Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > Supersports: SS / SuperSport / Supersport 950 > She refused to start...

[paynep]

Another thing, is it typical for the 750 to be utterly un-rideable below 3000 revs?

Nope, with carbs balanced properly the 750 will pull from idle, but maybe not in 4th/5th!

Trust me, I had to get ours smooth as it was Kirsty's first bike.

[paologray]

paul, i was hanging around the bike with the air filter removed (we've all been there), i noticed a black slide over the trumpet to the carb... it didnt move when i gave it some throttle... what is it?

[paologray]

YES!!!!!!
Finally! got her to start! after days of re-charging and killing the battery turning over the starter, she gave me a shout!

i decided to remove the top sparky to make sure there was a spark... well there was, but it was arcing out straight onto the head and not to the electrode. so a simple wipe with the most oiliest of rags and back against the head to test the spark... it was like a 5,000,000 candle watt torch going off in me face!

brill!

[paynep]

Originally posted by paologray
paul, i was hanging around the bike with the air filter removed (we've all been there), i noticed a black slide over the trumpet to the carb... it didnt move when i gave it some throttle... what is it?

if the engine wasn't running then that is the carb slide which has the diaphragm above it and the needle poking out the bottom, and when you twist the throttle you operate the butterfly which is closer to the inlet (not like slide carbs on a 2-stroke when you lift the slide with the throttle).
If the engine was running, then f8ck knows!!!:P

[paynep]

Originally posted by paologray
YES!!!!!!
Finally! got her to start! after days of re-charging and killing the battery turning over the starter, she gave me a shout!

i decided to remove the top sparky to make sure there was a spark... well there was, but it was arcing out straight onto the head and not to the electrode. so a simple wipe with the most oiliest of rags and back against the head to test the spark... it was like a 5,000,000 candle watt torch going off in me face!

brill!

I had a similar problem with rough running and went and bought some new plugs which made no difference. Spent a while (!) sodding about and then decided to try some old plugs which I had lying around. She ran like a dream so I took the "new" plugs back and tried some NGK ones and all was fine.

Not sure what the moral is, but hey.....

[skidlids]

Originally posted by paologray
i noticed a black slide over the trumpet to the carb...

New one on me if it was under the trumpet then as Paul says it would be the slide, but if its above the trumpet ?????????????????????????????????

[bambam]

Originally posted by paologray
Another thing, is it typical for the 750 to be utterly un-rideable below 3000 revs?

What do you mean un-rideable paologray? The reason I ask is that my 750 Sport is a bit ... erm ... awkward under 3000, probably best to describe it as a bit 'over-responsive'.

kwikbitch has the same bike as I do, and she's suggested a mod she did on hers, which was a change of rear sprocket. Apparently that smoothed things out a bit.

Not sure if your problem is the same, but thought it might be worth a mention.

Cheers,

- bambam

[phil_h]

Originally posted by bambam

What do you mean un-rideable paologray? The reason I ask is that my 750 Sport is a bit ... erm ... awkward under 3000, probably best to describe it as a bit 'over-responsive'.

kwikbitch has the same bike as I do, and she's suggested a mod she did on hers, which was a change of rear sprocket. Apparently that smoothed things out a bit.

Not sure if your problem is the same, but thought it might be worth a mention.

Cheers,

- bambam

All of the carby twins can get lumpy below 3k.
1. Throttle synchronisation is _really_ important.
2. Std idle mixture is _way_ too lean - you need to run about 4 turns out - cos weak mixtures at idle produce uneven firing.
3. The ignition advance curve is too aggressive really anyway, and can cause poor sparking under low-rpm-load, and makes all of the above worse, but you cant do much about it, except fit expensive coils so you get a better low-rpm spark.

Work on the first two and you will get it in better shape.
The 750's are smoother than the 900's, believe me.
My wife doesnt like the way the 900's develop power low down cos she says it makes it very jerky to ride, so I tell her to ride faster

[paologray]

well, yeah... its just really jerky. one minute your fine, then the next it feels like its going to stop and get on top of you!
Im goin to try the oil change on the clutch tonight... lets hope it sorts the slip-out...
how do i adjust the idle mixture? does some one have a diagram? or what page in the WSM is it on?

paoaloaaoaoaoaoajshsdhdhrfjkhkfhwhwcnlcna;fhqiw;!

[paologray]

okay... this is the story!!!

Recharged the battery all night 2 days ago, refitted it and it fired up fine, revved her up for a couple of minutes just to get her warm then retired for the night...
Just been out to start her up again and she wont start... grrrrr
so I took out the top plug, checked spark against the head and it was rubbish. so i clean the plug, test the spark again and its sparking fine. put it back in the head. wont start. still!! took plug out again, same problem, crappy spark (sparking out on the engine-not on the electrode), clean it, put it back in. hit the starter and ****KKKING BOOOOOOOOOM!!!!!
the loudest backfire ive ever heard!! considering im in my garage too. my ears are still ringing!
so, I eventually killed the battery trying to start her after 40 minutes, bugger.
It did flutter once right at the end of the batterys life, only to die cos i wasnt quick enuff on the throttle. shite!
Is this mainly to do with the battery?
my garage stinks of fuel so it cant be a fuelling problem...
And I tell thee what... Its ever since i decided to put that rubbo 97 octane stuff in her...