Misfiring and backfiring

[Joshwuh]

Hey guys I need some experienced knowledge to help me diagnose an issue. Let me preface by saying that I recently changed my oil and filter and slightly overfilled my oil. I was in a hurry and didn't drain the extra oil and then forgot about it. I rode 300 miles or so and it seemed to run fine but near the end I was getting hesitations above 5k rpms until it got warmed up.

Yesterday, I didn't have the time or tools to drain the excess oil before I started my 120 mile trip home from school and figured I'd be fine just changing the plugs and doing the oil once I got home. It ran fine for 20 miles and then there was a traffic jam. After 30 minutes of stop and go traffic we got out of the jam and I started to open up my throttle but I was getting continuous misfires and backfires at 5k rpms and it wouldn't really get past 5k in 6th gear (I could go about 50mph but it backfired and misfired nonstop). I had to pull over and leave it at a gas station 100 miles from my house and will pick it up on my way back to school Monday so I need to have a good idea of what is wrong so that I can at least ride it the 25 miles back to my house at school.

My first thoughts are to go and drain some oil and put new plugs in it but this is all I can think to do. Does anyone think they can help me diagnose this so I don't have to pay to have my bike towed?

Thanks in advanced guys.

 

[drewpy]

you may have forced oil into the crank breather and hence the intake so your burning oil as well as fuel.
not really good for seals either as the extra pressure can burst those as well.

can't think of anything else unless happen-stance has some crud in the fuel line as you may not have a in-line fuel filter fitted.

 

[wildcat400]

Hi, maybe is the voltage low, generator is not able to deliver ennough, or a drop of voltage in the wiring is possible. If you rise the rpm, the ignition will drop in high voltage. If you open the throttle, the high voltage at the spark plug must increase. If you have alow voltage at primary side, the engine will hesitate or will have missfire.
I hope this my help