SCROLL DOWN for pictures of the spark plugs...



So I took off from first today, and missed second, instead i shifted to neutral and went wide open throttle, as soon as i realized i ofcourse let off, im pretty sure it went passed redline.

Now the bike runs kinda crappy, I felt the exhaust pipes, and it seems the second one (if you're looking down, 2nd from left), doesnt get hot, i dont think the 2nd plug is sparking anymore. Could I have hurt something mechanical overeving? i'm hoping i just need a new sparkplug.


What do you guys think? help!


edit- update

I pulled the plugs and they looked OK, so i put them back in. I burnt my hand on every exhaust pipe, so they're all firing .

The bike sounds and runs ok, except it backfires like crazy when i let off. for example, i'll be in 2nd gear, reving slowly or fast, up to 7k, and when i let off it gurgles a little bit, then itll pop pretty good, and shoot out a blue flame. it'll do this almost every time i let off from 6k + and let it engine break.

as far as i know, the carbs are stock, and so is everything except i put a 2.25" straight through muffler on it.


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The bikes are built to take a fair amount of abuse. Revving isn't too great for it, and unless there was something that was already weak... it shouldn't have just broke.

Interms of just losing spark to ONE cylinder.... That to me is even more unrelated to "over-revving"

 

You could of gotten a fouled plug, or if you have never replaced them they could just be old as hell. Either way pull the plugs and check them out.

 

I'm hoping the over-rev didn't break anything. I wish there was a rev limiter .

I don't think it went to far into redline, but who knows, I try not to stare down at my tach too much when getting on it. I try to look straight (i ofcourse glance down a little bit), but sh*t happens.

What's the easiest way to change the plugs, from the side (pull 2 out from each side) or pull the gas tank and go from the top?

also which plugs should I replace them with? what should they be gapped to?

 

You can go in from the sides, it is not necessary to remove the gas tank. I am running NGK Iridium DPR8EA-9. I don't remember what they are gapped to, you can check the service manual on that.

 

I pulled the plugs and they looked OK, so i put them back in. I burnt my hand on every exhaust pipe, so they're all firing .

The bike sounds and runs ok, except it backfires like crazy when i let off. for example, i'll be in 2nd gear, reving slowly or fast, up to 7k, and when i let off it gurgles a little bit, then itll pop pretty good, and shoot out a blue flame. it'll do this almost every time i let off from 6k + and let it engine break.

as far as i know, the carbs are stock, and so is everything except i put a 2.25" straight through muffler on it.
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bump, anyone else backfiring / throwing flames? am i just running rich? is something wrong?
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I thought there was a rev limiter...because I ,too, have missed 2nd and revved the crap out of it and could have sworn that it only will rev so high... anyone else? Also according to the troubleshooting section( since I have never had this problem myself ), try checking ignition timing, valve clearance, valve timing, valve spring tension, fuel delivery( fuel pump can be a turd) or take it in for a tune up ( this should check/ adjust most of these ). Good luck!
Keep us updated!

 

i'm starting to think that it's running lean. I know there is a big exhaust leak right before the muffler, and the muffler is 2.25" straight through.

maybe the muffler on it is not restrictive enough, and isn't causing it to have enough backpressure.
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I'd fix the muffler leak, change the plugs and check your compression - you may have bent a valve.....hope not[X(][X(]