Backfiring 999

**Dickie** · 23 Apr 08, 07:44 AM

Hi guys,

Ive got a 53 999 which has just started back firing when it's ticking over

. It's fitted with a RaceFit exhaust on the standard ECU and front link pipe (with CAT) but has been running fine for over two years.

I have looked at a past threads on here (loose air box gasget etc), I've been told that it could possibly be the front coil pack breaking down or my RPM/Timing sensor.

Can anyone offer any other reasons/advice - cheers

**nogaromill999** · 23 Apr 08, 07:56 AM

I would ALWAYS opt to check the simple, easy stuff first...it could be just a plug failing. Then check the coil on the front cylinder before moving onto sensors etc.....just seems logical to me....

**749_MON** · 23 Apr 08, 09:26 AM

Although not a solution to the problem, have I read your thread right in that you have a cat on the front cylinder, but not on the vertical one?

I would have assumed this would cause an imbalance due to differing back pressures?

**Dickie** · 23 Apr 08, 10:32 AM

Yeah the CAT is still in the front pipe but the manufacturer of the can and an independant Ducati dealer have said it shouldn't effect the running of the bike that I would notice.

I have had the can on for 2 years without any probs until now.

**ducati2242** · 23 Apr 08, 04:39 PM

Could be as simple as a leak in your exhaust system. Does it look to be leaking at any of the joints , any black deposits anywhere exept the end of the tail pipe. Coz thats what made mine backfire.

**Triple9** · 24 Apr 08, 04:41 AM

Quote:

Originally Posted by ducati2242

Could be as simple as a leak in your exhaust system. Does it look to be leaking at any of the joints , any black deposits anywhere exept the end of the tail pipe. Coz thats what made mine backfire.

Agreed!
My 999S started back firing last year,...it was sucking air in through a crack in the rear manifold.

**CarsOrBikes** · 08 Jun 08, 07:33 PM

isn't backfiring due to an exhaust leak normally apparent on overrun rather than under load or idle?

......curious if yours were different?

**Ghost** · 08 Jun 08, 07:52 PM

Quote:

Originally Posted by Triple9

Agreed!
My 999S started back firing last year,...it was sucking air in through a crack in the rear manifold.

Strange that T9 mine has fractured 3 times now. I have welded a reenforcement plate over the area to see if that helps