Backfiring at high rpm

[Redneck biker]

I don’t understand wtf is happening to my engine but when my engine reaches a certain rpm there is a pop sound like a huge amount of pressure is being released. If I pull in the clutch at a stop and full throttle the engine revs up and then it pops out pressure in the carb area then a small amount of smoke is released around the carb. I can’t pin point were the smoke comes from but it’s from the carb somewhere. It also happens while I’m riding but a a lower rpm so I could be accelerating and then out of nowhere POP then I lose all power for a second and it goes again. It also takes 20 seconds or so to regain full power after it pops. Sometimes it pops repetedly and I end up slowing down 10mph. It also tends to pop more when at full throttle. Have zero clue what’s going on any help would be appreciated.

 

[gary55]

Pull the head and have a look inside.

 

[crassius]

sounds like it is backfiring a bit - may be a gasket leak or something making it go very lean

 

[Redneck biker]

sounds like it is backfiring a bit - may be a gasket leak or something making it go very lean

Here's the thing about the gasket situation. The gasket under the cylinder has a very small amount of oil in certain spots but that's after 500km of riding. I can't tell if it's the crankcase seal because there's no oil around either of the seals. I have the c clip at the lowest setting and the plug is black. The head gasket is not leaking. My carb has no vacumm leaks either

 

[LewieBike]

Start at the fuel tank and work your way towards the carb. Test everything for free flowing of fuel, the pre-filter on the fuel tap, the fuel filter, and the spigot and float needle valve seat in the carb. Check everything carefully for gunk and debris. Check that the float is set to the correct height with the carburetor float bowl off and the carb body upside down.

Reread the carburetor troubleshooting guide in the sticky area above and double check against all the offered solutions.

This is a gravity system and needs to be extra clear and open so you get enough fuel when you're pulling a hill at speed. Popping and backfiring is usually a sign of insufficient fuel being delivered when needed.

 

[Redneck biker]

Start at the fuel tank and work your way towards the carb. Test everything for free flowing of fuel, the pre-filter on the fuel tap, the fuel filter, and the spigot and float needle valve seat in the carb. Check everything carefully for gunk and debris. Check that the float is set to the correct height with the carburetor float bowl off and the carb body upside down.

Reread the carburetor troubleshooting guide in the sticky area above and double check against all the offered solutions.

This is a gravity system and needs to be extra clear and open so you get enough fuel when you're pulling a hill at speed. Popping and backfiring is usually a sign of insufficient fuel being delivered when needed.

This makes a lot of sense because the fuel tends to not want to fill up the fuel filter. It also leaks out of the filter area even after I have bent the prongs. I'm not sure how to stop it from over flowing though.

 

[Redneck biker]

Well I've made a new discovery. When I full throttle my bike at low rpm it not only backfires but spits fuel out the fuel filter side of the carb. I was riding without a filter and I full throttled the put my hand in front of the carb and air and fuel was going out the carb onto my hand and covered it in gas. I could easily feel air as well coming out of the filter side of the carb. I'm not sure if this is contributing to the backfire or not but now I'm even more confused