Nothing but smart replies on this forum. I have been riding since I was 4, I'm 32 now, but have not noticed one before, the oil plugs I'm used to are on the crank case. didn't realize it went through the frame on some four strokes. Guess I havn't been riding long enough to learn everything you know.
jsmith, the bike you saw had a dry sump motor and carries a large amount of its oil in the frame. The Hondas use it as a means to help cool the motor prior to the advent of liquid cooled 4 strokes, plus it has other benefits such as less crank windage and more consistent pressure when the bike is jostled around during riding. Keep in mind you are seeing the evolution of the 1983 XR500 when you look at a new XR.
The new KTM RFS don't carry oil in the frame like the Honda and the Yamaha YZ/WRF bikes.
When you do get your 250, take a good read of the manual on how to check the oil. Dry sump systems can easily be misread and overfilled. The drill on the WR/YZ was run the bike for 3 minutes, hold it up vertical off the stand, turn it off, let it set 30 seconds, then take a dipsitck reading. This works on the Honda too I am told, and the reading is taken without screwing the dipstick in, just setting it in until the threads touch.
Another common mistake made on the dry sump motors is not pulling the oil drain plug in the frame as well as the engine. I have a friend with a '95 KTM RXC with 3500 miles on it. When I did an oil change on it for him, he wanted to know what I was doing with the wrench on the frame - he had never drained all the oil out of the bike! Interestingly, the LC4 KTM has the dipstick on the engine. You have to partially fill it, run it, then top it off and check it.
No you are not an idiot for asking this question and it is a perfect example of the point I was trying to make on the other thread here about the XR250. I advocate spending the time beforehand with the bike so you don't fubar the bike or yourself on the first ride or two.
Had no idea of its use, but I think I understand now, thanks for the insight texkdx, I am leaning toward a WR250 now, I have found one for 5400.00 OTD. I have read these are better than the XR250 in some ways, suspension, power, etc. Although I am sure the XR is a fantastic bike. I really just don't know which one to get. I want something I can ride fast occasionally with my friends & ride very slow with my son's XR50. We have some great trail riding around here.
jsmith811 i have a 2001 xr250r and love it. i ride once or twice a week for the past 9months. the only thing is i like to jump and two weeks ago i started to bottom out the shocks big time!! i am thinking about a new bike like the wr250 or a yz250f so i can trial ride and jump with out trashing my bike, the xr is good but if you want to jump the shocks are not set up to take a 8ft drop.
good luck mike
Ya, I sat on a WR250, the seat height is 39.3 I think, the CR250 is only 36", I guess I'll be getting a WR250 though, Sounds like a Great all around bike with a few modifications, like the gray wire, Throttle stop, vortip, etc.
The only thing I'm worried about is the Maintenance on a 4 stroke, like valves & etc.
Basically, the WR will require the same maintenance schedule as your two stroke. Meaning that if you race every weekend, you'll be tearing into the top end pretty frequently to replace the piston/rings and maybe timing chain.
For general trail riding use, we all know of people who've been riding a CR or YZ for years without a top end rebuild and the thing's as good as new. It will be the same for a four stroke (more so the XR that the WR).
Use a good quality oil and change it frequently -- like after every weekend of riding -- this is the best insurance you can buy.
Other than that, regular checks are about the same as the two stroke. The only thing that's difficult is adjusting the valves, just because you've got to have a bunch of shims. Check with dealers around town to see what they charge to do this. With regular trail riding, I'd have them checked first after about 20 hours (normally they don't need shimming, but it's good to check), and then every year after that - unless you're really hard on bikes!