I was riding in a wooden area near my house and I has to cros a creek with a bout 1 foot of water deep. I got stuck in the creek and I was battleing my way out of it and I got out after a min or so. Sortly after I was climbing a hill and my bike was running kinda funny so I stopped in the middle of the hill and my banshee started to IDLE REAL HIGH so I decided to shut it off but that's the worst part when I turn the IGNITION TO OFF THE ENGINE WAS STILL REVING so I used the kill switch still reving on it's on I HAD TO STALL IT BY DUMPING THE CLUTCH TO STOP THE ENGINE FROM REVING ??????? WTF IS GOING ON IN THERE ???? I EVEN PULLED THE SPARK PLUS WIRES OFF AND THE BIKE WAS STILL REVING ????

HOW DOES AND ENGINE RUN WITH NO SPARK ????????

 

man that is funny[img]i/expressions/face-icon-small-happy.gif[/img]
I would guess that the air fuel mixture was just rite for the compression to ignite it like a diesel, but who knows, have you considerad an exersissum

 

I fixed the problem....

My godfather is a priest and he poured some holy water on the cylinder head [img]i/expressions/face-icon-small-happy.gif[/img]


Seriously I just went for a ride and my banshee runs like a charm.... probably all that humidity... who knows ?!?!?

 

I just asked my dad(who is an automotive repair technician) about it and he said if the engine got really,really, super hot, the engine heat could ignite the fuel and keep the engine running. [img]i/expressions/face-icon-small-cool.gif[/img]

 

I had the same problem with my jet ski (2 stroke also) after I rebuilt it. I was trying it out for the first time and it did the exact same thing. It just kept on going after I pushed the stop button. Then I pulled the plug wires. Same thing. Then to finally get it to stop, I had to shove a rag into the carb to choke out all the air!!

The problem turned out to be a phenomenon called "lean engine run on" and what was causing it was an intake leak at the carb base. I had made a carb support that bolted to the cylinder head and it didn't quite match up until I tightened the bolts. Well guess what? When I did that it put just enough side pull on the carb to cause a leak and then that is where the air was coming from, leaning it out and causing it to basically just free spin and ignite without any spark. The guy who told me about it said it doesn't make any horsepower at all (or not much) even though it is spinning at high rpm so it won't run away in the water but with no load on it-there she goes!

Sounds like you have an intake leak, or at least had one at that point for some reason. Check all the intake and carb connections just to be sure. It sure does freak you out though, doesn't it!!

 

My banshee has got some boyesen reed valves so maybe I should check to see if the boots were bolted on the right way after being installed...

 

my old e-ton sierra 90 did that every time the chain popped off. It sounded like it was revving at full throttle and turning the key off and ignition button off did nothing, even pulling the spark plug out like you did didnt stop it. The only thing I could do was turn the fuel off and after 5 minutes or so the engine finally slowly died. It happened twice, from the sounds of it its a 2-stroke thing.

 

Yea. Couldn't hurt to go over everything. Try spraying some WD-40 or carb cleaner around the junctions when its running and if that causes it to sputter or anything, you've found the leak. Patch it up and go ride!
Good luck.

 

HEY...THIS SAME THING HAPPEND TO MY BLASTER.....WHAT HAPPEND WAS THAT MY GRANDPA WAS RUNNING IT IN THE FEILD AND HE WAS ONLY USING FIRST GEAR....IT GOT THE SPARK PLUG GLOWING AND SO IT KEEP SPARKING ECEN THOUGH THE WIRES WERE OFF. AND THE REASON WHY IT WAS REVING IS CAUSE THE THROTLE CABLE WAS STUCK

 

My brother-in-law has a 250 Odyssey that did that one day while we were riding. Pulled the plug wire and kept running. We pulled the choke to kill it. I'm glad this topic came up-now we have someplace to look for a starting point. It does sound like a 2 stroke thing though huh.