Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > Supersports: SS / SuperSport / Supersport 950 > Power and misfire problem

[Courageous]

Hi there,

I recently bought a '99 Ducati 750ss with injection and rode it down from Liverpool to Spain. Somewhere around Paris I became aware of a misfire or general lumpiness below 4k rpm. At 5k she pulled away sweetly.

I persisted with the trip and upon arrival here in Spain changed the plugs in the hope that they may have been breaking down under load and temp as it manifested itself only after the bike warmed up. The plugs made no difference.

My mate had been telling me that there was nothing wrong and that Dukes tend to feel lumpy at low revs and just stay higher up the power band. He also said that the bike would rev to infinity as it doesn't have valve springs.

With that advice in mind I set about really giving it some and discovered that in 3rd gear on flat ground she wouldn't pass 6k rpm which equates to 90mph. Added to this she started clearly misfiring and popping from the exhaust!

I'm going to present the bike to the local duke dealer but wanted some ideas before I go there as I really don't want to be ripped off (what with the language barrier and all).

I'm therefore hoping that there are some duke guru's here who MAY be able to make some sense from this and try to help......

Cheers guys!

[keefer]

welcome to the site.
err your bike will have a rev limiter. but I cant remember what it is set at on your bike, but would imagine its a bit higher than 6000.
probably got a blocked fuel filter, which is a common problem

[Courageous]

Keefer - thank you for your kind welcome and suggestion! Will look into that one - revs seem to cap out at 9k.

Cheers!

[keefer]

yep that's about right.
fuel filter would be my first call
then plugs which you have done
HT leads
coils
the list goes on. but start at the simple things then just work through it.
unless you bought it off a dealer, in which case I would just chuck it back at them to sort out

[Courageous]

Hehe! Dealer is 1400 miles away! Where is the fuel filter?

[keefer]

are your still there. sorry.
filter is in the tank.
now I don't know my way around the ss model.
but you normally get at them by dropping the pump out the bottom of the tank.
hopefully someone with your model bike will be along to guide you through it.
make sure all the leads are nicely pushed together while your looking around it also

[Courageous]

Hi again Keefer! You virtually hit the nail on the head with the fuel suggestion but it turned out to be the tank vent pipe which was kinking!!! So took her out on a test ride into the pyrenees and she was running sweet as a nut....... stopped off for a photo op and couldn't get her started again! The bleedin Datatag decided to shut the fuel off completely! Had to bypass it and we were on our way again. Who'd ha believed it eh? Anyhow, thanx again for ya help!