I want to build a two-stroke motard over the late fall and winter. A friend of mine has an older CR500 in good shape, although I would consider purchasing a KX500 in good shape if the conversion would be easier. Anyone know what would be required to mount wheels to fit appropriate tires with modern street rubber on an older motocrosser? I figure that is my only real challenge and expense. It should be ridiculous fun on a small track like Pocono East or Summit Jefferson. Any imput would be appreciated. There's still nothing like the smell on 2-stoke oil first thing in the morning.
2-stroke motard!!!
- Thread starter MB3
- Start date
Rhino
New Member
I have not done the research on an older 2-smoker like the 500's, but for my DRZ, one of the options is to use the stock hubs and lace in new 17" excell rims. There is also a big brake kit available for the front of the DRZ. I suppose this may give you a place to start. If you have no intent of using it as a dirt bike, your cheapest option is definitely using the stock hubs.
mike574
Member
i will ask my brother he supermoto a yz 250, before i blew it up at jefferson, but you should find all you need over on the www.supermotojunkie.com tech page
also lot of sites now sell complete setup for each bike or will work w/ you
also lot of sites now sell complete setup for each bike or will work w/ you
bigkaley
Control Rider
As a current owner of a CR-500 and a previous KX-500 owner, the CR (which has no power valve) has great bottom-end and mid-range power, but no real top-end. The KX (which does have a power valve) has good bottom-end and mid-range, and still pulls on top-end.
The best way to convert either one would probably be to re-lace the stock hubs with the 17" rims and spokes.
I know that you'd also benefit from lowering the suspension and getting it re-valved/ re-sprung.
As far as pipes/ jetting, you'd want a top-end specific pipe and make sure to start on the "rich" end of the jetting so you don't burn a piston. Also, 2-strokes don't like to be held wide open in a "fixed throttle" state, so you can't just "pin it" down a straight. You'd have to teach yourself to have the throttle mostly open, but still "feather" the throttle open and closed slightly.
Another point would be that since 4-strokes have so much compression braking when you chop the throttle shut, you need the slipper clutch to help keep the transmission alive. On 2-strokes, there isn't nearly as much compression braking, so while you'd be okay without the slipper clutch, the oversize braking kit would be mandatory! You have to slow those monsters down somehow otherwise you'd run right off the track and :banghead:
The best way to convert either one would probably be to re-lace the stock hubs with the 17" rims and spokes.
I know that you'd also benefit from lowering the suspension and getting it re-valved/ re-sprung.
As far as pipes/ jetting, you'd want a top-end specific pipe and make sure to start on the "rich" end of the jetting so you don't burn a piston. Also, 2-strokes don't like to be held wide open in a "fixed throttle" state, so you can't just "pin it" down a straight. You'd have to teach yourself to have the throttle mostly open, but still "feather" the throttle open and closed slightly.
Another point would be that since 4-strokes have so much compression braking when you chop the throttle shut, you need the slipper clutch to help keep the transmission alive. On 2-strokes, there isn't nearly as much compression braking, so while you'd be okay without the slipper clutch, the oversize braking kit would be mandatory! You have to slow those monsters down somehow otherwise you'd run right off the track and :banghead:
Thanks for the responses guys. It seems the easiest route is to just use the stock hubs since those bikes aren't really competitive motocross bikes any more it would no longer be run in the dirt. I've never really had the experience with 2-strokes not liking WOT, figure shifting throgh 4th and 5th and holding on til the braking zone shouldn't be a problem, maybe pre-mix a little rich? Agree with the lack of engine braking though. Should make for a good winter project. Thanks again.
I currently am running a YZ450F and I got a complete set of wheels for mine, that way I can still swap out and go play in the dirt. They run about $1200 for the set and the brake up grade will run you about $900 with the master cylinder. You can buy everything from www.motostrano.com. As Kaley said I am running a slipper clutch, because I blew it up before from not having one, and the 4 strokers have way too much engine brake. It is a ton of fun and will be at Summit this weekend playing out there on it. 