worried because the bike ran perfectly to that point. This is on a 4T, so I checked the valves. Exhaust valves were in spec and one intake was adjusted, but the popping continued. Then I developed a theory that I have air leak in the system so I sealed the the header and exhaust connection with copper paste. Bike didn't like this at all and spewed it all out. Next I started fiddling with the fuel mixture. I've richen it and the popping decreased, but bike didn't run very well. I've experimented with different octane petrol, altitude and temperature, but the popping always returned. I've even tried different amounts of oil on the air filter.
I was ready to disassemble the carb (witch I didn't, on good advice) when I returned the fuel-screw to somewhere like stock setting, put new tires on and just rode the bloody thing. This bike is truly amazing and works under every condition. I don't worry about popping anymore and I even think it's gone. Ambient temperature also dropped by 15-20C and bike is loving it. I've also read that all real racing engines pop on deceleration.

*I've recently blocked the crankcase breather hose that goes into the carburetor. I'm completely unsure if it made a difference and the bike is excellent. It will even get better when I put the new tire this week.

[Metalefty]

I did spray carb cleaner all around the engine twice and no change in rpm, I especially paid attention to the intake boot. The plug is a BR7ES and it was a little dark but that could have been from eccessive idling from checking for leaks. Exhaust seals are tight. Maybe a different plug heat range?

[Enmerdeur]

Not at our altitude a 7 should be fine.

I still think it is a fuel issue. Try adding some octane booster to your fuel and see if that helps.

[Metalefty]

I bought some octane booster, emptied the tank completly back into my storage tank added booster, mixed it up and refilled my bike tank. I took it for a 10 minute spin around our circular driveway to burn off some of the float bowl fuel amd after the 10 minutes it seemed to be working but I won't know for sure until I ride tomorrow. The decel popping does have sort of a pinging to it so maybe it does need higher octane. Ripping up through the rpms's seems normal though. And also a fresh plug.

[Darkside]

I still think it is a fuel issue. Try adding some octane booster to your fuel and see if that helps.

I would agree. My 14 300 race was getting pipe bang on decel. I started mixing race gas 1 gal race to 3 gal pump 91. Last ride I ran out of pump gas and mixed 2 gal race to 1 gal pump. It ran the best it ever has. smooth bottom to a snappy on the pipe. absolutely no knock or pipe bang on decel.

[GMP]

Did they raise compression in the '14 Race/'15 standard? My '13 Race and from what I have seen of '14 standards run flawless on pump 93, at sea level.