Hey folks. I just recently obtained a 2001 XR400R. I traded my daughter's 2004 KX100 straight up for it since she doesn't ride the KX much anymore. Anyway, it was in pretty good shape when I got it but the gas tank was full of deteriorated petcock filter pieces that got sucked into the carb (36mm Mikuni pumper from XR's Only bought/installed by the previous owner in 2007). I cleaned the tank, removed/cleaned the carb, installed new OEM petcock, gasket, etc. The previous owner also installed a Uni air filter, removed the snorkel, and installed a Honda muffler tip (the one without the baffle/larger opening). I changed the oil with Amsoil, put in a new spark plug, and put on some new plastics and a black gripper seat cover. The bike hasn't been beaten on, trail ridden only, but the previous owner probably just rode it, power washed it, sprayed it with lube and parked it. I had to clean out the cables (clutch, throttle, compression release), remover the sub frame and cleaned/greased all bearings, axles, etc., adjusted the front/rear suspension and sag. The stock chain/sprokets are still in good condition but I still might replace them in the spring. New tires put on in August last year. It's lookin'
good now and starts on the 2nd/3rd kick every time. I'm just curious about this pumper carb deal. When exactly should that white plastic lever actually activate the A/P "pump pin?" I haven't really gotton a chance to get on it much since it's the middle of winter here in Michigan. Any advice/help on the carb woulb be appreciated. I'm an old 2 stroke guy...............Thanks