It might be something with your technique. Especially if you are used to power wheelies. I only recommend power wheelies for people to get used to the feeling of weightlessness, I don't recommend it get used to clutching up wheelies, because it is much more violent. When powering up a wheelie, it comes up smooth, and at a reasonable slow and stable pace, and if you ever need to go down, you just back off the throttle a little and it rolls down smooth. Clutch wheelies, are a whole different monster. They fly up fast, threaten to throw you over, if you roll off the throttle you'll slam down hard on the ground, if you give it too much you'll go over, if you give it too little, you won't do anything. There is an art to clutch wheelie'ing. It is much more than just mashing on the throttle. I could let a 6 year old take my Buell out and throttle up a wheelie.
When you want to clutch up a wheelie, a good starting point for most bikes is around 40mph. Obviously depending on the size of the engine, weight of the bike, engine position, rider position, and tons of other factors, a little more or less speed may be necessary, but 40 is a good starting point. It is fast enough on most bikes to give you a decent rpm at which to make enough torque to get the wheel up in 2nd, without being so fast that you are scared to be on one wheel. Much lower than 40 on most bikes, you will have more luck in 1st, and I've read countless threads that say to practice clutch wheelies in 1st. The best advice I can give you, DONT! Clutch wheelies in first are a lot harder to master, and a lot less forgiving than in 2nd. The torque multiplication from 1st to 2nd on my Buell is nearly double. It is not quite as drastic on my GSXR750, but the same principle applies. The lower your gear, the more torque, the faster the wheel comes up, the less control you have, the more small mistakes affect what the bike does, the more likely you are to get hurt, or hurt your bike.
The Technique: Get up to about 40mph or so (You can always adjust faster or slower later if needed), hold the throttle steady at 40mph (Do not speed up before the wheelie! This will take away from the pace at which your rear wheel changes speed, making it more difficult to get the rear wheel going faster than the front!), pull the clutch in, and give the bike a very small amount of throttle AT THE SAME TIME as you aggressively "pop" the clutch. If you hold your hands out in front of you and pretend to do this, your left fingers should flick out at the same time your right wrist moves forwards. Pretend your left fingers, and right wrist are tied together. They need to move AT THE SAME TIME! Slowly increase the amount of throttle you give it until you reach your goal. DONT RUSH IT!!! I've seen tons of people ruin bikes and get hurt because "They are good riders, and they don't need to take their time". Take it from someone who has been doing this a long time, less is more! If it takes you several weeks to get this, GOOD! As long as you get it, and no one got hurt! It sounds like something your dad would say, but this is something that can seriously mess you up if you rush it. If you have given the bike 1/4 throttle and got the wheel up, but it still isn't comfortable, KEEP DOING IT!!! It's ok to repeat the same steps over and over until you are comfortable. Don't give the bike any more throttle just to "Look cool to your friends" or whatever. Just take it slow.
Steps in order:
2. Steady throttle.
3. Pull clutch in, and quickly release with a simultaneous shot of throttle (START SLOW!!!)
Once you have gotten used to this process, and are comfortable getting the wheel up some (Will likely take several days if you practice a few hours a day, less if you have an entire day or two to spend practicing), you may try moving your left foot to the back peg, and finding a stable position. This will move most of you bodily weight to the rear, and allow the front wheel to come up much easier. BUT!!! Make sure you start THE ENTIRE process over!!! 40 mph, tiny bit of throttle!!! Don't get used to giving it quarter throttle sitting down and expect standing up to give the same results!!! It will take half as much throttle or less to get the bike up once you put a foot back!!!! Make sure to always keep your right foot forward to cover the rear brake if you don't have a hand brake. 4 Cylinder engines run very smooth and don't create much engine braking force, so if you screw up and both feet are on the back pegs, you might not be able to bring the bike forward again, and may flip over backwards.
Good luck man!!! If you are still having trouble maybe shoot another video and post it up! Hope this helps!!!
SPARTANS NEVER DIE