It seems to run ok up to about 3/4 throttle where it cuts out and sounds like it's backfiring. At this point, it stops pulling, just kinda flattens out. Power is normal up to that point. This happens in every gear, but of course it's more apparent in the lower gears.

I pulled the plug and it looked normal..tan colored. I didn't get a chance to replace the plug or do anything else yet. Just wanted to see if anyone had any ideas...

 

The first thing I would do regardless of how the plug looks is replace it.

 

how's the air filter look is it clean and re oiled
is the carb clean on it
did this just start to happen
does it run better if you pull on the choke
the last thing to check is to see if the rubber under the tank by the intake snokel is not floding up and covering the intake snorkel (yes this can happen I hade one that did just that, that was interesting to find)
oh and check the vent lines fuel tank and carb
good luck

 

Bike ran fine when I took it out prior to that, probably about a month earlier. Air filter was clean and oiled. It runs worse when you pull the choke, as expected.

I will replace the plug and check the snorkel this weekend maybe. Problem is the bike isn't stored at my house so I don't get alot of time to work on it.

 

you might not be getting enought gas into the engin and it is backfireing because of that. when i got my pipe on my quad before i jetted it, it was doing the same thing. after it was jetted the sound went away and the power was increased.