Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 998 / 996 / 916 / 748 > 748 misfiring.....

[Gordon H]

After spending some time on an m900 and 900ss I decided to get a 748 - so I now have a misfiring 748 which is driving me nuts.

The misfire only appears to happen after I've used around 90 miles worth of fuel then the misfire kicks in - won't rev and sounds very sick. Changed the plugs, drained the tank and replaced the filter - all fuel lines look ok / no kinks, breather is clear. It starts first prod from cold and will restart even after the misfire kicks in. Refilling the tank appears to solve the problem - until the fuel level gets down to around the same point....... any ideas?

Thanks G.

[antonye]

Don't go below that fuel level?

Sounds like you may have a split in the fuel supply hose which is getting air into the line. While the split is in fuel, it will continue to pump without problem as it will be sucking fuel in. Once the fuel level drops below the split it will be sucking in air from the tank and not fuel.

Take the pump out and check the connections to make sure they're secure and that you haven't got any splits. Worst case scenario is to buy some fuel hose off ebay and replace the lot to be sure - shouldn't cost you more than a tenner.

[Gordon H]

Originally Posted by antonye

Don't go below that fuel level?

Sounds like you may have a split in the fuel supply hose which is getting air into the line. While the split is in fuel, it will continue to pump without problem as it will be sucking fuel in. Once the fuel level drops below the split it will be sucking in air from the tank and not fuel.

Take the pump out and check the connections to make sure they're secure and that you haven't got any splits. Worst case scenario is to buy some fuel hose off ebay and replace the lot to be sure - shouldn't cost you more than a tenner.

Thanks for that - yeah, I did consider just regarding the 90 mile mark as a reduced tank range.

Looks like it's out with the pump / filter assembly again this weekend. Cheers G.

[antonye]

Originally Posted by Gordon H

Thanks for that - yeah, I did consider just regarding the 90 mile mark as a reduced tank range.

Don't moan, that's more than I get from my Hyper!

[Ghost]

Make sure that you get fuel hose that can live with being submerged in petrol, some can't and degrade.

[Gordon H]

Originally Posted by Ghost

Make sure that you get fuel hose that can live with being submerged in petrol, some can't and degrade.

thanks - probably would have missed that!!