Hi Guys and gals, first of all this is my second KLX I had a 2006 that was fully tuned with aftermarket exhaust and it ran really good. Opportunity presented itself were I was able to sell my 06 at a small profit and upgraded to 2010 with only 3k miles. Bike is in like new condition. It is also stock.

Today I took the carb out and it looks like main jet is 118, pilot 40. There is a small star washer under the needle. Mixture screw was out 2 1/4 turns. My elevation is 800-1000ft. I deff noticed that the bike is not running optimal. When its cold it starts fine. When hot it will not start without at least a 1/4 turn of throttle while cranking. It will start every time and I put about 1000 miles on it so far without any major issue. I had only one instance after running it hard on the trail that it did not want to start after lunch break , it was in the 80's that day. That is the only instance that the bike gave me hard time.

Today after I took the carb apart and noted the jet size I opened the air mixture screw another 1/4 turn to bring it up top 2 1/2 turns out total. Bike is is deff snappier and hot start is slightly better to where I have to hold the throttle just barely cracked to start and it barely turns over before it fires up now.

Just wondering if anyone has any jetting advice for a fully stock machine. I really want to keep the stock exhaust is possible. Is there an optimal setting that someone has worked out for a stock exhaust. Im open to removing the lid of the airbox if that helps. Right not if I remove the lid the bike bogs when I open the throttle.

I look forward to your responses, Moe

 

Not a carb expert like klxster, but the pilot seems a bit too large. I am thinking the stock size is 35. Considering the way it starts well cold and less well when hot, I'd say buy several different sizes of pilot and main jets and experiment: smaller pilots and larger mains. Make one change at a time and see how it goes judging based on things like plug color, fuel economy, starting, lean surge, etc.

 

It appears the consensus on the FB page is to remove the snorkel or replace it with KDX one. Main jet 128 and pilot back to 35 and that even with the stock exhaust it should work pretty well.

 

The following is difficult to do - but only has to be done ONCE !

With a hot engine, set idle speed to 1200 - 1300 rpm (1250 rpm is perfect). While idling, turn fuel screw inward until the idle begins to drop. Then, while counting the turns, turn it out until idle, once again, begins to drop. Now turn inward to the midway point between idle drops. Reset idle speed, if need be, back to 1250 rpm. You are now done fooling with the fuel screw and the idle speed - do not touch either one again. Any remaining problems are NOT due to fuel screw settings or idle speed settings.

Any remaining problems with startup (hot or cold) - if carb related - is due to a carb fault that has to be fixed via disassembly and "repair".

With the stock exhaust system in use as well as the stock CVK setup, the snorkel should NOT be removed. The stock CVK setup requires a stock airbox config in order to operate/fuel properly..

 

Thank you Sir I shall do this while waiting for my 128 main jet and N1TC needle. I shall only clean and replace the air filter and leave the rest alone. Much Appreciated

 

Use of the N1TC and a DJ128 main jet ( or a K128 main jet) on a stock exhaust and airbox is outside of my knowledge - DJ has such configurations "covered" with the 2152 kit.. The N1TC is extremely short and very aggressive.. In a stock bike, care must be taken in order to not cause overfueling..


Hot and cold starting is pilot system fueled and controlled - nothing about main jets and needles will have any affect on starting..

 

That being said is having to crack open the throttle while hot starting symptom of a pilot jet too large? Mine is a 40 and the needle has been shimmed with one star washer.

 

No.
If the problem is carb related, ( and not ignition system ) , it is a symptom of a clogged pilot jet, a faulty fuel screw / idle speed relationship, a faulty float setting.

If setting the fuel screw and idle, as I specified above, goes well, and the bike ends up idling well at 1250 rpm, you should replace your spark plug and gap the new one carefully.

Point being, if the pilot jet is partially or fully clogged, the procedure for setting the fuel screw and idle speed will fail.