Dirt Rider Magazine

Nope

I would take the tank off clean it out put gas back in it with seafoam or clean the carb, change all the fluids on the bike and both filters, I would do that asap

Alright. The tank is almost out of fuel and I put some ethanol equalizer and some seafoam in it, so im just gonna let it run out and then put new premium gas in it. And there is a loud whirring noise coming from the cylinder i dont know if thats normal or what, it sounds like the timing chain. I'm not used to the sound of racebikes so i wuddnt know.

Nope. never riden for more than 60 hours though.

He already checked the valve clearance recently. It starts on one kick and it runs steadily. Just a loud whirring sound i haven't heard on a trailbike.

Let me look in book, there's a troubleshoot section

So it's lacking power,bogging

did you turn idle up

4 stroke mxers make that noise. It is kinda skeery

It says could be,faulty ecm,faulty ckp sensor, dirty not clean frequently enough air filter, meaning sucked in dirt, camshaft, faulty plug, faulty ignition coil, remove and inspect the cam Lube height,valve timing, ignition timing,faulty regulator/rectifier,faulty condenser, exhaust valve,,,,,,,,,,,,that's the troubleshooting for what you described in hand book

Turn it up a little see what that does

I had 20 bike n im a beginner man,I dont like working on new bike, it has mad sensors, is fuel injected I dont like messing with it, does your bike take two different oils? Tranny right side motor left side

Aight. The previous owner says i has been set for 180lbs

You probably just need to release the air there's a air pressure screw on the side, Titan the dampers all the way up,then come down one click intill your happy with it

There is some sag when i let it off the bike stand but its stiff when i ride.

I use 80/85 Honda pro gear oil in tranny and 10/40 in motor.

As far as suspension set-up goes...you'll need to set the sag. This requires two people  First, you need to put the bike on a stand with both wheels off the ground. Measure the distance from the rear axle to a spot on the rear fender(mark this spot with masking tape and marker).  Then, remove the stand allowing the bike to rest under it's own weight. Use a tie strap to hold the bike upright.  With all of your riding gear on, you now need to stand on the foot pegs in riding position with hands on the handlebar, Have a friend re-measure distance from rr axle to same spot on rr fender. Should be 100mm/4in shorter. If it isn't, you then need to adjust the spanner nut on the rr shock. then re-measure. If you still can't achieve 4 inch sag, you'll  need to change the spring rate. Hopes this helps.          

Thanks for the advice guys. I set the sag on my bike which was already normal to start with, and finally got the brakes solid and the fluid completely replaced. I used a vacuum pump bleeder to do it. And yea, i wasn't used to the noise of the bike, being that this is my first race bike. How often do i have to have the engine looked at? I know i have to check valve clearance and stuff like that, but when do I have to replace components of the engine?

Alright.

If you feel like you have pressure in the brake line check your front brake pads as they wear you will get more pull at the lever  If you have bleed the brakes and the pads are fine the the master cylinder may need a rebuild.
If your forks feel stiff on landing try adjusting the compression both softer and harder.  I would recommend setting the compression in all the way  (soft) ride a lap take some metal notes adjust the compression 2 clicks harder and go for another lap. keep doing this until you find a setting that lets you ride the track comfortably wright down how many clicks from soft you are then continue one click at a time until the suspension feels hard wright down that number.  This is your adjustment range once you have a soft and hard setting you can adjust within that to meet the track conditions.
As you get faster you may want to rework this range you typically find that the faster you ride the stiffer you will need the forks.
You should use full travel on the forks on bigger landing but it should feel smooth and controlled.  If if just feels hard on big landings it could be set to soft causing you to bottom hard

Use this spring rate calculator http://racetech.com/ProductSearch/1/Honda/CRF250R/2007 it is a good resource.

You need to bleed the air off the front brake line. We have own many CRF 250 Hondas from 2005 to 2008 and the best way (and cheapest) to reduce the infamous "Honda bog" is to lean or drop the needle one notch. The forks also build up a lot of air becoming stiff, bleed out the air by unscrewing the bleed screw on top, or get some aftermarket bleeders. Adjust your rear sag to 4 inches, and back out the high speed compression (red nut on the side of the shock) one turn. We left the other adjustments stock and worked fine. Also check the engine oil (left side) every ride, all CRF 250 seem to use a little bit. On the tranny side we always used ATF Type F oil (750 cc), and it worked great, never had clutch issues and shifting was smooth.

To start the bike cold, turn the choke on, give it gas by opening the throttle about 5 times then it should start with 1 or 2 kicks.