missfire/banging in the exaust starting just around 3200 rpm

[bobst2]

completed coil & main power upgrade. when bike warms at around 3000-3500rpm getting banging out the exaust.does not seem to do it cold.i had this problem before the upgrade. think that is about when the advance kicks in.
had a new coil kicking around so installed it & no change swaped it to other cyl still no change.

ideas appreciated. (mabey a tight exaust valve ?)

[higgy]

Banging ? like popping ?

Could be a tight valve

[jayh]

On acceleration ? Or on the overrun ?

If it is on the over overrun, it can be a lean or rich idle mixture,or if you have a weber fitted too small or too large idle jet .Or leaks in your exhaust clamps/gaskets.

With my weber the closer I get to correct tune the less popping,and when the idle jet is right none. J.

[bobst2]

loud banging/ popping out the back of the pipes.yes

[higgy]

What kind of pipes you have Bob
Makes a difference.........

And is that running or ridding ?

[paso750]

and what about your carb synchronization?

G.

[bobst2]

it has a set of conti alloy can type pipes. it does it both rideing and just reveing it up without any load.
carb was balenced with an airflow meter made for weber carbs. i was checking temp with a infra red temp gun were almost identical.

i wonder if i should try it with the choke on a little bit to see if the rpm changes
before it bangs(lol it scares the shit out of some of the people in the neibourhood)

[bobst2]

the warmer the bike gets the worse it gets

[Derek]

the warmer the bike gets the worse it gets

Sounds like a weak mixture due to a blocked carb jet. If the bike sat around for a while with fuel in the carb it could be due to it evaporating and leaving a gum blocking a jet. Modern unleaded is very bad for this.

[bobst2]

i dont think so i had the carb apart a few months ago when i first got the bike carb was pretty clean in side i put a new inline filter & a new in carb prefilter and had new jets so put then in at that time 55,s i think. i am gonna see that the guys here think before i take it apart again. in the mean time gonna try to run it with a little choke out in the shed & see if anything changes. will post results

[higgy]

get your self a piece of 1/4 inch plastic tubing about 6 feet long
hook it up to the manifold directly to the fittings that supply the ecu
run it over the handlebar on one side to form a u, the u doesnt have to be very large. add a few cc of oil so that you have enough to cover both sides of the u with 6 or 8 inches of oil. Then do the carb sync
the idea is to get both sides of the u oil levels to be even
even at idle and even as best as possible to about 4k rpm

once this is done you can call your carb properly synced

it is not possible to sync the weber with a vacuum gauge, you can get close with 2 but a u tube manometer is cheap easy and accurate and easy to do at home

vacuum gauges are based on metal tension
U tube manometers are used to calibrate them as best as possible


once upon a time a manometer used mercury
but all that is needed is a viscous fluid...oil works great, even better than mercury..any oil, olive,mineral or my personal favorite old engine oil

[paso750]

do you have the original airbox or are you using some bolt on sports filter ?

G.

[jayh]

Start simple, Even near new spark plugs can play up,replace them as most carbed ducatis have a habit of fouling them.Check your leads aren't shorting or replace them if in doubt.Check all of your coil connections for corrosion inside the connectors and good earths.

Your filters are all good as you just replaced them but what about crap in your tank outlet is that running freely? J

[paso750]

yup, and check you`re using the correct spark plugs. Which ones do you have ? Incorrect plugs are not the reason for your problems but they could add to it.

G.

[higgy]

JAY & G


R U paying attention ?