Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 999 / 749 > 749S Misfire

[GeoffDuc]

I've got a Ducati 749S (2003) that's recently developed an intermittent
misfire.
Last run it went onto 1 cylinder for a couple of seconds then
cleared, then the same happened again. It was then fine all the way back (40 odd miles).
Started up fine this morning, after about a mile it went onto to 1
cylinder, backfiring then would chirp back onto 2 cylinders then down to 1
again. Managed to get it back virtually 1 cylinder all the way (1 mile ). Had a good look over it but nothing seems obvious.

Any advice/cure would be greatly appreciated.

Thanks
Geoff

[Carbon749]

Not had any problems myself, but, have heard many many 749 and 999 owners talk about problems with coils / spark plug caps. Seems the front one is the obvious one, gets hit by all the crud from the front tyre.

Take it off, give it a good clean, loads of WD or similar and put it back.

I'm sure someone who has first hand knowledge will be along soon.

[andyb]

Mine are also kind of glued in with a silicone as well!...........

[bike mad]

my one was the back cylinder, lot's of water and crud and thats with a rear huger,

[Wylie1]

As mentioned already, it does sound like a faulty coil. You can tell which cylinder isn't firing by checking which exhaust pipe isn't getting hot.
Once you've identified the problem cylinder, remove coil & clean as suggested above. If cleaning doesn't work, I have a spare pair of coils (used but work perfectly) & would sell one of them. Let me know if you're interested.

[red seb]

Fault :- Water in the plug holes clean coil and plug tops (these may even be loose) spray with wd 40 and seal with silicon jobs a good un! do not buy new coils until you've done the above. Mines done it several times before I sealed them up.

Cheers Seb

[GeoffDuc]

Thanks for the feedback everybody.

New plug (old one was well corroded) and a good clean/spray and I'm back up and running!

Thanks again - Geoff