Burned Air Filter?

[MAXIMAN]

Ever seen this? I pulled the air filter on Zilla as I was changing oil...getting ready for the '05 season. The outside of the filter was burned in two spots...literally to a crisp.

The inside...the carb side...was fine. No evidence of combustion. Any ideas?

[randy]

The inside of the filter is the air intake. The outside faces the carbs, so you may have experienced a few backfires in the past?

[MAXIMAN]

No you mis understood. Maybe I didn't articulate it properly.

The inside of the filter protects the carbs from the "outside" world...dust....nasties.

This DEFINTELY not backfire. As you will see in the pix. there is no burn from the carb side of the filter.

Here here...pictures to explain:

[MAXIMAN]

FREAKY...Huh?

[grabberblue]

That is weird, I don't have an idea for explination but it sure is a good thing it did not burn anything else and went out before catching everything on fire.

[MAXIMAN]

Thing is I have no idea when it happened. I replaced that filter about a week after I bought the bike (September).

Bad thing is those suckers are hard to find. The only ones available are Yammy OEM. $28 bucks each. Emgo...UNI...K&N never made replacements for the XJ11.

Oh well...

[lsippell]

air filter

Zanotti Motor Co. has them and I think their cheeper than $28.00.

Louis

[MAXIMAN]

Yep $22...thanks Louis

[DiverRay]

Cody;
Looking at the filter, I'll bet you had a fuel leak in the carbs. some of the gas or fumes got outside of the filter, or just soaked it, and then you had a small fire after a backfire.
Didn't you have problems with the carbs right after you got that machine running? Just my 35 years and $0.02.

[MAXIMAN]

No actually that was Kong we had a small fire with when we were messin around tyring to get it to run.

Zilla is the bike in question (xj11). That bike ran great fine from the day I got it. However now that you mention it...the filter did have a decided gasoline smell. But I've never caught it overflowing into the air box.

[MAXIMAN]

Somehting just occurred to me. Back in October when I took the "long trip home"http://members.aol.com/rocktone/ ...I was in the parking lot of a Cracker Barrel about to park the Maxim. I hate to admit it but when I pulled into the space at that low speed Zilla started going over with me. With all the bags and a full tank I could not stop it. It didn't hit hard...I was able to lay it down easy.

But it took about two or three minutes to get it uprighted...with the help of two Oklahoma cowboys. The carbs dumped a slug of gas into the airbox then. It took while to get the thing aired out so it would start. When I did I had to drive it a few miles before it would run right. I wonder if I soaked the AF then and sometime that day it backfired a little and caused the fire.

Hmmmmm............

[DiverRay]

Jog the old grey matter and all kinds of things fall out!!

[skids]

Like someone previously said, the inside of the filter is where the snorkle feeds intake air. The outside faces the carbs, at least on one side. It looks like you had some popping through the carbs. Were the outlets of the associated carbs blackened/burned? Do you have "dead spots" in the torque at particular rpms??? If you do, and it is due to bad pipes, etc, you can cause a condition where the carbs can't expell burned exhaust well, and it can come into the carbs... Well, at least that is what I think happened to one of mine.

[skids]

Ooops! Sorry, I take it all back. I am on the road and I didn't wait long enough for the complete pictures to download. Now I see this is not an xs11, so I know nothing about it!

Originally posted by skids
Like someone previously said, the inside of the filter is where the snorkle feeds intake air. (SNIP)

[MAXIMAN]

Skids

Sure it's an 11. I mean it has the same engine...with minor changes...but no more significant than from year to year changes in the XS series. The air intake WaS different but the rest of the engine is pretty much straight up XS11.

And yes I do have a "flat" spot in the torque...or pick up. It is really evident in the last couple gears (4 and 5) from about 6000 rpm out to redline. Power seems flat and it misses very slightly.

I never thought about the exhaust being plugged. What was up with your XS?