Kill Switch while riding makes a BANG from exhaust?!?!?

Question

how exactly does it work? aqnd does it harm the engine or exhaust what so ever??
thanks best answer will be chosen tonight!!

Answer 1

It just builds up the gas, then burns it off in one spark.

Its not really that big or clever, but I do admit to doing it a few times myself when cars have got too close to me in a traffic jam!

Answer 2

When you depress the kill switch, the engine is still turning full speed, that lets a good bit of unburned gasoline flow through, and into the exhaust system. Finger off switch, engine fires again, hot exhaust gas ignites the mixture in the exhaust system, hence - a big bang. Do not think it would harm the engine, but can do a lot of damage to the exhaust system. Have seen it done on cars, and burst the muffler, or on an old car, rupture the exhaust header pipe. Not so likely on a bike, but can still happen, depends on type and age of muffler. Size of bike engine also will influence the possible damage. Really not something I would recommend.

Tomcotexas

Answer 3

Think of your engine as big air pump. When a carburated engine is cruising along it is mixing air and fuel near an optimal 14.7 : 1 mixture. In normal operation the fuel/air mixture enters the cylinder, is compressed, ignited, then pushed out as spent gasses into the exhaust pipe / muffler. When the kill switch is used, and the spark is turned off, several charges of unburned fuel /air vapor mix are pumped through the engine and stored inside the pipe and muffler system. When you turn the switch back on combustion first occurs in the cylinder, then the heated gasses (fire) are pushed through the opening exhaust valve into the exhaust system igniting the unburned fuel / air mixture ---- BANG. This can result in ruptured mufflers and other exhaust system damage, not necessarily damage to engine as the internal combustion pressures are greater. In fuel injected engines both spark and fuel would be turned off, so it would be less likely happen.

Answer 4

I imagine you get the bang when turning the kill switch back on rather than off. The bang comes from igniting unburned gas while to ignition is off. Yes you can harm things. Main thing is the potential to blow your muffler apart. If you have high enough compression ther is at least some chance of blowing your exhaust valves. That could get extra nasty if the pieces scrape thew cylinder walls. To some degree you would rish destroying your engine. I really reccommend you quit doing that.

Answer 5

Shutting off the engine and coasting still allows fuel to go right through on carbureted vehicles and collect in the exhaust....when you turn the car back on, the fuel is sparked and explodes in the exhaust. We use to call them "key bombs" back in the 70's...blew out a couple mufflers that way....doing it under a bridge is really loud. It's not good for car's exhaust and cat converter as well. Not sure if it harms the engine but I imagine it's not good.

Answer 6

its not big an its not clever , but it scares the **** out of car drivers in the tunnels,
when you turn kill switch of fuel is not ignited it over flows into exhaust ,when you flick it back on it all ignites & goes bang & it can blast your exhaust seen it happen but then the exhaust was not in good nick

Answer 7

You won't damage the valves or anything but if the bangs are powerful enough, you'll cause ridges on the mufflers where the baffles attach. With shiny chrome they show up rather well, at least they did on mine.

Answer 8

Yah in my mispent youth it was considered a bit of a laugh to pull up next to a mate at motorway speeds, reach across and and tap their kill switch... if they switch back on too fast BANG..

My word we were stupid.

Answer 9

It's only funny until you blow out your muffler.