Banshee Backfires At Wot

[duketj8]

I have an 87 banshee that starts and runs good until wot then it bogs and backfires. I have cleaned the carbs and rejeted the mains fro 210, 230, 250, 270. It runs the same with any jet. It is just set up with fmf pipes and a uni filter and 32:1 mix. I have tested the stator and the readings are right in the middle of where they should be. Could the stator still be bad? Any help would be great.

Thanks,

Greg

[H300F]

i would go up higher on the mains, you might need to hit about 320s. if that doesnt do it i would then look at the plugs caps and wires, coil,

[shortbus]

what do the plugs look like after a WOT plug chop?

[duketj8]

My primary coil resistance jumps from .5 to .4 ohms which is a little high but close enough to .38. My secondary resistance doesnt measure at all so I am thinking that my coil is bad. I am pretty sure I was measuring right I just put one of the probes in the sparkplug boot touching metal of course and the other where the black lead would be connected on the coil. If anyone knows if this is what a bad coil looks like please let me know.

Thanks,

Greg

[MotulMonsta]

One lead is a ground and that won't have any resistance.. the orange wire is the hot wire...that's where you sould get a reading. Both plugwires should read the same seeing as they are part of the same circut. If you have a diffrent reading between the two plug wires..your coil is bad..if that diffrence is minor like .1 ohm..it should still be o.k...but of it like 3 or 4 you should test out a new one. Now your stator is another story...I don't know the test requirements off hand but you can get them in a good shop manual like Clymer for the banshee.

[duketj8]

In my yamaha manual it says to take the reading from where the black wire comes off to the spark plug lead. I checked it that way and got nothing. I also checked it from where the orange lead to the spark plug lead and got nothing. I did check my stator and it is within factory specs. I just want to know if since I didnt get a reading do you think my coil is bad?