Back firing.

[HypnoToad]

Bike seems great until you ease back on the throttle and as the revs come down to about 4000 the engine gives a few back fires. Just started to happen over the weekend.

Is it running lean?

[DefTrap]

Exhaust leak?

[HypnoToad]

I recently had the clutch done so the exhaust was off, and the front cylinder sounds a bit different. is there a test for gas escaping ?

[fabitappi]

Hi Hyp, there are either the headers or the carb inlet rubbers leaking
if otherwise no alteration was made on the fuel intake side.

As for the carbs: spray brake cleaner into the carbs area while the engine
is idling. You´ll might watch the engine rev up by itself if there is a leakage
on the intake rubbers´ side.

[HypnoToad]

Thanks fab ill try that tonight

[DefTrap]

I recently had the clutch done so the exhaust was off, and the front cylinder sounds a bit different. is there a test for gas escaping ?

Did the headers come off or was it just the tail pipe?

You might be able to feel the exhaust gasses escaping if you give it some revs. Obvious place to look is the head/header interface if you had them off? (did you use new gaskets?) or the header/silencer interface (again, what's the gasket. sit. here?) Or either may need a couple of extra turns down to secure it all up.

[HypnoToad]

I just checking the exhaust pipe coming from the front cylinder, the nuts were loose on it.
Tighten them with the tools I had on board.
Hopefully it will do until I get home and I can give them a good tighten.

The headers were off with the clutch replacement and new gaskets were used.

Thanks Fab and DefTrap looks to be solved

[DefTrap]

Sorted.
Careful with those header nuts as they tend to cling to the studs.