Set a study schedule everyday. It's good to plan your day in advance. Set a specific time for studying, and a time for playing or relaxing. This way, you won't worry about 'missing' your fun. You may be studying hard now, but you know that later on you'll be enjoying yourself. So this keeps you focused on studying in the present.

Get started with the 5 minute challenge
The hardest part of doing anything is to get started. The first step is always the toughest. But once you got that out of the way, it's all downhill. This is because it's much easier to sustain something once you've got momentum. To help yourself get started, this is what you can do; whenever you don't feel like studying, just plan to study for 5 minutes. That's it, just 5 minutes. Tell yourself that you'll be studying seriously for 5 minutes then you'll stop. This makes things seem less painful so it's easier to get started. Usually, what happens is after the 5 minutes are up, you would have been well into the swing of things that you'll want to continue studying longer. The key here is to make sure that for those 5 minutes you are really studying 100%.

Stop/start at the fun part
When having to stop for breaks, meals or other activities, plan to stop when you're at a fun part of the subject. The parts that you find more interesting and enjoyable. This is so that when you continue to study later, it'll be much easier to get started because you'll be starting at the fun parts.

Remove distractions from your surroundings
When you got the TV, phone, computer, bed, magazines etc nearby, you'll be easily tempted to throw your books aside. Try to remove as many distractions away as possible. When the remote is right next to you, you're more likely to pick it up. It is the same with your cell phone, laptop etc. But if you have to walk all the way across the house to watch TV, chances are you'll be less likely to do it.

Set Goals
When there's a target to aim at, we'll be more determined rise up to the challenge and push ourselves to achieve it. That is why setting goals will increase your motivation levels. The sense of satisfaction you get from the achievement of the goal is also a confidence booster.

I am a big proponent of positive reinforcement, which you can use to trick your paradigm into informing the tasks you feel adverse to. For example, in high school I was really only interested in music and art classes, until I realized it was important to me to have choices when applying for college. Despite the fact that classes and grades were personally unimportant, I came to see them as an annoying and acceptable means to a worthwhile end. You might overcome your value of doing chores if you find something about it that's personally significant to you, eg: you appreciate a clean kitchen, or you appreciate the feeling of a completed task that you don't have to think or stress about as you ride horses for the rest of the day.

Perhaps you could ask yourself: Why could you want to do these things? because they improve an aspect about something you are naturally motivated to do? If you are like me and enthused about a particular group of things, then finding a way to relate the "meh" things to the "yay!" things could help.

Also, you could perhaps consider setting up a reward system for yourself: eg: If you do all your homework when you get home, then you get to watch a movie that night. No homework, no movie.

good luck to you :)

Two things.

1) In response to what saroid said, a great way to motivate yourself to get stuff done is to incorporate it into what you're doing. So, let's say you like music, you can listen to it while you clean. Do a little dance, shake it up. Some music may be nice to listen to in the background.

2) You have to make a schedule for yourself. Set aside time for each task each day. Knowing that you have to do homework at a certain time frees you up from thinking about it the rest of the day. Try to also schedule some good stuff in between the bleh stuff. Do 15 minutes of homework. Take a 5 minute break to get some pent out energy out... do jumping jacks, dance, check your email. But, then go back to doing your work after the 5 minutes is up.