Hello everyone. Very excited to have just picked up a 2012 250s with 5700 miles. I am an old MXer from back in the day (1970s) and also raced about 5 years ago down in the Portland Or area. I had a nice 2003 YZ 250 2 stroke. Was sad to sell that one thats for sure.

So now I am back on a bike again! Just got it yesterday. Its one of these bikes that the guy just rode it, not really interested in maintenance. I pulled the plug out last night, never been pulled. Replaced that.

I love to work on my bikes, maybe more then riding them I think.

The only mod is a slip on Power Core 4. Header is stock and he said he had never gone into the carb,

Fork seals and shift shaft seals need to get changed

So here is my list, mostly engine stuff right now.

Oil Change and filter, clean air filter. I have pulled out the snorkle, might mod the lid. I need to check valve clearance. I want to put in one of those manual tensioners? MCM cuz its super EZ, and reversible. Want to pull off the KACR but need to know if I should just remove the spring? I know the MCM will index the KACR off buy 10 degs so that will bug me if not removed or re-indexed.

Now for the carb. Where I am in Alaska, I normally go more rich on everything by 5% Thats on a correctly jetted engine. The air density here requires more fuel to keep the engine happy. Have not pulled the carb yet. Does this carb have a needle with 5 grooves? I was just thinking of putting a 40 pilot and maybe a 132 main and raising the needle but it cant be that EZ. The parts book shows a 118 main I believe. I might do the DJ kit?

Thanks!

PS hellava forum here, the stickys have great info. I have been on here for hours reading stuff. This bike might be one thats going to be good for me now. I am getting near 60 years old!!

 

Here is what I've learned in the last two years on my KLX:


If carb is stock.. it's probably lean for a slip-on and is definitely lean for making changes to the airbox.

DJ kit 2152 is easiest way to get the carb in shape.. pull the snorkel and set it up for Stage 2. The DJ needle has the 5 grooves and the right taper for the 250. Note: no pilots in the DJ kit, so get a 38 and 40 from a local dealer or online.

MCM is pretty easy and wakes things up. Some folks just pull the spring on the KACR, some use a wire to hold it open, and some press it off. I think all options work just fine.

Once you get bored with DJ Stage 2 , pull the lid and use KLXster's lidless recipe... it rocks.

If you are going to do the fork seals, consider putting Gold Valves in the forks and getting springs to match your weight.. well worth the money.

Also: CVK carb is lazy but forgiving. You can make it 100% better with a quick-turn throttle tube.

 

Posting to give you easy access to the lidless recipes (on signature line below)..

Only logical solution to the KACR is to simply pull off its' spring - making the MCM easily reversible..

 

Thanks guys!!

Sounds like the starter can handle the deactivated KACR. And thanks for confirming pulling the spring is ok to do. I missed the fact the DJ kit does not come with pilots. I get my jets from jetsrus.com for most of my stuff.

Is the pilot a N424-25B ?


https://www.jetsrus.com/a_jets_by_ca..._selection.htm


This thing is so lean right now its pathetic. Getting the pop pop pop on decel. I can just feel she is starving. Plug was white too. Hope the first 5700 miles starving for fuel didnt hurt the top end too much.


Oh, thinking I might jump right in to that lidless mod too!!

1/4 turn throttle and forks, frame and the rest after I get the engine dialed in.

 

Yep that would be the one https://www.jetsrus.com/a_jet_kit_di...50_KLX250S.htm

 

You will be using the DJ140/1N , K152/1N Lidless solution. The DJ2206 or DJ2152 kit will have to be bought - but only the kits' needle , needle clip, and needle washers (2) are used for lidless running - everything else in the kit(s) is trash (including the instructions) when setting up for lidless running.

For the denser air in Alaska, you could go up one jet size from recommended - so you should consider getting a DJ142 and a DJ146 - or Keihin 155 and 160.
You bike must have the stock slide spring and a stock sized slide lift port (not drilled oversize)..

Get the #40 Pilot.jet.

Once you feel MCM + Lidless power, you may want more. So add a FMF Megabomb or Powerbomb header, drop in the Dj146 or K160 main jet, and it'll stretch your arms all the way to redline (10,500 rpms)..

 

Wow, great information! Thank you.

I want to run this by you: I was thinking of avoiding buying the DJ kit but needing the DJ needle might force me to buy the Kit. here is what I was thinking.

Lidless airbox with Stock filter.
#40 pilot jet is on its way.
Shim the stock needle?
Not drill the slide and retain stock spring?
I have a ton of Keihin main jets, but max out at #150 so use that.
Fuel screw to 2.5 turns out
MCM mod and set my In and Ex clearances to spec
Remove the KACR spring
I have the stock header and its got a Power Core 4 on it.

Thoughts?

Thanks again for any input

Chuck

 

You can buy the N1tc adjustable needle from Kawasaki and use the Kehin mains.
See my sig for my lidless setup

 

The K150 won't fuel your bike correctly regardless of the needle.
The stock needle will not fuel your bike correctly, shimmed or not.
Stock spring and stock slide lift port are required for lidless running/power.
At or near sea level, the proper fuel screw setting for the #40 pilot jet is at or very close to 2 turns out. Use the midway point between lean and rich idle drops (at stock idle speed of 1250-1300 rpm) to find the exact setting for your area.

 

Ok, sounds like I am going to order up some larger jets. #155 ? #160 ? Going to stay with Keihin jets for now

I googled a bit and came up with Part Number 16009-1912 for the N1TC needle?

Will go with 2.0 on the idle mix.

So I should keep the stock spring and not drill the slide right?


Shift mechanism stop post/pin bent. Will start a new thread to explain. Like to give back. But my guess is most people know about that one from the member here named Dan?

Thanks again!

Chuck