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

[khu996]

Just had a Termi half system fitted to my otherwise standard 749, together with a Power Commander. On the way back home, its backfiring rather a lot.

What could be wrong?

[khu996]

No Dyno time unfortunately, just a map from the Power Commander site, and only backfiring when i come off the gas. Otherwise it runs well...

[khu996]

Thanks mate, I thought too much fuel aswell, and theres nobody close to me with a dyno, lets hope someone can shed some light!

The Termi system was bought from another member on the board, it was the back box, the cat-free pipe, and the air filters. Is this whats known as the asymmetric system?

[Twinfan]

Yep, that's the asymmetric system. I take you're still on the standard ECU? I'd put a blank PCIII map on (i.e. everything zero) and get yourself booked in for some dyno time to set it up. Then a brief trip to a dealer to get the CO2 adjusted and you're sorted.

It'll be set-up thing and all the above should cure it.

[gasmanrus]

hey khu, make sure the pipes are connected together properly & you have no air leaks. i had the same problem when rolling the throtlle off.

going down a long hill on a closed throtlle, crack it open at the bottem then BOOOM!!

great for scaring old ladies

[Edited on 13-1-2005 by gasmanrus]

[khu996]

Yup, standard ECU, the PCIII was pre-loaded with the asymmetric system map from their site...guess its not ideal.

I know dyno time is the right way, but is there anything I can do to cure it for the time being?
Will the CO2 check help? Or perhaps a different map from the PCIII site?

[khu996]

Would it be better, for the time being, if I loaded it with a zero, stock map?

[dickieducati]

only really repeating what others have said but you really need to take it to someone that knows what they are doing and get it set up correctly. and from my experience dont fanny about with any old ducati dealer, take it to one of the recognised 'experts' that are mentioned regularly on this site.

n.b not all the 'experts' are official ducati dealers b.t.w

[madmav]

KHU ! some of the maps you down load can be (DIRTY) maps and will conflict with the pcomander!

JHP at cov is the place to take it as John will set it up real sweet on the dyno!

and what has been said about air leaks is very true! as you shut off if air can get in the zaust it will back fire on the overun!!

to be safe get it sorted asap (DETINATION ) can seriously damge your engine !! ,,,,,,,, mav

[Edited on 13-1-2005 by madmav]

[khu996]

Id love to be able to pop up to JHP, but its a bit of a ride from Swansea.

Alan at AJ Racing fitted the exhaust for me today, top bloke, but unfortunately, he doesn't have a dyno. Wheres the nearest reputable place to me?

Oh, and one final question, how many holes are there in the pipes (the ones that are bunged up, used for probing the emmissions)?