Just got a 2010S. What's a safe cruising speed on the highway for this bike? When I mean safe, I mean safe for the engine. Can I cruise at 65 mph for an hour or so without causing long term wear and tear. Or should I stick to 55 mph?

Thanks

 

Rather than speed, you'll probably have to ask for rpm because of all the gearing options and such. You'll probably get a lot of differing opinions on this. For me I'll cruise mine at 7000 rpm for long periods without concern.

 

Are you asking about breaking the engine in, or just everyday usage?
Congrats on the bike.
Dan

 

I hit the rev limiter in 1-2 most of the time. Its a simple engine desig, less to go wrong. Valving and rev limiter are setup safe for the engine.

 

What is the rev limiter? How does it work?
Craig

 

you can run a stock klx wide open for an hour no problem

 

My bike is all stock and I ride between 60-65 mph for 45-60 minutes at a time. At 60mph my bike is turning 6000rpm and at 65mph my bike is turning 6500rpm in sixth gear. I would ride longer but the seat is very hard.

 

If you're just breaking it in, do a web search on the different methods out there.
Personally I'd do a hard break in, slowly revving it up and down the RPM range, and finally getting it up to redline.
I've done this to a few new pocketbikes and a new Scion 2.4L engine.
I never had a problem long term but since this is your bike, you should do the homework.

My SF was already broken in when I bought it used so I never care about fluctuating RPM, I just ride it however is convenient.
I'll just drone on at 80-90 mph (~7-8000rpm) on the highway until the gas runs out.
I also run it at the track and am riding the rev limiter all the time.
I have temp strips and the bike never overheats.
The fan has never come on and I'm close to the equator in Bangkok.
Seeing how a full MX 250cc makes ~twice the HP as the KLX250, this engine must be very detuned for reliability and I'm guessing the radiators are meant for a bigger engine.
I wouldn't worry about what RPM you're getting to as long as its fluctuating during the break in process.
If it's already broken in, just ride it like you stole it.

 

if you are breaking it in load it up as much as you can to set the rings, no light throttle revs, half throttle or better. i rebuilt my engine about 1200 miles ago and beat on it since i put it in. No problems.

 

I've percieved a "sweet spot" around 6200 rpm (an indicated 62 mph, probably upper 50's real world) where the engine seems to produce less mechanical noise and vibration and likes to be for long periods without complaint. Too slow for the freeway but good for long burns on county roads to get to good riding spots which are mostly about an hour from where I live.