What and where is the flywheel?

[YamahaKain]

I recently purchased a book called 'Motocross & Off-Road Performance Handbook' published be Eric Gorr. Now I'm new, and I'm looking for a second hand bike, this book I have has an evaluation for checking second hand bikes. Now what I'm going to do to learn how to check out a second hand bike is hire one, and go through it, learn how to ride, etc. But, the problem is, it mentions 'removing the flywheel cover', now I have no idea where or what the flywheel is, I need you to tell me where it is, and what it does in the engine. I know it's somewhere near the crankshaft. And if you know, how I can remove it, to look at it as my book says, and also, what does it have to do with the 'main bearings'?

Any help at all would be greatly appreciated, thanks.

 

[Chief]

Yamaha,

As you are sitting on the bike, the flywheel cover is on the left side. It should have 4 or so 8mm bolts. Lowest part of the engine, the crankcase. Round cover. Just guessing, but I believe Eric suggests looking there after you remove the cover to check for any residue or puddles which would indicate a crankseal leak (air). The flywheel contains your stator and timing adjustments. It should be clean in there. If there are any signs of puddling, add a left crankseal install to the price of a bike. It only takes 2 minutes to remove the cover, and will tell you a lot.

Also, you should have no play if you attempt to move the stator up/down right/left, if you have play, the bearings will need replacing.

Everything eventually wears out and has to be replaced, especially on a mud machine. Just try to be as informed as you can. I see no problem with buying a bike that is 2 or 3 years old. Like Eric says, the racers most often maintain their bikes the best. They have to and also have the knowhow and/or resources on upkeep. I just ate an eggroll (shrimp I think) and it really hit the spot.

The bike should have no leaks at all. Before I bought mine, I called on a bike and found out where it was at. I showed up a few minutes early and saw the bike sitting in a garage (commercial) with a puddle underneath it. It was only a year or so old. When I returned, the seller had cleverly moved the bike to the outside of the garage. It had a crankseal leak. Though he would never admit it.

I've seen in general, if it looks sounds and feels right, it is usually ok. new means nothing to me and I've bought plenty of new vehicles to know.

Strongest suggestion is to bring along a buddy who has experience to look at it and ride it before you buy it.

Goodluck and welcome to this somewhat expensive and unusually fun sport.

Sincerely,

Chief

 

[bclapham]

kain: good move on getting the book, just keep reading it several times (ive had bikes for 15 years and i still learn something new every time i read that book!), remember knowledge = power and by all means get some other basic motorcyle books, all bikes operate on the same principals. the problem with second hand bikes is that someone has owned them, but the problem with new bikes is that someone hasn't owned them! what i mean is, a used bike may have been well looked after, setup and had custom parts fitted so it might be of more use to you than a new bike and will save you money. but conversely, a used bike may have been thrashed and trashed and will cost you in the long run. you are doing the right thing asking questions now, look in your local chapter on this site, i would bet there are more than a few helpful people that would be happy to help you view a bike and guide you to local riding spots etc.

there are also a couple of good books that deal with riding techniques and these will help you get started in that department.

any questions, just ask, people here like to help!

good luck