This article is based on the Australian model '97 XR250R/L. Of course there are many aftermarket options available and this is what I did to mine to make it a better dirt bike.

After Picking Up Your XR250R/L

After you pick your XR up from the dealer I recommend that you go over it and check it thoroughly. It might sound stupid, but trust me not all dealers pre deliver bikes as they should. This means checking the engine oil level, tension on almost all bolts and a thorough check of the whole bike.

Start by stripping the bike down (seat, tank and plastics) and checking the frame for cracks or faulty spot welds from the factory. If you do find any keep an eye on them. They may be ok for ever, but if they start to get worse then you should get them fixed.

Check the bolts on the front and rear sprockets for tightness. Make sure the rim locks are not loose, as this can cause the tube to move inside the tire ripping off the valve. The allen bolt on the right foot peg of mine was almost hanging right out when I got mine.

Starting The Beast

To start your XR250R/L, slowly push the kick starter down until you feel the hard spot (compression stroke). Next pull in the de-compression lever and push the kick starter about 30mm further down so that the piston is near top dead center. Then release the compression release lever and return the kick starter to the top of it's stroke. Finally, kick downward with a strong shove and lots of follow through, and never twist the throttle.

If the bike is cold, it will need choke, and maybe a few kicks. After a crash, pull the de-compression lever and hold the throttle wide open, press the kill switch and kick it five times. Then do the normal starting procedure. If the bike doesn't start on the first kick, repeat the process again.

Running In / Breaking In

My recommendation is to run it in for at least 100kms to 150kms (160-240 miles). During this time you should try vary the revs and not "cruise" on the road holding the one speed. Don't leave the bike standing still for long periods idling, as it is still tight and you want to avoid getting the engine extremely hot, same for when you have stopped riding you should turn it off immediately.

You should leave it restricted during the running in period or for the first 50kms (80 miles). This gives it a bit more back pressure to help the rings bed in.

Jetting The Carb

You should start or jet the XR250R/L with the following:

• Main: 160
• Pilot: 60
• Needle: 3rd clip from the top
• Pilot Screw: 2 turns out
• Float Height: 14.5mm

Use the above for a guide and work from there. I have a 162 main jet and a 60 pilot in my completely de-restricted XR250R/L. When adjusting the pilot screw, screw it right in but not tight or you will damage the screw, then count back out.

Gearing

The standard XR250R/L comes standard with 15 tooth front and 40 tooth rear sprockets which make the bike very slow and hard to ride in the bush. I changed mine to 14/44 which makes it a lot quicker and good for trail riding and Enduro type work. A 14t front sprocket will wear the chain slider quicker than the 15t, so the other option is to go to maybe 48 or 50 rear sprocket. I have heard of a few people braking the standard chain, even though it's o-ring it must be a lower quality chain ? I replaced it with a 120 link DID X-Ring. You need a new chain when gearing it down as the standard one is too short anyway, unless of course you buy a chain lengthening kit that has a short piece of chain, and 2 joining links. With a 120 link you need to remove a few links as well. Total cost is around $185 (AU) depending on quality of parts.

De-Restricting

• Intake: Remove the intake manifold taking care not to damage the o-ring between the head and carb. Once you have it off you will see how much it is restricted and where you can port it out too. Be careful when you grind it out, as it is made of bakelite-like material which is very brittle.
• Exhaust: The exhaust diffuser is held in by 2 torx (security) bolts, and you will need the correct tool to remove them. Once the diffuser is removed there is a considerable power gain but the noise level is increased also.
• Air Box: When you pull the seat off you will see the tiny hole that it tries to breath through, so you can just pull out the top nozzle. There is a aluminum plate on top that can be removed by drilling out the pop rivets on the side. I removed the whole top of the air box which makes it a bit louder, but gets more air in.

Replacing The Handlebars

Basically the standard $10 steel handle bars are crap! Replace them with a good set of alloy bars and it will feel a lot better. I put a set of alloy Renthal's on mine, and the difference is very noticeable, well worth the $90 I paid for them.

Hand-Guards

The standard plastic guards don't really work that well, and it's is a good idea to get some Bark Busters, Acerbis or cheaper copies. Buy ones that fix to the end of the bars, as they also protect the bars and grips if you drop the bike.

I have white plastic/metal bark busters on mine, and I can't see why I would spend $50 (UA) more for the real thing, as these seem to be the same. The cost of these is about $136 (UA).

Enduro / Dual Sport Indicators (turn signals)

The standard indicators won't last long in the bush the way they stick out! Some shops sell the round smaller removable type that have the rubber mount and sit close enough to the bike to not get damaged in a crash. They are around $40 (UA).

Number-Plate Placement

If you are a hard charger that likes to get a lot of air off jumps, you should consider moving the number plate to the top of the rear guard, so you don't rip the whole lot off. This will allow you to remove the large plastic number plate holder under the rear guard. To stop the number plate rubbing the guard I glue a square piece of soft rubber to the number plate. Even thought the number plate is almost flat I was pulled over by the police and they didn't worry about that, or the fact that I had the indicators removed, because it is registered and that makes them happy.

Protecting Your Bike

• Plastics: The best way to protect your plastics and tank is to cover it with clear vinyl, the type that is used by people that makes vinyl signs. It is the best way you could possible protect your bike.
• Frame: You can use the same vinyl, or buy some aluminum frame guards. They are about $100, or if you are cheap, just put on some duct tape to stop your boots rubbing the paint off the frame.

Suspension

Ride a KTM or WR and you will soon see that the XR250R/L needs suspension work immediately. Almost anyone and everyone that has had their suspension done will tell you that the five to six hundred odd bucks was well worth it. When talking to a shop, you have to be very honest about your weight and riding ability, or you will be wasting your money period.

Credits: Article written by Daniel Stebbeings and editing by 4Strokes.com.