I don't intend to jet it so lean as to hole a piston or even make any excess heat. I'm also not going to up my pilot and main 3 or 4 sizes with the clip on the bottom of the needle just so I can start the thing without choke. All the data is coming from this forum so if you guys aren't holeing pistons I don't expect to be either.

Steve

 

I went from a 118 stock jet to a 124 dyno jet with no drop in mpg

 

Is there any history or evidence to indicate that will be the outcome if everything on the engine is stock? I don't know but am curious. Seems like it would be a problem for Kawasaki if so.

 

From what he was saying he wants to change modify the bike to run as lean as possible, so change the stock settings....I was saying if you want it lean just leave it stock, at least i would be ok in knowing it wouldnt be too lean. I sure as hell wouldnt want to try to make it more lean than it came from the factory... Unless you live at 13,000'

 

When I first got my bike, it got crap mileage. Maybe 45-48, or worse than my DR650.

Then, I put a Dynojet kit in it, switched to a TwinAir air filter, and put a KLX300 exhaust on it. And rejetted accordingly.

It now gets 60-65 mpg, unless I'm on the freeway running the **** out of it.

Rob

 

Thanks for the explanation. Most of my riding is @ 3500" and higher elevations with stock jetting at this point. The fuel/air mixture seems to be fine as the bike runs very well. Figured if I was going to do engine mods I'd wait until after the mfg warranty expiration. Seems like the only way to get more umph is to put more fuel/air into it not less. Not sure if I'll do that as I like the mpg I get and the overall performance is about what I expected from this bike.

 

I am not particularly **** about measuring my mpg, but I do keep rough track of it at each fill-up by mentally checking the volume of fuel I purchased against the trip odo. *I was also initially surprised that the little KLX didn't do better. In fact I can just about do better on my 1200cc Buell! (b/w 45-60mpg)
The problem is that the little 250 really needs to be wrung out whereas bigger bikes can lope around at no more than 1/4 throttle all day long.
It's not unusual; my 919 gets better mileage than my wife's ZX6r when we road trip together too.
Top Gear even did a piece several years ago showing that it's possible for an M3 to get better mileage than a Smart Car!
Regarding octane, it's lost on the KLX and won't result in better starting, more *power or better mileage so save your money (unless premium helps you sleep better at night)

 

Sometimes Premium is the only way to avoid the E factor, aka corn squeezens.

 

It's also often better quality fuel and will gum and silt up your gear less even when the actual higher octane rating isn't necessary.

 

Hey go cytosis, I figured out the non-vacuum cold start. (Sorry for the thread derail, just saw him pop up and had to mention it).
I think Deej might have brought it up?. It worked in 0ºF the other day. Get on, kickstand up, pump the forks up and down, choke it, fires by the 3rd hit on the starter, if not, rinse and repeat(only had to repeat once).

Back to fuel mileage.
The only real difference I've seen in mpg had to do with re-gearing. With 14-47 I consistently got 60 mpg. With 14-42 I get 63-65mpg. Why? rpm to speed ratio is better stock.
I also think my very cool-cold weather helps, my fuel is more dense than it would be if I were back in Tucson(10-80ºF in NH, 40-110º in Tucson). Which I actually noticed on my EX-500. I got 50mpg in the cooler NE climes for years, I rolled into Tucson and I was lucky to hit 45mpg with slower and more consistent speeds in 6th gear, nothing else changed except environment.
So making the bike cooler(to an extent) by removing the smog crap, putting a higher pressure radiator cap, and what else I don't know, should increase mpg?

I don't really care about my mpg just get a laugh calculating it in my head when I pull up to a pump, go through the long process of gloves off, tank up, gloves on and the guy in the Prius is still pumping and I got off way cheaper and with way more smiles per mile. And even more eco-friendly because my bike is mostly recyclable, but the Prius giant battery is a lot of toxic waste waiting to happen thanks to manufacturing processes. But I digress, again. I apologize. Blame my typing teacher and ADD.