My cousin just picked up a 03 baja that was over stock. The quad has a bad mis and stumbles all over its self from 4200-5500 and then after 5500 it runs fine? Do you guys think this is electric or carb related? We pulled the carb and cleaned it and found nothing wrong. We checked the battery and charging system and everyting was fine. Any help is appreciated. It seems like the problem is worse when the engine is up to temp.

 

what clip was the needle on and what main jet is in it. Also what altitude???

 

I didn't note the needle position or jet size we didn't change anything So it is at the stock speciifications. I will see if he pulled the carb. i am located near Chicago so i think it is 780 above see level.

 

stock is 165 main and 2nd or 3rd clip from the top.(can't remember for sure) If all is stock at that altitude I think it runs better at 4th position from the top on needle. Make sure the needle is properly positioned in the slide and the spacers are in the correct spots. If ya really want it to rip for not much cash put the mr. horsepower end cap on and then put the clip on the bottom spot with the same jet. Leave the stock filter in for this. K&N 's do not help. I bought one before finding that out [img]i/expressions/face-icon-small-disgusted.gif[/img]

 

Reading your initial post it looks like the bike was used when ya got it and whoever owned it first might have messed it up.

 

mr hp recomends a 175 main at sea level if you run his end cap, at 780' i'd say thats close enough to sea level. If you have a k&n put it on, after one pass it will start to shine over the stock. Also put your needle in the fourth position. Check you air screw, start with it at about 2 1/2 turns out, then keep adjusting out till you get your highest idle. readjust you idle back to where you want it, that should get you close enough to tell if its carb related.

 

I was told by hp research that the k&n did not help increase hp at all. ??? I was also told to keep the stock jet and move the needle to the richest position. The 165 main stock mikuni is the same as a 175 dynoject or close to it. These are coming from hp research as of one month ago. Hp research does have a toil filter or something that sounds like that, it works better than the factory and is cleanable.