What would eventually happen if a motorcycle was over-revved continuously.....?

Question

i saw some clips on youtube of engines with smoke coming out, is that the most that would happen though? or would it burst into flames/sparks, and explode and stuff.

give me a blow-by-blow if you like, or just get straight to the point.

it's interested me since i was a kid, what would/could happen, i don't know why though.

Answer 1

Ungoverned revving to beyond maximum will result in catastrophic engine failure and seizure

Answer 2

I would go along with any other answers you receive,BUT, I think with modern day lubricants and close engineering tolerances, my answer would be not a lot. Sure, if it was run flat out for several hours it would get awful hot and the oil may cook, then it would eventually seize up.In normal running a well maintained engine would not suffer badly .

Answer 3

Popeyes answer is exactly what would happen and how it would happen.  

To popeye= Ha nice job thinking fast enough to hit the clutch so you didnt eat the pavement.

Answer 4

err yes it would blow up holled pistons bent valves you name it get ur wallet out. most bikes have rev limmiters there cool as u can pull into the ignition cut out then change gear but with out load on the engine eg in gear and moving then its bad for the engine and persistant use of over revving will feck it up depends on how strong ur motor is really. william.

Answer 5

B A N G !!

All over

Answer 6

Critical moving parts would experience oil starvation and seize.

Parts could get so hot that they melt apart and snap.

I've seen bikes throw connecting rods through the bottom of the crankcase.

I've seen camshafts get so hot and burnt, they seize and weld themselves to the head and cam cap journals.

Answer 7

As long as you kept it under the redline, nothing.

Answer 8

There's a number of things that can happen ranging from shortened engine life to sudden death.  Long term high engine speed wears piston rings faster than normal.  To high rpm can cause valve float and a piston can hit a valve that's still open when it should be closed.  Or the valve can slam shut like a screen door and pop the head of the valve off, also not good.  Overheated oil can cause bearing failure or galled pistons and scored cylinder walls.  There are countless ways to ruin an engine, so it's hard to give specific ways.  Oh, no it won't burst into flames unless there's a fuel leak.

Answer 9

Go buy a cheap old use junker and tape the throttle open and find out. Just in case stand behind a wall. It sounds kinda fun in a demented sortof way.

Answer 10

Catastrophic failure.

I ran my CBR flat out for about 100 miles on country lanes. One of the pistons ended up outside of the cylinder head after the head disintegrated due to a massive internal failure. I believe that the timing chain failed first because the small end had been destroyed, the con-rod was in two pieces and valves had met pistons. Having a rear-end lock up at 120+ mph knackers the rear tyre a bit quick, leaves a lovely darkie, gives you an instantaneous massive high from adrenaline and fear and surprises you at how quickly you can grab the clutch! I am just glad that I was going in a straight line at that time or else I would not be answering this question.

BIg praise to Honda though because the clutch, gearbox and chain survived intact. I replaced the chain anyway (as well as the engine!).

Answer 11

Went to a rally one time and as you do, someone brought a 175  Honda benly along for just this purpose. Having emptied it of oil first it was started and the throttle pinned back. after a while the exhaust started to glow red but it kept going for nearly 4 hours before it finally seized solid. not sure why this was so enthralling, but it was. Us bikers must have a darker side when it comes down to it.

Answer 12

i think it might blow up, my little brother was reving my dads bike up and he stopped him, i think it damages the bike