[pwsaunders]

Hey everyone.  This is my first "real" post.  My others have mainly been to ask component compatibility and the such.

Background, I was in Buffalo NY, but took a contractor job with the USAF in Germany.  I am an AF Vet, and had been stationed at the same base when I was in so I had to jump on the opportunity to come back.

Well, two Monday's ago my 2010 Military showed up in all her glory, and barely hanging on with one strap in the crate the moving company shipped her in.  Luckily no breakage.  She's been running fine, other than a minor issue with too much oil being in.  I put in about 2 quarts, as per the advice of CMW (my manuals are still boxed up in my household goods).  I guess that was a bit too much.  Had the overflow into the air filter box.  Twice now.  I feel that even moderate speeds 60 to 65 on the autobahn make her want to vomit oil.   So I bleed off twice, and am hoping this does the trick. Seems to be something that happens, according to other posts I have read.

The real excitment was yesterday when I started her up after leaving her in the driveway for a few hours.  I thought it just backfired, until I heard the whomp whomp whomp of an open air filter box.  Low and behold as I look down, open door, and shattered lock components on the ground.  Anyone ever heard of a backfire out the air intake??

-Patrick

added:
when i was trying to take the nut off to get the filter out to clean the box, the damn thing with bolt twisted and snapped off the bracket!

[Andy]

Yes, that's my airbox in the photo...

[barenekd]

Technically, a backfire is out the intake. Has been known to blow the entire intake manifold off! Commonly done with too much ignition advance and a flooded cylinder or intake manifold. It's very common in old radial aircraft engines as the bottom cylinders are easily flooded. If it's blowing out the exhaust, the proper term is afterfire, generally caused by a lean condition as the throttle is shut off. The lean condition causes slower burning of the mixture in the cylinder which allows the still burning mixture to go out the exhaust and explode any raw mixture still in the tailpipe. Has been known to blown the entire exhaust assembly off. If you are hearing just a light poppity-pop-pop at idle, it's just the excess fuel burning past the valve from the aforementioned lean idle mixture. Might wanna richen the mixture a bit as this can burn the exhaust valve.
Bare

[mbevo1]

The real excitment was yesterday when I started her up after leaving her in the driveway for a few hours.  I thought it just backfired, until I heard the whomp whomp whomp of an open air filter box.  

Backfires are not uncommon with the carb models if the mixture or timing is off -  particularly with points ignition.  I've blown the carb off on my iron-lung a time or two...

If your UCE is doing it - something is wrong IMHO.  EFI and electronic ignition and auto-decompressor should make sure it doesn't happen.

Mike and S&S in Michigan

[2bikebill]

I get a few good ripe bangs out of the exhaust since I fitted the Goldie, but nothing out of the airbox. Wants looking at methinks.....

[perri]

I own a 2009 C5, in two years, two broken lock,
due to return air, clean the spark plug often

[gashousegorilla]

 I think it is just the lock assembly , where the flat catch attaches to the back of the lock assembly. It's attached to some week pot metal and it just snaps, vibration? change in air pressure in the box?  Mine blew off on the Highway. Make sure all the parts are accounted for, and nothing got sucked in. I fixed mine with a few self drilling/ tapping screws around the edge of the lid.Dabbed the heads in touch up paint.

[Ducati Scotty]

I wonder if the airbox retorfit would help to keep this from happening.  Now you guys have me scared that pieces are just going to blow right off the bike while I'm riding.

Scott

[GreenMachine]

exploding enfield..love it....u guys are nuts..

[r80rt]

'09 C5,10257 miles, never seen anything like that.

[gashousegorilla]

 I'm pretty sure ScooterBob posted an improved latch he found....Not long ago.
The new latch and r80rt's.....sorry Shapper's air pod upgrade Might be the way to go.

[prof_stack]

Actually, having an opening where the lock used to be might be a good way to get more air in the box.  Use black tape to seal the box lid (this works best on superior colored C5's.   )

Or just yank out the whole box and use Shapper's (or is it modest r80rt?) mod with a large cone air filter.

[r80rt]

I'd love to take credit for that mod it's a good one, but my Ma would slap me upside the head for lying

[SSR]

@pwsaunders- Whats your odo mileage and when was your last service done. Is your bike manufactured june  or after 2010?

[pwsaunders]

Just rolled over 1000 miles this week.  Bought it in Sept 2010, so I'm guessing it's manufacture date is prior to June 2010.  Had last service in November, around the 600 mile mark.  Put it in storage for the winter and prepped it for shipping that occured in April.  Just got her going. 

@Prof, the lock is still there, just the tang that engaged the little nub to secure the lock blew off when the door popped.

@Ducati,  the air box mod is on it's way.

another question, could engine oil residue fumes ignite?  I'm still figuring all the "what ifs" to see what could have happened....  she's running fine post blast though.

how many folks have redirected the oil overflow line?