My bike while riding continues to stall, backfire and pop and shut off..

Backfiring is caused by a lean air/fuel (A/F) ratio. A leaner A/F ratio takes longer to burn and will continue to burn in the exhaust, hence the backfiring. Is the bike stock, or have you changed the air cleaner or pipes? Both of these changes will result in a leaner A/F ratio. HD bikes with fuel injection already run lean to meet emissions requirements, so changing pipes, etc. will make the problem worse. If you have not made any changes to the bike, make sure that the fuel system is clean and you are using good quality gas. You can also have the bike's computer (ECU) remapped to run a little richer. Your dealer may be able to do this for you, or there are aftermarket ECU tuners available for your bike that can adjust the fuel map and ignition. These will give you the added benefit of more power and a cooler running engine.

4000 rpm ???????

What if anything did you do to the bike recently? Has it always done this since you've had it?

I’m happy to help further over the phone at https://www.6ya.com/expert/al_e83b1941f9c0f302

the igntion module on the right side of the motor is probably bad its a typical issue with sportsters, if you heat the area around the timer cover with a heat gun and then try to start the bike and it wont start then you know its the ignition module on the sensor plate.

could posibly be a problem with your stator

had a similiar prob with a triumph. It backfired at low revs, a delay between throttle opening and revs increasing and bike felt like it wanted to stall at low speeed. Got the Carbs cleaned to find out the problem was infact Failing Ignition coil. Get those checked first before commiting to replacing other parts.

check the cambelts on your bike, make sure they havent jumped a tooth on the timing.

TL

ide start by inspecting / prob replacing the sparkplugs,but also check the fuel pump wire plug under the tank,replace fuel filter inside tank, check earth wirers are clean and check the stator wire plug havent started to burn and melt the plug just cut it off and solder with heat shrink then will have good charge, hope this gives some ideas where 2 start

I'm pretty sure the multi was never an 800. Def cause for a lot of problems. You could bandaid fix the situation w/ a custom dyno-tuned pc3, starting w/ a map from a multi.. It would end up costing you around $500-600 all said and done. perhaps it's time for a DP ECU specific to the S2R 800. good luck

sounds like the throttle cables need to be looked over .( he get everything back to where it was before the lubing?)as one may be out of sync with the other. the oil change has NOTHING to do with the sputtering and surging ,stall .it would only apply if the clutch was slipping and that would make the bike rev with the car oil.