Backfiring through intake

[cb750]

The other day I bought gas and no sooner than I had gotten back on the road and it wouldn't run worth a ****. Now that its home I got some codes, 13,16, 21, 36, and 47. I've got the airbox off and when it runs it backfires through the intake. The goofy thing is, it ran fine until I filled the tank.

What should I look at besides this stuff to cure what ails me?

[Kid1620]

What year is your bike

[BKKBuell]

Drain the gas and get 95 octan... U might got poor gas or even worth.. diesel in the gas... This is bad bad for ur engine, the backfire is then only a side effect

[jdline]

I got the same thing.
it dusnt happen alot but some time it dus it.

It isnt really a backfire as mor a very low en "duf"
(dont know how to say it in english) (sounds lik) Puhhh..

Not ?

[Kid1620]

Okay this is directly from EBR.
If the spray pattern of the injector is not real clean it might do that. Â*'03-04 984s did not have the great targeting of the '05+ XB9 and all XB12s

The '03-04 XB9 spray hit that little hump in the intake port and you would occasionally get fuel puddling there, especially on decel.

Before I did anything else I'd just run a couple tanks of injector cleaner through it.

Also if you do run injector cleaner don't used the hole bottle. If you used to much your bike will run like absolute crap for that tank but after that tank it should be okay. I made that mistake didn't use a hole bottle but put to much in. I could be a full throttle and it would be slowing down then all of a sudden boom it's at full power. That was a fun ride.

[unionthug]

Clear the codes and reset the throttle position setting I bet it will be fine.

UT

[anrkizm95]

sounds like a voltage problem

[jakestolar]

The '03-04 XB9 spray hit that little hump in the intake port and you would occasionally get fuel puddling there, especially on decel.

So that being said, Could someone who owns one of these buells take a dremil and polish the intake?

[cb750]

It's an '08 XB12

When I say backfiring through the intake, I mean so much that it won't run AT ALL. So, a couple tanks of injector cleaner is not an option.

I siphoned out as much fuel as I could and poured in some gas from a different station with no change.

With the airbox off there are flames in the throttle body when it does this.

The fuel pump does not sound the same when you turn the key on. It used to be faintly audible, now I have to really listen and feel to know it's running when the key is turned on.

With the airbox off I can hear a faint hiss from the intake. I don't know if it is fuel leaking or air from a cylinder. I think it is air because if I pour a little fuel in the intake it will cough at first but run somewhat ok for a second or two before dying.

I tried plugging in a different ecm with no change.

I would hate for it to be internal, but if it is what can you do, other than go big bore while you are in there? :D

[cb750]

Also, it has done this once before, same gas station. The first time it ran enough that I was able to get to work, but at 15-20 mph in first or second gear. When I came out from work it ran bad but cleared up pretty quickly. I've bought gas from that same station before for the bike as well as my car and truck with no issues. This time I had to push it a mile or so to work and get a ride home.

All the people who passed me, only one stopped. One guy on a HD passed me on the drive from the front of the building to the back lot passed, then when I got to the parking lot he asked if it was gas or ignition, like I'm able to diagnose it in the dark with no tools. What a maroon.

[anrkizm95]

like I'm able to diagnose it in the dark with no tools. What a maroon.
so the one guy that stops is a maroon.its pretty easy to tell the difference between a fuel or ignition even in the dark.
do you still have the codes or have you fixed those?

[anrkizm95]

if you still have the codes you should take care of those first.
16 Battery voltage
36 fan voltage
47 aux power outlets driver circuit
there is a good chance that what ever is causing these voltage codes is causing your other problems.like low voltage to pcm,cam sensor and fuel pump.unless these codes were caused by running down the battery.what do the plugs look like.have you tried spraying carb spray in the t/b to see if it starts and runs better assuming the plugs are good.

[cb750]

so the one guy that stops is a maroon.its pretty easy to tell the difference between a fuel or ignition even in the dark.
do you still have the codes or have you fixed those?

No, the guy who stopped offered to try to push me by putting his foot on my peg and riding. I didn't want to break a peg so I declined. The guy who asked about spark or fuel rode by me without a second glance.

[cb750]

if you still have the codes you should take care of those first.
16 Battery voltage
36 fan voltage
47 aux power outlets driver circuit
there is a good chance that what ever is causing these voltage codes is causing your other problems.like low voltage to pcm,cam sensor and fuel pump.unless these codes were caused by running down the battery.what do the plugs look like.have you tried spraying carb spray in the t/b to see if it starts and runs better assuming the plugs are good.

I've put gas in the intake as posted, but not any carb spray. I haven't pulled the plugs yet, they look like a bear to get to. The codes could have been set by running down the battery. I've got a charger on the bike now, I'll have to clear the codes and see what comes back.

[anrkizm95]

plugs are real easy to do.pouring gas in usally just floods it out.if the plugs are good try the carb spray if it runs on carb spray its fuel if it dosnt its ignition when checking the plugs check the coil connections you might also want to check the cam sensor and wires.

[cb750]

I checked my plugs and they were a little wet, probably from me dumping fuel down the intake. I pulled my fuel line off and I have plenty of flow, but I don't have the right tools to check the pressure. I changed ecms and got codes 11, 15, 36, and 44. I'm wondering about the 5v reference, where that is so I can check it. I checked my battery voltage before anything else and was over 13 volts. The low volts code probably happened when I wore down the battery.

[cb750]

I checked my plugs and they were a little wet, probably from me dumping fuel down the intake. I pulled my fuel line off and I have plenty of flow, but I don't have the right tools to check the pressure. I changed ecms and got codes 11, 15, 36, and 44. I'm wondering about the 5v reference, where that is so I can check it. I checked my battery voltage before anything else and was over 13 volts. The low volts code probably happened when I wore down the battery.

[anrkizm95]

autozone has loaner tools the fittings on our bikes is the same as ford.fuel pressure should be 50 psi

[cb750]

I didn't think bad gas would cause it to pop and fart through the intake, but when I drained it it looked like pee. I dumped in about a half gallon and flushed out the fuel line and it runs again, I'm going to put more gas in and go for a ride.