help bikes backfiring

[knight rider]

when changing down into 1st the bike started making a loud popping sound I thought ohh well proberly just reved it to high when changing down. next day decided to see what 95 would be like in my bike (I've always used 91) after work I noticed a flapping type of sound coming from the fron somewhere around the header pipes. Bike picks up speed well & have no problems with loss of power or anything like that. Still backfires & when you rev it & hold it at whatever rev (about 1/4 throtle) doesn't sound smooth it sounds like its reving up & down but not alot

am thinking is it just the fuel & nothing major about the backfiring before hand? or is it something more? will be having a good look at it 2moro. & suspecting maybe a hole in the front of the exhaust header pipes? maybe a worn gasket?

any ideas much appreciated

Thanks KR

[xwhatsit]

Sounds exactly like there's a leak in the exhaust manifold somewhere; I had a leak in my headers once that first showed up on deceleration, and then went on to make that `flapping sound' you mean as the leak got worse before I worked out what it was.

Shouldn't have anything to do with the fuel, should it?

[knight rider]

not sure about the fuel as it started to happen about the same time. Is it an expensive job to repair a hole?

[Paul in NZ]

Could just be one of the header manifold flange plates coming loose??

[knight rider]

Could just be one of the header manifold flange plates coming loose??

was header pipe coming loose was tightening them all up & found 2 were loose on one pipe. Bikes back to normal now :)

Thanks everyone