fast idle

Last weekend I was doing a short ride and in the middle of it I noticed that it was idleing faster then usual. It has since stayed that way! What is wrong? Is my FMF programmer going bad or what? It runs fine other then that. Berwyn Also I have two wr owners in group now for a total 4. All are wr250Rs, no X's yet.

Weird? I doubt it would be the fuel controller, if it went crazy it would make the bike lean or rich which would not increase idle speed unless it was way off in the first place and the controller screwed up and improved the mixture, probably a rare occurrence
The bike has an ISC to control idle speed, I have never seen one stick but I guess it could happen
This is adjusted by the ECU so if it were my bike I would go through all the connectors and blow them out and put some dielectric in them, for instance if the ecu were to read in incorrect idle speed due to bad connection it could attempt to increase idle speed
It also has a slightly increased idle speed for warm up mode, again could be a weird connection issue

might check for vacuum leaks

Thanks guys for getting back, have not looked at it yet but will later tomarrow. Will post what I find, Berwyn

I found the cause for the fast idle, sure enough it was an vacuum leak ! Where I had removed a vac line from the top of the throttle body that goes to the small vac tank under the seat and plugged it, some how the plug got off the fitting. So after putting another plug on, reinstalling the tank it now idles like it should. Seems one thinks of worst possible thing when something starts to go wrong, thanks to all for your ideas. By the way we now have 5 wr,s with at least 3 doing the western half of the TAT togather this Sept. Berwyn

pardon for resurrecting this thread, but sounds similar to what im having now on my wr250x

i had just replaced the spark plug and rode around for a day. the following day, i went out and practice some wheelies and after about 1/2 hour, i noticed the idle being high.

ive got videos with sound of pre-high idle:




and the new high idle:



could this be the same as the vacuum leak described by Berwyn?

any and all help is appreciated! thx

Have you removed AIS and Flapper junk?

If so - yes - you could have the same issue.

Have you checked around for things that were once plugged and now might not be?

ive only had the flapper removed this entire time. AIS is in tact, but never had the fast idle issue.

when i removed the flapper, i also capped the plug on the throttle body.

i'll double check when i get the tank & seat off.

thx.

I have noticed on my bike that when the air cleaner is dirty it bumps the revs up to 1000rpm more at idle.

yep, just like berwyn i was missing the plug/cap to that line on the throttle body.

replaced it with a spare, and now she's idling as normal.

thanks all!

Hey just wondering if both y’all who had issues were running aftermarket exhaust and that was part of the issue. I have a full stock exhaust system and encountered the same issue. I think it’s vacuum as well and thought it was that even before finding this thread. I’ve ran it without the Baffle and air filter and nothing has changed still idling about 1-2k rpms to high, from the cold start all the way up until it’s warm. Also looked for boot leaks or vacuum line leaks throughout but even with all the plastics and everything off it’s hard to get to or feel around for cracks or air suction. Going to try the Ether trick next. But just curious if it could be the same issue or is it something hthat happens after y’all did your Aftermarket kits and eliminated the re-emissions B.S.?