Backfiring periodically on decel/ CO issue again

[fouramdesigns]

I have an 01' S4 with the Termi's and ECU, bought used. I keep getting a little backfire every so often, and when I throttle at a light, I hear a "pop" in the throttle buddy under the tank. Just kinda worries me if the bikes running to lean or rich. I just had the belts serviced, new chain. But haven't had the valves adjusted, which I like to learn to do myself. Just trying to figure out what this issue is first.

[EEL]

I had this problem with my arrows so here a list of possibilities that you should look thru. If you do it in this order you'll avoid unnecessary servicing.

1) First identify whether you're running rich or lean
a) Does your exhaust smell like gas? If so, you might running rich.
b) When you flog your throttle does it lag/lurch before the power comes on? If so, you're probably running lean

2) Check for exhaust leaks - DP ECU's(and most power commander maps) tend to richen the mixture. An exhaust leak at low throttle will many times can cause an inrush of air into the exhaust. This results combustion of the unburn fuel. Check for leaks by feeling around the slip fit connections. These are usually the culprit. From first hand experience the horizontal cylinder tends to run richer. I've noticed in the past that exhaust leaks contribute to a majority of excessive popping and backfiring situations.

3) Clean your air filter. You want to make sure you're engine breathes properly

4) Valve adjust/ Sync throttle bodies / reset TPS - A valve adjust should be your last resort as this is generally and expensive procedure. But hey, sometimes thats what it takes. Just dont jump to this right away.

[fouramdesigns]

Thanks for the quick reply. I will try those. One thing that worries me, I was unloading the bike, it fell over with me, and dented the bottom of my right Termi can, busted the riveted ring loose, looks cosmetic, but hoping the can is not damaged and leaking. I've only had the bike a short while, so I can determine if this was an existing issue.

[booger]

+1 on the exhaust leak, I had the exact same symptoms you described after I installed the Termi ECU/airbox. One of the exhaust clamps was loose, after I tightened it no more coughing.

[NekkedChic]

OK so yes, I am about to ask a noob (mechanically) AND chic question, but bare with me here please:

Installed Leo Vince slip ons....told no need for re-tune with these.  I DO get an occasional pop on deceleration, but (wait for it) I LIKE this.  So, this is a "bad" thing perhaps?? 

I am coming up fast on the 7500 mile service for my '09 696 tho-is there a problem waiting til then for any issues? 

Also, trying to find thread/link that tells me exactly what all needs done at this service.

Thanks all for putting up with me here. 

[Slide Panda]

OK so yes, I am about to ask a noob (mechanically) AND chic question, but bare with me here please:

Installed Leo Vince slip ons....told no need for re-tune with these.  I DO get an occasional pop on deceleration, but (wait for it) I LIKE this.  So, this is a "bad" thing perhaps?? 

I am coming up fast on the 7500 mile service for my '09 696 tho-is there a problem waiting til then for any issues? 

Also, trying to find thread/link that tells me exactly what all needs done at this service.

Thanks all for putting up with me here. 

That popping is probably as described above - the result of a small leak in your exhaust.  One of the joins where your new slip ons meets the headers has probably worked a bit loose since the install.  IF that's the case it's not a huge deal.  It's not good, since it's not supposed to run like that.. but you're not in immanent danger of you bike blowing up.  There's probably no problem waiting until your service - but really there's no need.  All you probably need to do is loosen the cans, give them a wiggle to make sure they are snugly mated to the headers and then re tighten anything you loosened.

Your owners manual will tell you what needs to be done and any given service.  IF you don't have yours - Duc puts them on line
http://www.ducati.com/en/bikes/service/manuals/2008.jhtml?family=manuals

[NekkedChic]

That popping is probably as described above - the result of a small leak in your exhaust.  One of the joins where your new slip ons meets the headers has probably worked a bit loose since the install.  IF that's the case it's not a huge deal.  It's not good, since it's not supposed to run like that.. but you're not in immanent danger of you bike blowing up.  There's probably no problem waiting until your service - but really there's no need.  All you probably need to do is loosen the cans, give them a wiggle to make sure they are snugly mated to the headers and then re tighten anything you loosened.

Your owners manual will tell you what needs to be done and any given service.  IF you don't have yours - Duc puts them on line
http://www.ducati.com/en/bikes/service/manuals/2008.jhtml?family=manuals

Thank you so much for the info and links 
I will get my SO on the tightening job, as he is the "installer" 

[Buckethead]

Thank you so much for the info and links 
I will get my SO on the tightening job, as he is the "installer" 

Oooooh...

If that ends up being the case, jar-opening jokes are necessary.

[fouramdesigns]

Spoke with the dealer here in Nashville that did the chain and belts. He says it needs to be hooked up to the CO machine. That the bike is probably at about 6%, needs to be blowing about 3%. Going by the symptoms I described to him.

[OT]

The other exhaust fittings to check are where the headers bolt into the engine....that solved a similar problem I had 

[fouramdesigns]

I got to thinking, I just got back in from the Gulf, took a ride and noticed the air box is not as throaty as usual. Makes me wonder if the plug is fouled. I cranked it up last night, got a loud backfire pop, same usual heavy gas smell from the exhaust. I plan to take it to the shop Saturday. But seems if the previous owner spent all the money on the Termi setup, he would have had the ECU calibrated as well. Hate to spend the money if it's just the plug which I can replace. Any thoughts on this? It's been so beautiful here, I've wanted to ride, but the Duc is running like crap, so kinda takes the joy out of the ride.

[EEL]

So you checked for the exhaust leak? There wasnt one?

[fouramdesigns]

None I could see, I tightened all the bolts. I can recheck. It did fine on my recent trip till I got here, and then the problem began. It's irking me, tonight's the Music City Desmo Owners Club meet up, and my bike is sick, so I'm missing out again.

[fouramdesigns]

Called the shop to schedule my appointment, said it would be Thursday/Friday before it's done, and he's not so sure that the CO/enrichment may be the issue. This is the shop manager, I had originally talked with the head mechanic. Where is the spark plug located, and what socket/tool will I need? I hate to be without my bike that long, the days have been gorgeous. What else am I missing here? The damn thing was purring till the day after my trip up here. I wondered if it may be ethanol since most gas stations are now including it. I'd love to give this a shot myself. With it being fuel injected, what adjustments can I make?

[Jobu]

Called the shop to schedule my appointment, said it would be Thursday/Friday before it's done, and he's not so sure that the CO/enrichment may be the issue. This is the shop manager, I had originally talked with the head mechanic. Where is the spark plug located, and what socket/tool will I need? I hate to be without my bike that long, the days have been gorgeous. What else am I missing here? The damn thing was purring till the day after my trip up here. I wondered if it may be ethanol since most gas stations are now including it. I'd love to give this a shot myself. With it being fuel injected, what adjustments can I make?

The spark plugs are located in the top of the cylinder heads.  On the S4 models, the coil plugs directly onto the spark plug.  You'll need a long extension to reach down into the spark plug hole.

Being fuel injected, there isn't much you can do to it other than look for exhaust/intake leaks and other reasons why it would have suddenly changed mixture/tuning.