851 misfire problem ?
 

Any ideas on what may be causing a intermittent misfire on my 91 851 ds?
In top gear and while throttling hard the bike sometimes misfires several times, dropping down to any lower gear and no problems when gassing it hard, only happens in top?, bike starts, idles & otherwise runs perfect hot or cold, damp or sunny.
The bike runs high level sil moto race cans, open top airbox mod, not sure what chip is fitted at the moment but will check asap.
Feels like an electrical type misfire but as it only seems to happen in top gear while accelerating hard, i now think it may be a fueling issue?
Any ideas greatly appreciated :puzzled:

Have you checked/changed the fuel filter?

Thanks for the reply, The fuel filter was changed less than 2500 miles ago according to the service history!, i may change it anyway just to be sure....

My fuel filter was only changed a 1000 miles ago and he fuel pump is struggling to prime (pointing to same)..any other ideas/thoughts Paul..?

Nat

It might be worth changing the relays in the tail. They seem to be related in their functioning with each other and if one is a bit dicky it can affect the fuel pump - cos it happened to me!
The Ducati part seems to have changed over the years and the ones I bought had a different pin arrangement, which I sorted by swapping the pins in the socket block the relay sits in.
Then I discovered that I could get an identical relay to the original from a local motor factor for about a fiver and it saved the hassle of changing connections...

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