So I've got a small issue with my engine having a slight miss on idle plus a bit of overrun backfiring going down hills mainly.
Am I correct in assuming carbs need syncing/ dirty fuel/spark plugs?

all input appreciated

cheers
mal

I had to smile to myself the other day when I was backing off quite hard from forth to third coming up to a dual lane roundabout and as I passed a car in the inside lane my old girl let out an enourmously loud crack. It startled me so I can only imagine how the driver felt .

She had been fluffing and farting a little for a week or more so when I got home and she cooled down I tightened up the exhaust header bolts. They were a little loose. All good now.

You could also check the exhaust valve clearances if its been a while. They may be a bit tight.

My (little) experience is with KH: check the valve clearances first and then look at balancing the throttle bodies.

What bike? (It helps to put your year/model in your signature.)

If it's a K75  then it's normal for them to backfire under moderate to heavy engine braking. Once you've owned/ridden a K75 for a while it will subconsciously teach you not to do that.

sorry, 1993 kl1100lt
seems to do it more on the cold mornings which we have  had allot of lately, 2 degrees at 5;00am on the old k bike this morning, great way to start the day

I had a K1100RS a few years ago that started backfiring.  In my case it was my own fault.  I had been messing with the idle adjustment using the throttle stop screw (like you do on a K100) instead of using the brass TB screws; this had thrown the TPS adjustment out.