I dont know what to do with my 906. I have replaced the plugs, but it is loading up and backfiring like crazy. It has so little power because of this I cannot really ride it. the more throttle I give it the worse it gets. I do know that I have to charge the battery after I ride it because the charging circuit doesnt always work. So I guess I need to replace the Stator/Rectifier, or something. I really dont know where to start. It backfires a bit during Idle when I rev it up, but it at least will rev. Help? I'll get some pictures on here soon! I am slowly restoring this bike, and I do love it. But I am currently frustrated Thanks Guys

first: is it backfiring out the pipes or the carbs?

i'll assume pipes for now:

if your battery is good, the r/R will not make your bike backfire. backfiring is not a battery/power issue anyway.

you need to check:

1. ignition timing, too late and its out the rear end.

2. carbs: specifically floats, air intake etc. the issue may be too rich a mixture. this is the most common issue in my experience. check your floats- and examine your plugs for black buildup.

3. valve clearance: if you are loose, the explosive compression is going to go right out your exhaust.

also if you have the weber check the o-rings on each side of the carb that seal the idle jet assembly

Check inlet manifolds, that there are not ANY air leaks.... ....and also that headers/sylinder head gasgets are ok.

Thanks for everyone's help! It is backfiring out the pipes, especially when I try to ride it. I replaced the fuel filter and all of the fuel lines first. I will try to pull the carb off tonight and check the float, and gaskets. I have never had it off, so It cant hurt. I haven't tried messing with the valves yet, because Im not sure what Im getting into. As far as it being a timing issue, I do know that Ducati replaced some of the electronics with racing parts for a 900SS. If it is a timing problem does that mean it needs new belts? I put a 130/70/16 Continental Contrasport Front tire on it this last weekend, and am going to put the modified fender back on tonight. It looks good!

if you don`t know how old your belts are and when the last service was done you should definetely change belts and check valve clearance. I guess I would do that also before disassembling the carb. Is the carb synchronization ok?
As it was said, electrical problems are not a reason for your symptoms but they can add to that so clean all ground connections and check the voltage at the battery and coils. As you say the charging circuit doesn`t work I wonder if the coils get constant current or also only once in a while.
I guess the last belts were properly installed and all the pulley marks matched the marks on the housing when the belt was changed?!
Have you done a compression test ?

Well I bought the bike a little over a year ago, I have probably only ridden it about 200-300 miles. It ran fine then, but did drain the battery. Last summer, it started acting up. It would run fine one minute, and the next it would have no power, and backfire. Now it does it all of the time. I will check the belts. If they dont look new, I will replace them. I'll check out the condition of the valves, and electronic connections too. Thanks!

Here is a real stupid one: check to make sure your choke isn't sticking "on" due to cable misalignment etc. I only mention it because it happened once to me and its worth a quick look before you tear everything down.

and get a new r/R -> if you aren't charging then you also aren't getting the power you need at the coils- which means you get uneven/low spark at the plugs and your misfires could be building up until they backfire out the pipes.

check the yellow wires from your stator, especially the junctions to the R/r - > they often melt there.

Thanks, I will check out the wiring, and choke before I tear into the harder stuff. This is all very helpful! I will update you all when I get some results from all of this!

Ok, so I checked the Choke, and everything is ok there. I also cleaned and inspected the wiring. It was in relatively good shape, except for the plug coming from the r/R, (I believe that is what it is), (right side mounted next to the shock adjustment resevoir) has obviously been very hot, and looks brown, and bubbled like it has been way too hot! I started the bike after my cleaning and inspections, and it is doing more of the same. But I did notice that when I shut the bike off, smoke continued to come out of the right exhaust pipe for quite a while. I pulled the plug, and it is really fouled. This leads me to believe with the damaged looking plug on the r/R unit, and the spark plug, that it just isnt getting enough juice to fire correctly. Maybe I'm wrong and it is a valve issue or something too...What do you guys think? Also, I was looking at previous threads, and other Paso owners use an eletrex RR51 unit to replace the stock r/R? If this is true, I'll try to find one of those to start! I'm making some progress at least! Thanks for the helpful tips!

How are your coils?

I have had a similar problem to this and it was due to an intermittent coil failure (the engine would break down/ lose power/ backfire, above about 4500,rpm, and only when the engine was hot.) you said the plug was fouled, did you only check one plug?

If the coil diagnosis is correct (assuming it is only one of the coils that is failing) you will have one foul, and one clean spark plug.
to diagnose this, switch the coils over, and see if the situation is reversed.

the smoke coming out of the exhaust may just be unburnt fuel vapor (rising out of the hot muffler), you should be able to smell weather it is raw fuel, or burnt smoke.

then again the whole problem may be something as simple as a cracked spark plug insulator, or a bodgey lead.

hope this helps.

I do know that many of the stock components have been switched over to 900ss aftermarket parts by ducati. I am not sure if they did the same with the coils though. I did notice a small crack in the plug wire for the front cylinder. I will see if I can get my hands on some wires, and It looks like I will need to go get a voltmeter so I can test the coils. Thanks.

if you can get your hands on a digital tachometer (like the ones they use on go-karts) you can test your plug leads with that

Ok Guy! Some good news FINALLY! I talked to the Ducati tech at Letko Cycles(great shop in Kansas City). I told him what is going on, and he was the one who put all of the electronics on the bike. He told me that it sounded more like a carburator problem. So I before I took it off the bike I went and got some SEA FOAM. I hear a lot of negative things about this stuff, but just as many positives. I didnt follow the directions and let the bike warm up, but sucked it up into the fuel line, and let the bike sit for a while with it in the system. I put the tank back on, fired it up, and after some smoking...WOW, what a difference. It purred to life! It is still sputtering a bit, but night and day difference. I will swear by this stuff now. I am going to still track down the wires to the stator, and see whats going on with my r/R, and Plug wires, but I can at least take it down the road now! Thanks for everyone's input!!

SEAFoaM is great stuff, works better if you follow the directions . Do yourself a favor and buy a gasket kit,about 30 bucks.