Just picked up an XR400 (Please Read - Help)

[ERIC ANDERSON]

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

[Rediron]

http://www.mikuni.com/pdf/hs40_manual.pdf

I just ordered a pumper myself so I can't answer your question yet, but check out this link on tuning the mikuni, it should be helpfull

[Trailryder42]

The Mikunis off idle response is pretty good "without" injecting more fuel into it with the pump. With mine, I've found that when the pump is set to come on right off idle, it's too much, too rich for that throttle position and it coughs and stumbles. I turn the pump come on screw all the way in, seating the spring. That has the pump come on about 1/8 or so throttle. Just about right in my experience and it's what I recommend to everyone that asks.

So that makes the gap between the white pump actuator arm and the pump rod about, maybe 1/4"?

Good looking bike. I bet you enjoy it. While it's winter, take out and lube the swingarm bolt too. Being a used bike, that's one major thing you want to be on top of and know the condition of from the start.

[scott_01_xr400]

where in Michigan are you ?

[ERIC ANDERSON]

Thanks for the replies guys. I checked out that one link and it seems that it explains the position of lever for the Harley. I have read that the lever should be approx 1/4" above the A/P and I've read that the screw should be turned all the way in. With the screw all the way in, the lever doesn't contact the A/P until better than 1/2 throttle. Oh yeah, I also noticed that the "spray" from the A/P was hitting the left side of the carb. I adjusted that so the spray now sprays directly at the needle. I guess I'll have to play around with it once the weather breaks and find the optimum position for it??

scott-01-xr400 ---- I'm in Whitmore Lake. Just 2 miles east of US 23 and a mile north of North Territorial (Washtenaw Co.) if you're familiar with the area. Thanks again.

Eric

[z50nichols]

nice bike! I'd love to trade my wifes crf150 for a bike like that. We sure got alot of snow up here in kalkaska michigan,

[ERIC ANDERSON]

nice bike! I'd love to trade my wifes crf150 for a bike like that. We sure got alot of snow up here in kalkaska michigan,

Thanks. Can't wait until spring gets here so I can get on it a bit and see how it does. I thought it was a pretty good swap for a KX100. The motor purrs like a kitten and the trans/clutch work perfectly too. The bike was pretty much babied, the previous just never did much to it but oil changes and tires. There wasn't even a speck of dirt in the air box. We got a couple inches of snow over night and the possibility of 4"-8" Friday night into Saturday morning. I don't think it's forecasted to make it as far north where you are though.

[justcountry]

The bike looks great, How much do you think your trade was worth? Im looking at an 04 right now that looks really clean for 2000$

[ERIC ANDERSON]

The bike looks great, How much do you think your trade was worth? Im looking at an 04 right now that looks really clean for 2000$

I'm not too sure. the Kx was super clean. I had to do a little TLC on the XR. Kelly Blue Book on the Kx was $1650 and on the XR was $2150, or something close to that. But I think I got the better end of the deal...........

[aj440]

nice bike, sounds like a good deal to

[mike_o]

Eric,

good choice! I own an ´00 XR400 with a Mikuni TM36. I also find the set-up to work best with a little free-play. I'm not sure how much in terms of 1/4s or 1/8s, but I have app 2mm of play w throttle off. Maybe 1/16?

I'm looking forward to spring as well - I'm joning a bunch of friends for a trip to Poland, where theres still plenty of open areas. Pic from a trip 4 years ago.

best regards

Mike