Is it really that bad to ride on the steet with the KDX?

May 9, 2007
Well, first let me say that I just bought my first dirt bike. After much research, the KDX seemed the best 2-stroke out there for woods and all around cheap fun. I have no desire to ride at the track or blast like a psycho. For me, getting in the dirt is my total goal.

Anyhow I plan to plate the green beast. Why? Because I am formally from the communist west coast where dirt bikes are difficult at best to plate. So given the history of many states, I am sure Colorado greenies will eventually ban it here too. Thus my desire to get it plated now.

Anyhow, many people have predicted dire consequences if I ride my KDX on the street. Now let me explain the definition of "riding on the street". That would be tooling around Parker, taking the backroads to work or just generally tooling around. It is NOT riding down the e-470 at full tilt for 20 miles.

So, what do you think. Will my piston turn to slag the minute my knobbies hit the concrete? Will the wrist pins snap and crank shaft eject momentarily after it its first stoplight moment?

Personally I am incredulous. To think the KDX survives Woods assualt after woods assault, yet (many claim) the very same engine will burst into 1,000 parts just mere minutes after hitting the nearest arterial.



Jul 18, 2001
I think the DOT tires will help keep decent tire life for awhile. If you are going to be doing these jaunts frequently then maybe set aside money for the appropriate maintenance as needed when the time comes.
I had 2 kdx's and a I think from what you are describing that your intended riding thru town or up and around roads for various stretches should be okay. I was riding my ktm around the neighbor hood to a 50 acre wooded lot and thought how much it would be nice just to rip it around town once and awhile. I Wonder if you could get the kdx supermotard like with some slick tires...

I am curious what some people have to say...


Sep 19, 2006
I bought my KDX in SM set-up... It didn't last long in the configuration though. I put some knobbies on and started tearing up the woods. I think having a plated bike (of any kind) is a great idea. A plate is required when riding down most forest service roads and it's just a piece of mind that you know that you can't get pulled over for having an non plated bike. My KDX has also been around town, alot. Never had any problems riding on the street other than the tires wearing out faster.


Oct 19, 2006
I've seen a lot of plated KDX's and 500's. I wouldn't consider plating my CR250, even with the bike geared 14/51, which gives it a top speed in the 70's. The bike sings at full throttle running up to 70 mph, but if you try to cruise it at speeds above 45 mph it just sounds awful. With the throttle barely cracked open doing that kind of rpm, the bike has a really uneven firing interval. At lower speeds, it fires once every couple of revs but it's even and doesn't jerk you around as much. The porting on the KDX may be more capable of cruising at high rpms. I don't know. Some bikes can take it, some can't.

G. Gearloose

Pigment of ur imagination
Jul 24, 2000
KDX wide ratio gearbox is well suited to the street. Keep your CS sprocket at 13 or higher. I ran a 15 the first few years unknown to me.


Dec 13, 2006
The engine does not mind being at an rpm for long periods of time? I suppose low rpm cruising would be fine. Does street riding conrtibute to faster engine rebuilds? I mean I hear every 100 hours or so or new pistons. Street riding would eat that up quick. Maybe it is 100 hours with high rpm riding.....

Ahh I don't know. Bottom line, is the KDX motor really suitd for street riding with out constant rebuildig? A DR or XR can go years with no rebuild on the street. KDX too?



Apr 28, 2007
Is there any relevance in this discussion to my riding my Suzuki dr200 55-70 more than at low speeds?

Something I ought to know? It's never seen the dirt, to be honest....But a dr200 is no kdx200.....

ebeck: A DR or XR can go years with no rebuild on the street. KDX too?



Aug 16, 2004
There are many different definitions of "street riding". Tooling around town, light to light, it does just fine. Try and do any extended distance on it and sucks! With 13/49 gearing my bike pulled over 80 mph on GPS. Running 50 mph is buzzy and annoying, like you are reving the life out of the bike. Gearing up more could help, but still, it's not made for extended road duty.

I put some balanced dual sport tires on mine for a while and used it to commute to work (13 miles each way, 35-55 mph). That was about the longest tolerable distance, my hands would be vibrating when I got there. I've done 60+ mile of road one day. It's amazing how much more fatigued that can make you compared to 60 miles of trail riding!

As far as durability, I don't think it hurts much. With no cushion drive hub power shifting can be fatal to transmission parts, I was careful and never had a problem.
Running too lean on the pilot can be especially bad, if you are coasting down from speed it will be getting hardly any fuel.
Extended high rpm can be bad for a 2 stroke, piston crown cooling isn't their strong point, and a burn down could occur. Again, jet properly and don't spend 15 minutes cruising 1/2 throttle at 8000 rpm and you'll be fine!
And knobbies do not last on pavement! When I only got to ride trails every few weeks I dedicated a set of dual sport tires for road riding. Changing tires for a day in the dirt was worth the $$$ saved in burned off knobbies.


Dec 13, 2006
ebeck: A DR or XR can go years with no rebuild on the street. KDX too?

That is a question not a statment. I read about guys doing dual sport rides for many thousands of miles over years of life and have yet to rebuild them. Just what I have read.

I am pretty sure the KDX motor can not do that. Hence the question based on what I have read about big dual sport bikes.

I may build a KDX for localy tooling around. 5 and 10 mile outings.


Jul 29, 2000
South America
street riding the KDX

well, I rode the SR model of the KDX for 3 years in Paraguay and never had a problem except for when I started porting it and stuff for MX. Then I seized it once when I was going about 40mph and it was right in the middle of its powerband. But before that I had ridden it on the highway many times without a problem. But maybe then the rpm's were above the meat of the powerband. I'd recommend going a little rich on the needle. Raise it at least one notch.


Dec 29, 2006
if you want to do it then do it,you only live once.i do 95% of my riding on street and dont see it as a problem.considering you"ll be in traffic you want be loading the engine to much.i have a 04 220 and love riding it on street as well as off road.i normally ride every day but just ad an op on my nose so cuddnt ride for 2 weeks so i put a wiseco piston in it and a pro curcuit pipe.i done 3200 miles on stock piston and bike was still very strong so dont sweat about engine probs because you wont get any.the miles do clock up faster and nobbys dont last to long on tarmark but the buzz factor makes up for this.hope this helps.


Feb 1, 2001
I have a 1997 220 and do mostly street on it. I run a 15/45. The KDX has such a low first gear you can get away with the tall gearing. My power valve opens about 65mph, so 55-60 mph is nice. Top speed is 91 on the GPS. Adam728 is right about using a fat pilot let it four stroke or blubber some. I love using up all my old knobbies. If you remove the rim locks, thing are much smoother on the highway. If you need them just install a second one 180 degrees from the other one. I need to find a way to document the longevity of the motor. Maybe Dirt Rider would like to do a really long term test teardown? I have 5200 miles on it now. I change the plug once a year and the tranny oil twice a year. The real kicker is it has never fouled a plug and it only gets Wal-Mart Super tech outboard oil (8$ gallon :whoa: ) at 40 to 1. :ride:


Feb 3, 2007
Hey Chris,
I picked up a 1990 KDX 200 this spring and got plates on it and ride it like you describe your plan is to. I havn't had any problems, but did notice the fast wear on the rear tire. Try to stick to dirt roads when possibile. Run up north to Wyoming if you want a riding buddy.

Dallas in Wheatland


Dec 11, 2003
I have 3500 miles on my kdx 200 mostly road miles. I have days of near 150 miles on pavement and I treat it sometimes like a short distance aventure bike. I noticed when I pulled it apart last fall that the rings were in real good shape. I thought they would be fried. I wouldn't be surprised to see 7000+ street miles on this bike before piston and rings were needed. Like everyone says be sure the jetting is a little rich on the bottom end (where your throttle will be most the time)and be sure there are no lean spots in the throttle and run a good syn oil at probably 32:1 to protect the crank and let her rip. IMHO


Sep 8, 2007
During the week I have a set of super moto tyres on my 94 kdx 250 to tool around the city and at weekends I put the knobbly's on and take it off road . This includes sand dunes, slag heaps, mud and forest tracks. I then jetwash it, do a little basic maintainence (thats about as far as my knowledge lets me) change back to supermoto tyres and back to town ridin during the week.
The only 'proper maintenance' is done on a yearly basis by the local garage.


Nov 18, 2007
I run a Kenda Trackmaster K760 on the rear, and a Pirelli MT16 on the front of my DRZ400S. Both are very aggressive DOT knobbies, and I just replaced the rear at 2100 miles. Can't beat that for a $50 tire. I run 20-22 psi on the road, and air down to 14 psi for the trails.

I'm thinking about plating my 05 KDX200, and will probably run the same combo.


Dec 15, 2007
I got my 95ish 220SR about a year ago, with 6000km`s on it. Looked almost brand new, probably never seen dirt until I bought it. Came with 14/42 sprokets (OEM) which I replaced with a 14/45 set-up. Run`s great, never fouled a plug, and a total blast to ride on the street.
Was the street-legal version not sold in N.America?


Jan 7, 2008
Hey guys, first post here.

My bike used to be road registered so im thinkin of getting that sorted again and takin the kdx to work one morning for kicks.

Its about 5 mile of 30mph cruising followed by 3miles over a big nasty hill at 50mph then a bit under 2miles through town. Is this the sort of street riding the motor can handle?

Ive just always wanted to light up a tire in the store-room and my car wont fit in there :debil:

If not ill just leave it de-reg'd as thats the only trip id be doing on it. Oh other than maybe gettin my bike licence.


Feb 9, 2007
I think it will be fine. That is a pretty short trip.

Listen to the cautionary posts above, and avoid chopping the throttle to decel the way you would in a car or on a road bike. Keep it a little rich on the pilot and don't crank the air screw out very far.

The problem with road riding and a 2T is that the road offers lots of opportunities to get the motor to high rpm then chop the throttle, such as accelerating from corner to corner. The motor stays at high rpm for a while due to your momentum, but very little oil (remember the only source of oil is the fuel oil mix) is getting to the motor. Oil injected 2Ts are better about this, as the amount of oil injected also depends on rpm, not just throttle position. This also happens on long fast downhills.


Jul 18, 2007
I ride mine to the trails and do some pavement and dirt road riding to get there. Does fine, the hard part though is resisting the urge to go WOT and start running through the gears. I don't do enough to notice much additional wear on the knobbies and I make it a point to use the brakes and not the engine to slow down. I usually clutch and blip the throttle while slowing and while sitting at the stop sign. Anyways, its fun, just have to keep the impulse to find out how fast it will go in a 1/2 mile stretch under control. Oh, and in Cali where I am at they are ok with it as long as riders do keep it reasonable. Saw a cop helping a rider whose bike was having problems. Pretty small town atmosphere here which is nice.
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