Advice on first MX bike...

[texas_moto]

Hi Everyone!

I have been riding street bikes for the past five years and after some pressure from my 13 yr old nephew, decided to sell the street scoot and "get dirty". We both took the MSF Dirt Rider Course at the local Honda dealer, so the next step is a bike. (Gear is not a problem. I am a huge safety nut and riding on the street clearly shows how important the proper gear is!) :nod:

The only motocross/dirt bike I have access to is my brother's 2003 Honda CR250R. It has a ported and polished cylinder, Pro-Circuit pipe and silencer, 52-tooth rear sprocket, and adjustable Factory Connection suspension (175 - 200 lb rider). Naturally, I have a few questions:

1) Is this too much bike for me, both for age/size (35 years old, 6', 190 lbs.) and skill level (MX-dirt beginner/newbie)? If it is too much bike, what would you recommend?
2) I have excellent throttle control on my street scoot. But my brother keeps telling me the two-stroke has to be run wide open or the engine will wear very quickly from carbon buildup. Is this true? Should I stick to a four-stroke?
3) Will dropping the rear to a 49- or 50-tooth sprocket "tame" the bike a little?

Thanks for all of the advice! I am very much looking forward to having some fun with this! :)

 

[robwbright]

At you height and weight I would think a 250 2 stroke would be a great bike to start on - unless you're intimidated by it. Just take your time and get used to the "hit" of the powerband. Most people would not recommend a 125 for your height and weight. Not really enough power and they are more difficult to learn to ride because of the "peaky" power spread.

KTM was making a 200SX for motocross, but I still think the 250 would be a better choice.

A 250 or 450 4 stroke would also work well and have a smoother power delivery. The 450s have TONS of HP and torque - so much that when I've ridden them I have trouble exiting corners without spinning the rear wheel out - but I weigh 145 lbs. A 250 four stroke has about the same HP as a 125, but a LOT more torque than a 125 and thus are easier to ride.

Carbon buildup from non-wide open throttles causing excessive wear on 2 strokes? Not that I know of.

Some people do have trouble with 2 strokes fouling plugs when they are "bogged" around, but if it's jetted right, I can lug my 125 around in the woods for extended periods with no issues.

Dropping a couple teeth on the rear won't make a lot of difference - a bit less low end and a bit faster top speed.

 

[FruDaddy]

Based on your age, size, and street experience, I would think that a 250 smoker would be fine, as you already understand how dangerous stupidity can be. I do not agree with you assumption that "riding on the street clearly shows how important the proper gear is!", since I never really took safety gear seriously until I took to dirt and put myself "in harms way" on a bike. All who have seen the cruiser riders in the shell helmets know what I mean, of course, I left my little helmet in Georgia when I moved and only brought the full face for street riding. I digress, and am not sure that your brother really knows what he is talking about. While the smokers do prefer to be opened up, you can run a hotter plug (brain drain occurring, but I know it is numerically lower) and modify the jetting for good riding at lower speeds while learning. Two strokes are also known for their sudden, violent, power hit, but with a larger bore, even that isn't really an issue. As for the gearing, yes, it will probably seem more mellow, even weaker, but you shoud probably try riding it a few times before changing the gearing, most likely you will be changing it back in the very near future anyway.
For reference, I am over 30, and when I started riding I was around 200 lbs, my first and only bike so far is a KX250. I also have a few thousand miles of experience riding cruisers on the street.