I'm not sure why I didn't start here, but I've gotten a few tips from the Facebook group. Maybe you all can give more advice. I should say this is my first two stroke, but I've done a fair bit of tinkering on four strokes.
My 2011 ec300 ran fine when I bought it last spring. About a month ago, I went to ride and it wouldn't start. I traced things back to an oily spark plug. I ride at 500-1500 ft above sea level and temperatures are usually between 70 and 80 (lately at least). I've got a 175 main jet. I haven't changed anything from the previous owner in the carb.
Anyways I replaced the spark plug, fired her up and went to go ride around the backyard. Rolled up to a log and tried to pop the wheel over and I about fell over there bars. With a little more testing I determined it had no top end power. It runs great at real low revs, but as soon as you open it up, it won't rev, has no power, is smoker than I remember, etc.
Someone suggested jet body gasket in there carb.
I replaced it and it still runs the same.
Someone suggested right side crank seal.
I replaced it, and it still runs the same.
It's worth noting that I had a hard time getting the new seal in, and I may have not gotten it in square. One side looked a little deeper than the other. I have a new one on order.
Someone else suggested something wrong with the power valve not opening. The arm seems to move freely up and down. It's a little black and oily inside the covers, but everything moves fine. I took the right case off again and everything looks fine but I don't really know what I'm looking for. The governor spins (it seemed a little wobbly, maybe it needs new bearings? Would that cause my problem?) when I move the kick start. The governor spring seems to move up and down. I'm really just lost.
I was hoping to race my first Enduro next weekend, but that looks unlikely
Here's a quick video of how it sounds. The passes are wide open throttle in first.
https://youtu.be/FDiYQkjf9QI
Here are some pics of power valve related stuff.
Gasgas power valve
https://imgur.com/gallery/utZYVgH
I have a gif of the wobbly governer shaft so I'll post that in a bit.