"Different" Backfiring problem on Vaquero

[Godfather]

I think it's different anyway. This has only happened about 3 times in the 2,500 miles i've had my bike. Out riding, coming up on a stop. Throttle closed, normal decell. As the engine reaches about idle speed there is a LOUD pop,. pop ,pop and the idle starts to drop. I give a little gas and the bike shuts off. When I try to start it takes a few seconds of hitting the starter before it fires and starts.
Guess it would help to know my setup. V&H 2:1 pro pipe with quiet baffle and wrapped header pipes, BAK, Power Commander V with Auto tune. Thunder gasket in intake, pipe joint sealed good.
Also before adding autotune it back fired thru the intake a few times, don't know if that could mess anything up or not.
Since I added the auto tune it's done this once. The other two times were same setup w/o the auto tune. Oh, and running about 90 octaine fuel.
It still has some of the normal decell backfire, altho the autotune has stopped a lot of it.

As it sits now it pulls strong all thru power band, getting about 36 mpg around town driving. Temp indicator stays about mid mark.

Any thoughts? Anything to be worried about?

[gcsteve]

Sorry, I don't have an answer for as to why. But, I figure I would let you know that same thing happened to me recently. I thought it was a pop from airbox. I was able to keep it from stalling by hitting gas a few times. I have thunder airkit v&h pcv.

[DHACK666]

Hi New to the forum.
Hope this helps. I had the same issue after my first oil change. Dealer was no help so I searched it on the web. I found a guy having the same issue and he had it in a shop for something else and the mechanic noticed it. Asked if he wanted him to look into it.

What he found was too much oil and it was getting pushed into the air filter but also causing pressure in the transmission. Not sure about this but I checked my air filter and I had oil as well. I know I put more oil then recommended but I could not get it to register on the dipstick with the recommended amount in the manual. I have since cleaned the filter and put only the amount recommended and it registers on the dipstick when the bike is on the side stand. This has almost completely stopped the backfiring. I only get it once in a while whereas I would get it at almost every stop.

[Blakjack]

Could it have been a bad batch of fuel?

[garvulcan1700]

So how much oil did you put in to fix the problem? 4.5 or 5 quarts?

Originally Posted by DHACK666

Hi New to the forum.
Hope this helps. I had the same issue after my first oil change. Dealer was no help so I searched it on the web. I found a guy having the same issue and he had it in a shop for something else and the mechanic noticed it. Asked if he wanted him to look into it.

What he found was too much oil and it was getting pushed into the air filter but also causing pressure in the transmission. Not sure about this but I checked my air filter and I had oil as well. I know I put more oil then recommended but I could not get it to register on the dipstick with the recommended amount in the manual. I have since cleaned the filter and put only the amount recommended and it registers on the dipstick when the bike is on the side stand. This has almost completely stopped the backfiring. I only get it once in a while whereas I would get it at almost every stop.

[DHACK666]

From the manual............

4.1 L (4.3 US qt) (when filter is not
removed)
4.3 L (4.5 US qt) (when filter is removed)
5.0 L (5.3 US qt) (when engine is
completely dry)

I put about 4.5 L , it barely shows on the dip stick when straight up (Vert.)
but when on the side stand it reads within the mark. I ran it most of last summer and haven't added any this year.

Did you have oil in your air filter? Mine was wet with a puddle of oil in the corner.

[garvulcan1700]

No, no problems. I want to avoid any problems that's why I was asking. I just did an oil change and found that I had to add a full 5 quarts to be within the middle range on level ground and level bike and warm engine. So when you where having problems how much oil was in your engine?

[DHACK666]

LOL 5 L .
I used all 5 litres of oil the first time. I followed the manual, let it run let it sit and it still showed low so I added the rest of the bottle. Didn't have any issues for about a week, then it started backfiring and the dealer had no idea. They raised the idle speed but that didn't work and I didn't like it. So I searched on the web and others had reported the same issues as far as the amount of oil.

[DHACK666]

It won't take long to get oil in the air filter compartment if you over fill it. Just keep and eye on it. Better to be safe then sorry.

[garvulcan1700]

Originally Posted by DHACK666

It won't take long to get oil in the air filter compartment if you over fill it. Just keep and eye on it. Better to be safe then sorry.

Just an update, I haven't had any issues yet with filling it up to 5.0 Qrts. to get it to read in the fill marks. I've rode just over 800 miles since the oil change. I will still keep an eye on it.