WR 400 High Revvin' at idle???

I was riding on a track Sunday that had a long flat straight that I could full tilt for almost a minute. There was a tight turn at the end and on about my 5th lap not much happened when I rolled off the gas. The engine was revving like it was stuck at 1/4 throttle. The throttle felt normal, no slack in the cables, and after I shut the bike off it sounded like the slide was snapping shut like normal. This has never happened before and it was a bee-yatch trying to get it going again, and I had to constantly blip the kill button on the ride home to get through the tight stuff. I took the air filter out when I got home, everything looked fine, and started the bike without the filter, same thing. I haven't popped the carb yet but was wondering if anyone else has run into this. :)

Good luck finding the problem...but first thing check for a frayed cable INSIDE the lower cable where it mounts to the carb

Thanks. It may be the lean thing, I just put a White bros pipe on. Funny though, it worked fine for a couple of days with the new pipe. I'll open the tap a bit and check the cables too.

do check you carb slide. (the parts manual call it the valve pin) it might have cracked. try not to start your engine again till you have pulled your carbie apart cos if its really cracked, you run the risk of getting the broken pieces of the slide sucked into your cylinder.

good luck!

Bingo, right on the money boys, it was the carb slide plate. I thought I read that some were plastic but mine is definitely metal, and thicker than I'd like to have injected into my cylinder. Looks like 1 big piece. Thanks Troy for telling me not to start it :D :D. There is a crack up the side and another piece was fixin' to break off. I was WFO when it broke so hopefully there was enough velocity to blow it through clean without tagging a valve or cylinder wall on the way. This is a great site, that's the last thing I would have looked for.


The bad news is that it'll probably be a month before the new piece lands here. I broke my rear shock and the bike was down for 2 months waiting for the replacement. The carb plate broke on my second run. I barely blew the cobwebs off. :usa:




Troy, I did a search and see that you may have tougher slides available? Any left?

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