Yes, you have it right installing the spring. Some older kits for the 300 and early 250's had you drill the slide for the same result the new spring gives you. You're OK.

Edit: On your comment about the electrical system, I'd say doubtful. Electrical issues that are intermittent are usually more common as the engine and components gets warm. Yours is the reverse.

 

I seem to have the same issue, with my 2009 250 klxs, I just bought last fall. The guy I bought it from told me it really likes to to be warmed up for a while before riding it. It hesitates badly on throttle response if it doesn't get warmed up for about 5 minutes.
In contrast, I also bought a 2006 250 klxs for my son at about the same time. His bike usually takes less than a minute to warm up before it has smooth throttle response.

The slow warm on the up on the 2009 is not a big deal, it runs fine when it finally gets warmed up, but it would be nice to just be able to start it and go. If there was something I could do to fix it I would.

 

Vacuum leak? Causing a lean condition that your motor tolerates once its warmed up? Have you removed the smog crap?

 

I agree. *In fact, I don't think I have EVER owned a carburated bike that didn't require a little warm up to prevent hesitation.

I am not suggesting that we ignore the possibility of resolving the OP's problem through tuning (particularly if it's a significant hesitation at temps over 70F), but I do also think that Fuel injection has spoiled us!

My issue with the KLX is when it comes to cold starting at freezing temperatures. *Kawasaki simply didn't develop the KLX with any priority on winter use in northern climates.

 

Winter use?...c'mon gc...it was built in Thailand.

 

I appreciate everyone's input on my issue........

But to be honest I think I'm more confused now than before I started this thread.
I realize it's very hard to troubleshoot based on my input of the issue........

I guess maybe I'm just looking for a good place to start............is the bigger pilot jet still in the running as an issue? Seems like the best suggestion here unless I missed something.

While this issue is not a show stopper it does suck......sitting there waiting for the bike to fully warm before I can go anywhere is sort of ridiculous for a newer vintage bike like a 2009.
Based on the original owner this issue has been there since he got it from the dealer.

Again, thanks for all your input...

 

Don't get discouraged, I know it's a lot to absorb. Trust me, a lot of the guys on here know their ****. It's just a matter of identifying the symptoms and helping diagnosis the problem. How about shooting some video of the start-up process where the problems are present. Hearing and seeing may help.

 

A larger pilot, IMO, is still in the mix. Why not get one and try it? It's cheap.

 

OK...great.
That I will try and see how it goes..........got a little more work on Senior (Wing) then junior (Kawasaki) is next in line.

Can you order these online or is the dealer the best choice?

Thanks!

 

If you want to ride from cold, I think your going to need another carb.
The start circuit on the stock carb is a tackon that works only at low rpm when the temps are moderate. If you put a bigger pilot jet in it, you are enriching the tuning across the throttle range from 0 to 100%. The Mikuni carbs have the similar start circuit (info from others) but they do have a accel pump, which would be a big help. Maybe you could install a manual butterfly in the intake from the airbox to the carb inlet?
An auto carb has a butterfly on the intake, even then they are not as smooth as FI. Why not get a FI engine? Sounds like you don't do much trail riding, I think you have the wrong bike.