3 replies to this topic
Posted June 11, 2009 - 12:38 PM
Picked up a 2003 WR450F yesterday for my Dad. The previous owner put an Edelbrock on it, pretty impressive carb, wish I had one on my XR. I looked around, but didn't see much in the way of tuning this carb, I have a couple extra needles for it, not sure what is in it or how many clicks/what position it's set at right now. I was wondering if someone could give me a starting point to tune from. The bike has an FMF pipe, and my elevation is 4500, running up to 8k or so (I believe the bike was set up for < 1000ft.) If someone could give me a starting point (Needle and position) for this altitude, I'd appreciate it.
Posted June 14, 2009 - 07:20 PM
Worked on the carb some today. For the starting point, the bike has an FMF pipe, and wasn't uncorked, and I'm at 4500 ft.. I removed the snorkel, cleaned the air filter, and rode it a bit to determine where it was at. Low end power was great, stumble at the high end. Brought it home, pulled the carb, went from needle 7 down to 6 to lean it out. Put it back together, high end stumble gone, bottom end not quite right. For these carbs, the mid to high changes are done by needle swap, low to mid are clicks up/down. I leaned it down via the manual clicky on the top of the carb, very handy adjustment since you don't have to take the carb out for this. About 6 clicks later, runs like it's on fire. Seems like the new needle causes just a bit of mis-alignment in the slide, I noticed when I put it together it wasn't quite as smooth. Really doesn't affect it while riding. Didn't adjust the shot circuit, the take off is enough to dump me off the back if I'm not paying attention already.