View Full Version : Help with Ducati diagnosis please.....
neels
24th January 2020, 17:19
The dirty old ST2 is being a pig, and I'm out of ideas.
Won't start or idle without the choke (well, idle adjust) almost completely on, usually it will idle happily with it completely off unless it's really cold.
The thing revs ok, but when being ridden when the throttle is opened it coughs for a bit, then picks up and runs normally.
Have had a couple of problems in the past with electrical connections, so have cleaned up the usual suspects without any improvement.
Any suggestions gratefully received.
Bonez
24th January 2020, 17:23
Bad fuel maybe?
husaberg
24th January 2020, 17:45
Pretty sure the faualt lies with Italian manufacturing;)
neels
24th January 2020, 17:57
Bad fuel maybe?
Could be, although it hasn't been sitting for long, suppose I could drain it and chuck some fresh stuff in to cross something off the list.
OddDuck
24th January 2020, 19:14
Hi Neels
I'd suggest checking the O-rings sealing the inlet manifolds to the cylinder heads. Ducati didn't use a gasket here for once. If they've gone then you'll have vacuum leak and lean mixture, especially at part throttle / starting. I'm just about to change mine out after having realised that they're almost certainly 20 y.o. originals and will have squashed flat over time.
Unfortunately on the ST2 it's a pig of a job. To get clean access, the tank's got to come off, then the airbox, then the injectors. Do you have a set of vacuum gauges?
Grumph
25th January 2020, 05:29
I'd do a vacuum synch before anything else. When there's a TPS on one throttle body - or carb for that matter - and it goes out of synch with the other, the map for that side goes out of phase. What you're experiencing seems to be the common symptoms of this.
To do it right of course means checking valve clearances too...
jim.cox
25th January 2020, 07:26
Could be, although it hasn't been sitting for long, suppose I could drain it and chuck some fresh stuff in to cross something off the list.
That's definatly the easiest place to start.
As well as stale fuel, you might have water in tank from condensation on the inside.
Make sure you drain it completely, as there is often a little left over the tank even on reserve.
F5 Dave
25th January 2020, 18:15
Injected bike seem keen on giving up with a bit of water. Drain or pump out as much as possible and add some meths. Shake Then add fresh gas.
OddDuck
30th January 2020, 21:14
Hi Neels,
Have just found what look like cracks inside both inlet manifolds on my ST2, under the rubber boots. The boots themselves look like they've gone hard and started opening up from the aluminium. I've put photos in the Summer Running thread.
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