Hesitation!
 

Hi all,

Thought id test your knowledge with this one....
For about the last year or so i have had a cough/splutter and hesitation from the cylinder or through airbox, riding it last night on a smooth surface at a constant 4500rpm i could feel the bike surging just before it coughed.
I have asked Ducati and they are useless, I have had the bike set up on a dyno with a P.Commander so i know its not fuel air mixture, or a dogy fuel relay.
The only thing i can think of is a partly bunged up fuel filter!

Any help would be most appreciated.

THanks

Mark.

So its a fuel injected beasty then...fuel filter would be my next guess too, but thats all, oh how about any fuel tank vent as well?

Good luck

Thanks for the reply,

Im not sure were the fuel tank vent is though....do you?

Cheers

Mark.

Sorry Mark - search the threads on here or or get your Mo-cheeh down to Nelly at www.cornerspeed.co.uk - Nottingham - Pronto !!!

I don't think it's your fuel supply but slighty out of balance TB's will cause this, especially at slight throttle openings. Does it pop back when you start to gently open it and when you are just trickling along at 30-35mph in 2nd gear?

I expect that the PC set up runs where less than subtle when they where running it up on the dyno and unlikly to pick it up.

Regards,

Rob

Hi Rob,

Yeah thats exactly it, slight throttle opening at about 4-5000rpm, doesnt do it every time though and seems worse when the engine gets hot.
I just got a new fuel filter, do you think it;s worth trying that?
Also presuming TB's stands for throttle bodies how do i go about fixing this? can i do it myself?

Cheers

Mark.

The fuel filter is dead easy to fit but it'll take a few minutes to do. I think you can get at your filter through the filler cap hole, same as my 888. Need to pull the filler cap off then take out the tank neck.

Anyway, TB's balancing is pretty easy but if you've never done it before you'd probabaly want to take it to a Pro. Frank mentioned Nelly. If you're near him in Notts, he comes highly recommended.

Rgds, Rob

Ok thanks Rob, I'll try the new fuel filter this weekend to see if that cures it, if not ill give Nelly a ring, starting to get **ssed off with Italia Moto in lincoln, they just dont want to listen, Ive had this problem since i bought the bike 2 years ago from them and they just think it's fuel mixture!. Useless!!!!.

Cheers

Mark.

Mark,

My 888 was similar but a 20min tune up sorted it out. If you want to take a peak down the inlets you should be able to see if they are basically opening at the same rate. It's really senstive from tickover through the first few thousand RPM on a very light load. Try it and you'll see what I mean. You hardly have to open the throttle at all. Get a couple of 3 or 4mm drills. One in the horizontal body and you should have the ame gp in the vert. TAKE CARE NOT TO DROP THE DRILLS THOUGH!!!!!!!!!!!!!

Good luck,

Rgds, Rob

Great, cheers for the advice rob!!
I'll have a play tonight.

Mark.

Just to finish of this thread.... The bike was that bad on saturday that it spluttered out going up a slight hill on nearly full throttle opening, so i managed to get it home and changed the fuel filter, then took the bike out again......Exactly the bloody same...so a trip down to halfords in a last ditch attempt at curing it and bought a bottle of STP injecter cleaner, which has absolutley cured it, no hesitations or coughing all weekend, i cant believe all it was, was a dirty fuel injecter!!! Ive had this problem for a year now.

Anyway thanks for your help!!

Cheers

Mark.

Well, i thought id fixed it but it's back with a vengance.!!
Not only is it still coughing, but it's now spluttered out twice now like it is bogging down and cutting out.
Tonight i was just accelerating away from a roundabout first, second gear into third and total loss of power as if someone had hit the kill switch, wouldnt accelerate at all, i thought id blown the engine or the chain had come off the sprocket or something, strange also the fuel pressure warning light came on but the bike was still ticking over as i came to rest, i switched the bike off, checked round it, ok then restarted it and was fine again no problems.

Has anyone any ideas of what this could be, im coming to a lose end and feel like selling the bike.

Thanks

Mark.

Hi there

..it's a bit of a long shot, but I had an experience where the bike would feel as if it was gathering itself under me, and then backfire as if to clear... turned out to be a bad earth connection, which was cured by a wire brush to all the straps... like i said it's a long shot but I was amazed that such a 'simple' thing could have such a dramatic effect

Cheers :cool:

Dano

Cheers for the reply Dano,

I'll give that a try, ive tried everything else.....

Cheers

Mark.

hmmm,
Like Dano I too had similar problem with electrical connection, mine was on 906.
It was the neutral battery connection which looked as though it was secure but when I nudged the battery the neutral was obviously moving at a different pace.
Acceleration in straight line was causing battery to move in it's holder and the neutral to battery terminal was dirty as well as being not so tight.
Hence, the race from the lights was OK upto about 100 yards when it then started to act like a kangaroo.
best of luck

If it's always at the same rev range it could be the Throttle Position Sensor, that's what it was on my bike when it had similar 5000 rpm-ish problems.

It's only a potentiometer that tells the ECU what position the throttle is at, and the tracks tend to get dirty or cracked. It's also temperature sensitive and gets worse when it's hot

Hi,

I'm having the same problem with my injected ss, been told it the butterfly valve adjustment. Caused by Ducati Performance Cans...
getting it sorted next week!

I thought I'd best chime in here. ...

I've got the same thing happening too! Although not to the point the engine cuts out.

I've heard that it may be something to do with air getting in amongst the exhaust gases because the SS performance cans just slip in and perhaps aren;t a true snug fit.

I had my throttle sensor adjusted last service and it seemed to make acceleration better, but didn't fix the "hesitation" and "popping."

It only seems to happen in the hotter weather - I can't remember it happening much over winter at all. It also happens at approx the 4200 - 4500 rpm range. I fixed this to some extent by not riding with the revs in this range for any extended period of time - I ride generally at about 5000rpm now if the hesitation is happening a lot.

Phill

Ok thanks Chaps,

The bike goes in next month for some warranty work, so i will pass on your suggestions to them....see if i can get it sorted, the hesitation i can probably just about live with, but when it starts dying on me it's getting rather dangerous!

I will probably clean up the battery terminals myself this weekend as per guest1's suggestion as a starting point.

Thanks for all your help!!!

Mark.

Check my thread entitled 'Help! Sick 900ss!', Mark- I had (have) the same problem on mine, though it's more like 3-3500 rpm.

Unclip the throttle sensor plug from the left side of the bike; you will notice greeny corrosion on the centre pin/socket, which can be scraped of with a small screwdriver or spark plug wire brush.

This will sort out the bike for a while. Unfortunately, it's very difficult to clean the contacts completely as the engine would need to be removed from the frame to remove the housing, so the problem will come back fairly soon. I'm changing my plugs next, which should help...

Whereabouts in Hull do you live? I grew up there! (East Hull)

[Edited on 11-7-2004 by 3narf]

Hi 3narf,

Thanks for that, i will check your thread! and try that out.

I live west Hull in a village called Ferriby.

Cheers

Mark.

Hello Again,

Can you give me a bit more info on where abouts the throttle sensor plug is and what it looks like.

Cheers Again

Mark.

i had exactly the same problem on a 99 Sv650. the offending part was a split carb to cylinder head rubber. $90cdn later and it's running like a top again

Just a silly point, but there isn't an ignition cut-out on the injected SS, is there? Clutch interlock? Sidestand interlock?

I've had this problem on other bikes, and it was the result of the bike, at certain revs, hitting exactly the right vibration frequency to cause an intermittent fault. And then, of course, it got worse and worse.

Hi Mark-
 

The connector is behind the LH fairing mount.

Give us a ring on 07734 506418 for more info!

PS My wife's mother lives in Brough...

Great thanks for that 3narf!!!

I'll have a look tonight, do you have to remove the fairing to get to it or see it?

Often drive through Brough, she's maybe heard me thundering past with my race cans on.:lol:

Cheers

Mark

It's much easier with the fairing off and tank propped up. I changed my plugs today and cleaned aforementioned contacts; there's still a glitch around 3000...

Mother Outlaw is staying with us at the mo, seeing as her daughter was due to give birth today!! :o

Typical, she's always late...

cheers, A

Ok Cheers 3narf!!

Good Luck with the new baby!!

Mark. :)