Read the thread and study the pictures, multiple times. If you have torn into an engine in the past it should not be a problem. The hardest part for me was the valve cover gasket, serious PITA. Second was retiming the ACR. Its a good time to install a krieger tensioner as well.

 

The ACR is my MAIN worry.

Everything else is kinda easy looking to me.

 

Kansas-klx has a good post on page 20 (post 198) on how to remove and replace the ACR without a press. It worked for me.

 

I have starting issues with my KLX250s, it's a cali model,I got it used with 522 miles on it was dropped by the original owner. It cranks and cranks with the enrichmener on I have to play with the throttle to get it running, I am going to remove the emissions trash off it tonight. I cleaned the carb, and air filter, put in a race spark plug,any suggestions?
also
I've been toying around with putting a KLX300 cylinder on my 09' 250s then boring it out to a 351, changing the drive sprocket out with a 13 tooth from the stock 14, while leaving the the cams, springs and intake ducts stock. I have tossed the air box lid and snorkel already.
Has any body done this yet?
If so what is are the numbers?

 

Try putting the lid and snorkel back on until you rejet.

 

2veedubs: ok will reinstal the lid and snorkel. Should i go leaner than a 118 main jet?

 

Your best bet is to start a new thread on your problem, due to your elevation your setup will differ from most on jetting.

 

That "press-less" method is what I used since I didn't know anyone with a press, nor did I want to buy one. Otherwise the mod is relatively simple as long as you are careful. I agree with 2veedubs that the valve cover gasket is a PITA. If not done right it weeps down the cylinder. As for the results, after 200 or so miles, I am happy that there is a little more punch but I still want more torque, without loosing highway speed. I'm about 10 miles of 55-65 mph before I can get to the fun stuff. So I need my current 13t front, stock rear gearing. Getting about time to call Bill...

 

Did you play with jetting, i bumped up one on the main. It pulls well, i put the 14t back on for street use, pulls it just fine. I also have full exhaust/dynojet kit/k&n/kdx&stock snorkel/no screen. What other mods do you have? Glad to see people are not afraid to do a little wrenching. This mod gives a stock bore some needed personality.

 

Yeah, knocked the clip down once (raising the needle) which helped. Later I moved it down once more and that really helped. Other mods were removing all the California smog junk (no performance benefit) but it looks better. Haven't cut the screen out yet.
I should add that I came to the KLX from a WR250F that would lift the wheel anytime, with ease. The KLX, now, will pull well but not nearly as hard. That has been the price I paid for a plated bike.