Developed a lot of deceleration popping… With no changes to machine

[F 18 Driver]

Hi everyone,

I could use a little help

My bike (1996 Vmax) has suddenly developed a lot of deceleration popping… (I've made no changes to the machine just started to occur as the weather got colder)

My current set up:

Running hole shot exhaust 4 into 1


6 months ago I re-jetted and serviced carburetors.

All new internals, including small jets 37.5 main jets 150 and replaced float bowl needle seat valves. All replacement jets and needle seat valves Mikuni no Chinese cheapies


.
CORRECTIVE MEASURES I'VE TAKEN TO ALLEVIATE POPPING

1. Check carburetor joint boots sprayed starter fluid around joints looking for indication of leak. None was found. Thereafter, I retightened carburetor joint boots

2. Synchronize carburetors.



CORRECTIVE MEASURES AM CONSIDERING, BUT HAVE NOT UNDERTAKEN YET.

1. Replace spark plugs, but I doubt if this is the issue because they have less than 3000 miles since I replaced all spark plugs

3. Check the exhaust for leaks. There doesn't appear to be any



Therefore, I am left scratching my head and pulling at straws.



Maybe somebody with firsthand experience will able to point me in the right direction.

Thank you for your time and consideration



F-18 driver

 

[Parminio]

You're running too lean. Richen up your mixture a bit. Another quater to half turn out on your mixture screws should do it.

Edit to add: A way to test this is to ride with the choke on a bit. If it stops the popping, that's your issue.

 

[Spyglass]

...watching

Back in the day, guys with small blocks and straight pipes were glad when they developed a "happy little pop" on deceleration once the temperature started to drop.

I would occasionally get some from my 408 Windsor with a 14.6 AFR at idle.

 

[brian hicks]

My Norton Commando used to pop like hell due to air leaks at the exhaust flanges.

 

[F 18 Driver]

Hi everyone,

Parminio, I took your advice and backed out the air fuel mixture screws about 1/4 of an inch…

There's a significant change in the machine running much smoother with much more low-end torque.

On the freeway. No popping at all on deceleration.

However, city riding around town still popping, but to a much lesser degree.

Special thanks to Parminio and all others who contributed with their thoughts and comments.

F-18 driver