Gilera Nexus 500 Fuel Pump issue ?

[hrccsparky]

Hi All,
I'm having an issue with my 2004 Gilera Nexus 500 and looking for possible causes.
The fuel pump stopped working and upon its removal was confirmed as dead. A replacement was procured and fitted but the engine would not start, then it too stopped working so procured and fitted another one followed by a new pressure regulator and injector to be on the safe side.
Engine now starts and ticks over, but will not rev.
I'm unable to find a new complete fuel pump assembly, so does anyone know of one or what the issue might be if not fuel related.
Thanks.

[capitano]

I remember that on the x9 500s the impeller on the fuel pump could distort, so it was prevented from spinning up to speed.

That's about the extent of my knowledge, sadly. It's been 17 years since I last owned a 500 Nexus Mk1. I still remember how much fun it was, though.

I believe that the X9 forum is still around (Mottza on here is an admin there.) Also Modern Vespa still has a number of Piaggio Master engined scooter owners. Either of those may be a good place to ask as well.

[Andym]

Air filter, tank breather, fuel pump or electronic limiters are likely to be part of the problem.

Given you've changed the fuel pump and got a different result I'd stick to that line of enquiry. Was the replacement pump second hand?

Tank breather and air filter are easy to discount. Open the filler and the air box.

A scooter isn't going to have limp modes and other car emissions type stuff, but is there a warning light and OBD information? No light, it's not that.

Andy

[roadster]

There are some Piaggio machines which require the driver to be seated before they will respond to the throttle. This was done using a sensor in the seat which could be bypassed if necessary. I'm afraid I have no idea whether this model was likely to be affected or what part of the electronics was involved.