I had the chance yesterday to try a DRZ & DR back to back. Each certainly has its own character, the DRZ being a bit more high strung and focused to off-road, while the DR is a bit more relaxed and very at ease on slab. Each is also larger & heavier than the KLX, but not by that much (~30lbs & 60lbs respectively-ish).

I have never ridden a 351, but up until yesterday, I had every intention of doing a big bore on the KLX; now I am not so sure. I'd love to hear from you 351 guys who have also been on a DRZ and/or DR, on how they compare.

I am essentially looking for some more off-road capability (keep in mind I am currently on an SF with DS tires), and better highway manners.

 

I think the DR/DRZ engine is great. I don't like the chassis and geometry of them for riding off road. I've gotten to ride a couple of friend's bikes, and there's something in their design that feels cumbersome and extremely top heavy off the pavement. Not as bad as a KLR650, but that same feeling of being a runaway freight train when pushed in rougher terrain. Being that they're not near the weight of a KLR, it's got to be in the chassis, engine placement, or both. Anyway, that's my take, and I've seen similar responses from others who knew what a lighter, more nimble bike felt like when off roading. Those coming from bikes like KLR650 and such tend to like them because at least they are an improvement. For those who do nothing more than easy 2-tracks and dirt roads, I don't think those feelings I described are that big a deal. I did ride a friend's DR400 motard model, whatever they call that one, and it was pretty neat for a motard with pavement tires...but not for dirt of course. If that motor was in a more dirtworthy chassis, I think it might be a cool setup. I don't think the DR/DRZ 400 has a chance off road compared to a big bore KLX.

 

Interesting & helpful insight! I'd have to agree based on my little test-runs. How much more competent on highways do you think the 351 makes the KLX?

 

Powerwise, I'd think they will be quite similar, but the Suzuki's I rode had 5-speed trannies, and I wasn't too high on that. Do they have 6-speed yet? On pavement I think the Suzuki will always feel more stable, but that's because the KLX is lighter and has more off road geometry. Also that may be what's going on with the Suzuki in that less-than-pleasant off road feel. That may be part of why it feels more stable on the pavement. I think the Suzuki would be better for those who won't really ride any rougher off road or 2-tracks, but the 5-speed tranny is still a problem.

 

The DRZ isn't in the same league offroad as a KLX - 300 that is. And it's also no better onroad. Very buzzy at speed with the 5-speed. It's a great motor though.

 

I've not ridden a KLX big bore, but the DRz400 would be better than either a DR650 or KLR650... or KLX650 for that matter.

I wouldn't be afraid of the engine, I ride with a guy who did his S model into a supermoto and when he would lead he was always running the twisty back roads at 75-85 mph all the time. His speedo was off because he was still running the 21" wheel speedo gear and had no idea how fast he was running. He actually slowed down when he bought an SM speedo gear for the wheel and learned how fast he was going. He got stupid mpg too. Sometimes hitting 70 mpg. You just have to not let the rpm bother you, it can handle it.

If the big bore was low enough buck and the performance near that of the DRz that would be the ticket though. Unless the compression is significantly higher the reliability should be good. I did an overbore on my 650 and am totally happy with it, but it was an OEM Vulcan piston that kept a compression ratio near the original 650 based on my guesstimate. A few points higher compression wouldn't be too big a deal though.

The build is probably the most important for having a good job though.

That's my opinion.

 

You ****! Take a cold shower, and get back on your KLX...