One more happy customer to add the growing list of juvenile delinquent degenerates:

I picked up a new KLX250S a couple of weeks ago at the local Kawasaki dealer after about a weeks worth of researching and ghost surfing this forum and want to thank all the incredibly knowledgeable participants of this forum, truly one of the best forums I have ever looked at.

The elevation in the Salt Lake Valley is around 4,300ft and the little bike does OK in stock form but when I head up the nearby canyon (Butterfield) it surges with protest above 5k ft and barely runs at less then 6k RPM’s. I have logged about 300 miles on the mount and today installed the KDX snorkel and Uni filter, I’ll be getting around to punching the crankcase breather hole out to 3/8” later today.

Just took it on a 5 mile ride and can tell a slight but noticeable improvement.
The technician that put the bike together informed me that the main jet was left stock #118 and that I could bring it back once broken-in for a free high altitude re-jet (#115) but judging from what I have read on this forum even at this elevation it doesn’t sound like the thing to do.
I want to keep the bike stock looking and quite as can be but I also would like it to run well enough to take into the high country and not have it sputter out.

I have a Kouba T-handle fuel screw and N1TC adjustable needle on the way and plan to drill the slide out to 7/64” when I crack the carb open, I also plan to leave the #118 main jet in place but was wondering if you guys think it would be better to go a little larger on the jet to maybe a #120 or 122? I plan to leave the exhaust 100% stock and probably not do any other mod’s other than what I have mentioned.

Thanks all.

Dave

[IMG]local://upfiles/5126/716AEF96C0EB43F4898CDFFF0FAB6311.jpg[/IMG]

 

should think about drillin the baffles out of the exhuast at least... noise increase is minimal and will et it breathe better while maintaiing the stock look

 

Hey, Dave. Lots of possibilities on the jetting until you find out where you are starting from. What I mean by that is that you could be rich or lean. Spark plug readings used to be a good measure of proper mixture, back when we used leaded gas. The hydrocarbons resulting from burning the leaded gas left a better imprint(for the purpose of plug readings) than unleaded gas does now. That said, you can still get close. Start with the main jet. Run the bike hard, upper range of throttle or WOT, for a few minutes. "Chop" the throttle...pull in the clutch and kill the engine. Coast to a stop in a safe place and pull the plug. Sorry 'bout the fingers there, pal. I know it's hot. "Read" the plug. White and blistered, too lean. Go up on jetting. Black and sooty. Too rich. Drop a couple of sizes. Once it's nice and brown, you'll be about as close as you can get without an exhaust gas analyzer. You can adjust the N1TC needle the same way only run a mid throttle setting to take the measures. You can work out the pilot jet and air screw by test riding and checking throttle response. That's a rough intro to seat of the pants jetting. At your altitude, you will need to find your own starting point unless there is someone else of the forum who has jetted the CV for near mile high riding. The good thing about the CV carb is that it's more forgiving at altitude than the direct pulls...albeit with somewhat of a HP sacrifice Vs. a well jetted Mikuni or FCR pumper.

You might benifit from opening up the stock exhaust a little. It makes very little increase in noise when you punch the baffels. If you have a good, sharp, tapered drift or a long drill, you can drill two baffels deep into the can. It will help flow, but as I said, won't cause enough noise increase to be a bother.

Good luck!

Bill Dragoo
Norman, Oklahoma

 

I like the radiator shroud graphics...

Not too sure about the white headlight piece.

 

Ok, took your guys advice and headed out the door with my Makita drill and 1/2" bit, 30 seconds later hole punched thru 1st baffle.

Came back in for a beer then headed back out to garage with an old 3/8" drill bit and my trusty Bernz-o-matic; 15 minutes later hole melted thru crankcase breather, spun the bit to clean up the rough edges and hit the airbox with a blast of compressed air.

Test ride yielded: no noticable difference in noise or sound and possibly just a tad more power, I'll have to wait till the rain subsides so I can get it out for a decent ride.

Heading back out to garage now for 2nd oil change (292 miles), Valvoline 10w-40, K&N oil filter, Bud Light and install the spiffy little magnetic drain-plug I came across on Ebay.

 

and so the addiction begins
lol

 

welcome to the forum.

 

Dave,
You're on the right track. Once you get all the orfices opened up so it can breathe, the jetting will begin to make sense. I was amazed at how much horsepower changed with just one jet size when measured on the dyno. The trick is not to get your expectations too high. Clean running should be a primary goal at your altitide. If you have that and a nice plug color after the mods, that'll be about it until you start dropping some cash. We all have different wishes and wants for our bikes, but if you can enjoy it now, it'll only get better if and as you add ponies. These little bikes are easy to fall in love with for their versatility, looks and agility. Have fun!

Bill Dragoo
Norman, Oklahoma

 

Thanks for the help.

And I'll be honest, at this point I couldn't be happier with the bike, I'd wager a bet that when the weather clears and I head back up the canyon that it does much better now, I have no intention of squeezing any more power out of the little guy, just want to dial it in for the elevation so I can make it over the summit.

In my years I've learned that the less I screw around with things the less trouble I have.

 

Welcome, I remember when my bike looked sort of like that.