Ibrokeit

With a more free flowing exhaust the stock jets should be giving you a lean burn not rich. So with that I would rule out all other causes before you go pulling the carb. a dozen times. The first things you should ALWAYS do is check your basics, Are the valves adjusted right, Is the air filter clean and unobstructed (a mouse nest up in the snorkel tube?) How is the compression? Also the diaphram on the slide could have a pin hole. A sticky choke cable or non-seating enrichment valve will also get you chasing your tail. One more thing would be to inspect the packing in the exhaust to see that it is not saturated with fuel/oil or something else that may be cause more back pressure.

One thing to watch out for on a used machine is you can't go by what number size jet is in it now, If some gorilla used a torch tip cleaner to clean that jet in the last 22 years its way over jetted now. sometimes just getting a new jet that is actually what it says it is will cure the problem. Proper jetting takes patience and some trial and error. Each machine is different so even the pros are just guessing, Educated guesses but still a guess for the most part. Internet mechanicin is easy,....If I screw up I just log off, Fine tuning is most definitely "Hands On":biggrin:

I am new on here so I don't know about how most ride so I don't know if you ride your 400 very hard or not. Brake pads for most every vehicle made now come in different types of material, Some are harder (racing compounds) and meant to be used harder, They don't work as well till they get some heat in them. So if you don't usually get a lot of heat in your brakes they may not work as well for you as stock type pads would. If you get brake fade (overheated pads) you might be a good candidate for racing pads. No matter what style you use I always suggest googleing "bedding brake pads" for techniques on seating the pads or shoes into the mating surface.:coolgleamAc:

Cali. desert rat learning that real trees are a lot like the ones on H.R. PuffnStuff. They just reach out and grab you!!:shock2::shock2: Hoping by spring we will have some good tracks worn in before ole Mother Nature gets all roided out and turns the trails into jungle,....AGAIN!:aargh: The wife is already in here but I guess she didn't want me to know:confused: But just the little I've read it seams like a cool site. Can't wait till the shooting:shoot::shoot: slows down enough to start ripping it up again:yes: Might just put on paddles and dune it till bambi says it's safe to go back in the woods :drivingc: