No top and power and more smoke than usual
 

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.

Wobbly governer shaft https://imgur.com/gallery/DM4hnZC

Take the silencer off, sounds like it could be blocked. Try and run it without the silencer, of course leave the expansion chamber on.

After watching your video this is my initial thought, a partially blocked silencer will pass enough exhaust gas at lower RPM but not as the revs get higher.

Let us know how you get on, if it's not the silencer then we'll suggest other things to check.

All the best, Dave.

Don't worry about the governor shaft wobbling like that, it will do because the end isn't supported as when the cover is in place.

Dave's right about the governor.

Take a look at my post on the Sticky Powervalve thread. It's the very last post, I've just sorted mine. Your P/V is the same as my early one, and it wasn't opening properly stopping the engine reving out.

+1

Check that next.

You can check it while engine is running if you pull the expansion chamber/exhaust front off,then remove the pv cover and replace front pipe.then start and see what it does when you open the throttle,once it starts to move it should swing fully to the stop.ie.its pretty well either open/close,depending how much youre feeding it.
And its always oily in there.No issue unless pv is sticking or you like cleaning lol
Also check the vent pipe on fuel tank is clear and that you have good flow from petcock to carb.
Check main jet for blockage

Thanks for the replies. I cleaned the silencer up (I think). I'll try running without it on. I also ran it without the pv cover on and it looks like it is opening.

I'm starting to think maybe this is an electric problem? Ran through all the wiring but didn't see any wires that looked pinched. I tested the stator and everything came up in spec, but I've also heard that testing with a multimeter isn't really that good of a test.

I'll try riding without the silencer this afternoon and see what I find.

I was going to mention electrical in addition what others suggested. Had a bike do something similar. Drove me nuts trying to figure it out and it turned out to be nothing more than a bad plug wire.

Did you just replace the ignition coil?