Going from fcr1 to fcr2 on wr400

yes u gotta remove the hex screw on top of the slide to get the needle out..

try n bring up the clip, 1 notch n c how it goes.. gd luck..

I wouldn't worry so much about deceleration popping. You aren't making any power when you're decelerating anyway.

But if it's really bad like loud cracking and popping, you may have a loose connection somewhere in the exhaust train. Check for air leaks at the cylinder head/headpipe connection and around the pipe/muffler connection. This has solved some of my bike's popping issues in the past.

Also, to answer your pilot screw-pilot jet question: If the bike runs better with the pilot screw all the way in, you need to try the next smaller pilot jet. If you have to turn the screw out more than about 3 turns and it keeps running better, go to the next larger pilot jet size.

If you have the proper pilot jet in the bike, you can adjust the pilot screw at a fast idle. Get the bike warmed up and leave it running. Then adjust the idle speed to a medium-high idle. Now turn the pilot (fuel) screw in until the revs start to drop off. Then turn the same screw out until the idle speed begins to drop off. The proper screw setting is halfway between those two extremes.

If the idle speed just continues to increase when you turn it all the way in, then you need to get a smaller pilot jet and try the exercise again. If the idle speed increases as you keep turning the screw way out, then try the next larger size jet and test the screw position again with the new jet.

In other words, don't set your carburetor solely based on whether or not it pops after you let the throttle out.


Can you use a handlebar mounted hot start on a WR426 2001 ??

I think there is an aftermarket handlebar mounted hot start that works with the carb on the '01 WR. Maybe Zip-Ty but I'm not sure.

i've got a zip ty handlebar mounted hotstart on my fcr1.

thanks rich. i don't think the popping is due to an exhaust leak because it only started when i changed to the cnc slide. ie no popping w/ the stock slide. although i did have the header off last week when i took off my head to remove the broken slide piece, so it's worth checking

it runs best AND has the most popping with the fuel screw most the way in. backing it out makes it stop popping, but it starts bogging out down low/surging up high, and just running like dog piss in general. so i'm guessing the last thing i want is a bigger pilot. sooooooo, i could just put it where it feels/pulls good and deal with the popping except that i ride it around the neighborhood and it's really obnoxious. i put the clip down one knotch to richen it up after quite a bit of work pulling and reinstalling the carb, and to be honest didn't feel any difference.

you're right though, it sounds just like the popping you get with an exhaust leak. i know my packing is ok. any tips on checking for exhaust leaks? just feel with your hand? i remember something about spraying wd40 near the manifold, although my guess is it would be more an exhaust issue.

fuel screw: i was told to turn it to it idles the highest, then back it off half a turn. seems to work pretty well.

The way I have checked for exhaust leaks is to feel for puffs of air with your hand. There won't be much of a question, you either feel it or you don't. If you spray WD40 on your exhaust, it will definitly smoke a lot and it just might start a fire. I think the place you should focus on is the head-pipe connection. If the pipe is cocked just a little, it won't make a perfect seal.

one of the header bolts backed out. duh, i feel dumb. it's just that it happened at the same time that i changed the slide.

anyway, the jetting aint perfect, but it's good enough for now. ie i'm sick of dealing with it. for the most part she runs great, thanks for the help all.

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