Best thing to do would be go to the dealerships and sit on both the 250 AND the 450…maybe some others aswell

whatever one feels most comfortable to you is best. dont get one you arent sure you cant handle because beginners luck means a lot of crashes on a dirtbike.

obviously 450 is going to have 200 more cc's then a 250 so its going to have quite a bit more power. its is also going to be alot heavier. it might sit a little to high for someone your height though?? im not sure…the last time i got on a 450 i was like 6 (riding on the back of my uncles…im now 15 but a mere 5'3…so as you can imagine something that big is of no use to me! lol). but anyways…my uncle is a big guy…like 6'2 sooo…ya.

the 250 will sit lower and be easier to handle…it will probably be a good first bike. it will have plenty of power. and dont worry about your weight being a factor…both bikes will zip around like crazy with a 200lbs dude on the back no problem.

I think this is one of the best ways to sell your bike…..http://ww2.cycletrader.com/browse/category/mx

Yam's usually outperform but need more repair. They're a pleasure to work on. The only Honda I prefer is the 99 – 2005 cr250r. (2 stroke). If I was buying new I'd get a Yam for sure. The honda 4 stroke mx bikes have been splitting their valve seats and cost major $$$ to repair.

The maintenance schedule will not be anywhere near as intense for a 2-stroke when compared to a 4. The top end will probably be the biggest hit on your wallet. Expect to do this every year or two (a lot more if you get into racing with it). People on here will say stuff to the effect like, you have to waste time measuring the oil to mix in with the gas. If you think about it, as much as you're changing the oil on your racing 4 stroke like maintenance requires, you'll be dumping every 2-3 rides almost the equivalent of what I'm mixing in. Use a good synthetic oil for whatever bike you choose (my personal favorite is klotz, but there's a lot of good stuff out there). Of the 3 bikes you listed the YZ is the best bet. Honda's CR250 is no longer in production and had weird jetting issues. The KTM SX is super light but does not have the power spread of the Yamaha or it's spot-on suspension. Is the new bike going to be used for trail or MX track? The KTM 250 XC would be a better bet if you plan on riding woods.

There is no place better to ride motorcycles
then in california street or dirt.

That really isn't the best way to find a dirt bike for sale that you are looking for. The likelyhood that somone would respond with one within your price range and within driving distance and the type you are looking is slim to none.

Your best bet would just be to go on ebay or craigslist. If there aren't any up, you could try looking under ebays completed listings at bikes that didn't sell and ask to see if they still have it and it's still for sale.

And one last thing, 2 stroke vs 4 stroke really does make a difference. the 2 stroke 250 would be more along the lines of a 4 stroke 450 powerwise. I'd reccomend a yz250f.

I think your friends have it about right. I like 2 strokes but in 2009 every one is going to stop making them and go to 4 strokes. if you wanted a 2 stroke I would go with a 125cc two stroke. if you want a 4 stroke, i would say no smaller then 250cc.

I dont live there, but your best bet is to go to your local motorcycle dealers and ask them if they know of any, If they don't know of any trails, they should know of some parks.

Also just look for powerline roads, there is usually trails that run along them.

You looking to ride on trails or on a track.

There are 2 kinds of engines.
2 stoke (not sure if they are sold new anymore)
4 stroke.

A 2 stoke 125 has the same power as a 4 stroke 250 – basically.
All 2 strokes are on the way out.

So assuming you will only look at a 4 stroke – maybe a 250 or less would be ok for you. You have to find out the stand over seat height if looking at used bikes…and make sure you can reach the ground.
A 125 4 stroke would be best to learn on but you will outgrow it in a couple years….not from size but from power – you will want more proably in a few yrs.
Buy a used bike for your first one – then after you learn and get better then get a nicer bike.
Dont forget the helmet and be safe.

Ebay.com
craigslist.com

http://www.minidirtbikers.com