Had this bike for 3 weeks. Ran well on first 3 outings. Then developed low rev misfire and rough running on idle. Battery new, plugs new, air filter in good order and fuel fresh. Now turns over but won't start. Is this a common problem? I think I know the answer to that, as I'm not new to Italian bikes and cannot blame naiivity. I suspect it needs a proper carb clean. But...nice ss people, how common are ignition system failures. These solid state items are not cheap to replace and I would not want to shell out without good cause. Any thoughts where to check first before stripping it down to the bare bones, gratefully received. Cooky
A quick way to check the fuel filter (and the pump).........disconnect the fuel hose at the tank, clean out small fairy liquid of similar squeezy bottle and fill it with clean petrol..........give it a gentle squeeze while holding it in a gravity feed position and try to start the bike.....if it runs, even for a bit; then the fuel filter or the pump need attention.
So we have a bike down. So back to basics, check for a spark at the plug, and see if there is petrol or the smell at least on the plug
Could be a loose flywheel. This starts off as rough running but takes out the pick-ups as it gets looser. You can get new pick-ups from Electrex. As said though, do the basic checks first to determine sparks on both plugs and fuel.
Thanks folks. I will check fuel filter. Discovered bike has Dynojet stage 2 fitted, mutilated airbox but OEM filter (Not K&N), with Silmoto open pipes. Previous owner had carbs ultrasonically cleaned last year and bike has been carefully looked after. Does anyone know best (read cheapest) place to get replacement full filter? I will get carbs reset. Hope to change to standard 42.5 jetting and obtain complete airbag cover. I'm not interested in power as their seems little to be gained going from 75 to 80bhp and the pipes and open box upset the neighbours and local boys in blue (well at least the 2 that are left after cuts!).
if std, you have a 'teabag' filter which is not as easy to find as a conventional inline type - I did find a source for a modern equivalent a year or so back but don't have a link handy so hopefully someone on here will probably best to just persevere with finding if ignition or fuel to start with as your filter /pump may be fine.You could check for fuel using a gravity feed as AL suggested or even 'Easystart' or WD40 directly into venturi* if you're lazy. I prefer WD40 as it's not quite as volatile plus doesn't etch plastics or paint as much. If your 'teabag' is totally blocked you could run a conventional inline filter externally instead making it easier to change next time. Only downside of this is that pump might eventually get to chew larger debris that is often sitting at the very back corner of the tank if it's disturbed. * be well prepared in case of backfire though - eyebrows out the way.
Got a Ducati filter of the bay for £9. I had a similar problem with my 750, Mr Arquebus found the problem, one the the mixture screws was missing an o ring. Might be that one was missed when the carbs were cleaned last time
unless engine is in generally poor tune to disguise things, or owner isn't used to the sound of a normal engine, 9 times out of 10 a missing 'O' ring shows up immediately on start up and any length of time running particularly at low revs.
T Ducati struggled to get these bikes to comply with emissions and noise regs, so the standard bikes are somewhat strangled and don't run that smoothly, especially slow running and idle, so although the mods do improve power, that is not necessarily the main benefit.
Cooky, Should be a link to the filter in this post. 750SS project begins 750SS project begins | Page 2 | Ducati Forum Cheers Gaz
If the bike spent a lot of time outdoors before you bought it, it is likely there'll be plenty of water lying at the bottom of the tank (with your fresh fuel sitting on top of it), as it will get past the seals quite easily - one of the evils of flush fit filler caps.. so you could be trying to run on water, or at best, fuel and water - the symptoms you describe could point to this. Get a syringe and a length of clear fuel pipe, take a sample from the lowest point of the tank - that should tell you whether its the case or not.
