Bonneville America Forums Forums Technical Forums General Tech how does the air box blow up?

i was looking at the photo and i see some had the air box explode or does it enplode?

it EX-plodes in many,many peices!!!...this is usually caused by cracking the throtle just a bit before trying to start it, causing a catostrophic back fire ...a totally un-nessasary move...just pull the choke (fule enricher) and push the start button....leave your hand off the damm throtle.....ask me how I know!!

I remember reading somewhere,long time ago, that if you pull out the choke too much (ie: over half way) and crack the throttle on startup, it can/has happened.

Yes you do feel it.......

I'm still feeling it 30 hours later....

And I thought I was the only one with this problem.

Some people......

No really (I'm thinking how to word this carefully....) The airbox on my bike exploded yesterday.

This has to be a joke, with all the other things I have to worry about now I have to worry my airbox is going blow. What ever happened to the days when you just started her up and went for ride.

Not only do we have cagers after us Triumph enginneered a bomb just two inches from our "family jewels".

Please tell me this just a joke.

Quote:

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Yes you do feel it.......

I'm still feeling it 30 hours later....

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So i guess GinaS is never going to Heaven

Heaven sounds boring...and I can't play the harp!

my bike has been in twice due to the air box explodeing!! infact this time they have had it for over 2 weeks. the 1st time they said it was due to the ignighter unit failing, this time it was due to a blocked pipe from the emissions chamber?? both times i started the bike as i always do. choke on, clutch lever in, no throttle. press starter then...BANG!!. no air box, big flame and a 50 mile ride to the dealers!, ive had the loan bike for just over 2 weeks and now ive clocked up 800 miles on it, (basic bonnie). ive had a list as long as your arm of things going wrong with the bike, and its only 6mth old. if it wasnt for the fact that the dealers have been so good id be well pisd off by now.at least the 3 loan bikes ive had off them have been ok,if it wasnt for them my bike would have an extra 1500- 2000 miles on it.

I'm looking at getting "my" Thruxton back....

Thruxtongirl maybe riding again!

Gina you can always borrow my OE STD pipes to go to the dealer with

Don't think I'll get up there and back by 11am...

If you leave the bike in neutral, you can start it while standing next to it and then you won't blow up your hoo-haa.

Kinda like this:

This may be an incredibly dumb question for the Brits, but are the noise and exhaust pollution standards so high that ya'll can't "Freak"? When I freaked, I consigned my airbox to the heap, and it's been there for over two years. I don't think I'd have near the patience that 'Smith' has had with more than one box going out, I'da just finished the job and put K&N's on. Just curious.

dog, you may not know Gina was actually Gino before the air box blew up.

Mine too. Dremel and a cutoff wheel make quick work of it

Is a drilled airbox less likely to 'splode?

I was fortunate enough to have changed over to the Freak before experiencing this, but it would seem logical that drilling some good sized holes in the airbox would release the energy/pressure rather than blowing the thing up. It would also theoretically provide more intake air as well.

Here's the thing, all the 'sploded boxes I have seen were cracked on the carb side of that baffle plate in there, which leads me to believe that it is the air filter that is not releasing enough pressure fast enough and it blows up. So while I agree that more holes = more chance for pressure relase, it doesn't seem to happen that way.

OK someone with a drilled airbox go crack the throttle on startup so we can test the theory out

This same thing used to be a big problem with Air-Cooled Porsche 911's with the Continuous Injection System (CIS) Because the cars were programmed lean for emissions purposes, they were already predisposed towards Lean Backfires through the airbox. Add in starting on a cold day, where the A/F goes even leaner, and they'd have a big problem with lean back-fires blowing out the airbox. They (Porsche) eventually installed a pop-off valve into the airbox to act as pressure relief, rather than correctly re-program the CIS to add in more fuel.

well i don't know gina but i don't want to become thomasina so i think i going to do my own mod th the air box, has anyone done this with out buying the Freak, it seem that you can do this mod for a little less, i have the jets just got to get the filters.

I had an airbox blow up over a year ago and I've had a few really noticeable backfires. The ones I remember all happened at gas stations or fast food places when I had shut down the bike for just a few minutes and then restarted it. Cold startups have never been a problem. I drilled a 2 inch hole in the bottom of the airbox and filter, removed the snorkel and put in a K&N filter that is freer flowing than stock so the over pressure from the back fire can be more easily dissipated. It doesn’t stop backfires but it keeps them from cracking the airbox. Oh, it makes the bike run a lot better too

my bike is only 6mth old and on to its 2nd airbox, on both occasions i have started the bike as i always do, pull the choke out, clutch lever in, no throttle press the starter and BANG!,ive been on a loan bike for 3 weeks now while the dealer has been trying to sort it, and to try and get triumph to replace my bike as to-date ive had new front brake disc and pads, new side stand, new speedo cable holder, new rear wheel and a few new bolts that have fell out. triumph have said i have no grounds for wanting a replacement bike, as all the problems have been rectified under warrenty. but i think im entitled to some sort of compensation as my dealer is 50 miles away and every time i have to take the bike in im loosing time at work, and time on my bike!, im just glad the dealers have been so understanding and helpful,i can recomend them to anyone in the area of york(uk).a1 moto, theyre a great bunch, pitty the factory arnt as understanding.

Usually starts with a little fuel getting into the box. Maybe the rider forgot to shut off the petcock, maybe a sticky float, somehow fuel gets in there.
Then, a twist of the throttle at just the right time while starting the engine leans out the mixture enough (or it is just naturally too lean) to get a carb backfire. This touches off the gas vapors in the airbox and you suddenly get bits of hard black plastic all over the place.

Good thing the rider is protected by the seat and side covers! Otherwise Triumph would definantly have a problem on their hands with liability.....

Also if this ever happens you would be advised to shut the engine down straight away otherwise at full throttle you could suck something straight into your cylinder couldn't you?