08 WR250R Idle Irregular, Heat Question

I just picked up the bike used and am wondering about the idle irregularities I have noticed. It's pretty subtle most of the time and seems to get better after the bike warms up. The bike is stock and it starts up fine, never stalls or anything. When you gas the bike it's perfectly fine, no problems with it hesitating on acceleration. Grabbing the clutch and or going through the gears does not affect the issue at all. But the idle isn't always consistent. Every so often it's like there's a small blip. Like if a heart was beating and skipped a beat but then started beating fine again. It's pretty subtle most of the time, but I just am worried about it. I don't know if the bike is idling too low or if the fuel mixture is too lean or what. It just seems to have a slight blip, then is fine for a few seconds. I'd say it idles smooth for 8-10 secs then has a really quick blip and it does seem to get better after the bike is warmed up. As far as I know it has the original spark plug, haven't checked it yet and I'd assume the air filter may be old too. Original battery, mostly everything is stock as only the sprockets have been changed. To me it seems to idle low but I don't know what is low for a WR250R. I have put my hand around parts of the exhaust and engine and they feel fine. As in I don't feel any air escaping or anything. I have listened to the engine with a piece of wood(like the screw driver trick, works great) and it seems fine. Again I am not familiar with how a WR250R should sound. Anyone have any suggestions? Also, anyone have a good video of what the engine should sound like? How noisey are these bikes? Should I hear the valves slightly tapping?

Uploaded a video. This is about the worst I've heard it. https://youtu.be/_IKdRKt37_o

Sounds just about the same as mine. I have an 08 with about 6200 miles on it. When I first got it I thought the engine was quite loud. I had an 86 Honda XL600R before this bike and it was much quieter. My buddy has had multiple new yamaha's and KTM's and said my bike is the quietest one he's heard. Nice looking bike by the way!

Thank you. Yours has the same semi inconsistent idle? You may have to listen a couple times to hear what I mean . I appreciate you responding.

I really don't hear anything abnormal.

How many miles on it?

A new plug, a freshly cleaned air filter, and a thorough check of all things "under the hood" by you might bring better piece of mind.

If nothing else, or anything, bringing the idle rpm's up a bit wouldn't hurt.

Here's mine - ignore asinine commentary please:


and with Q4:



My idle sounds a good bit faster than yours....

Indeed it does sound a good bit faster idling. Your video and others confirms my thought it's idling low. But you don't hear my engine hesitation?

What I heard sounded like the idle is in a place where it may or may not keep running depending on the conditions.

I'd bet if you increased the idle rpm's you won't hear that.

As you've stated, the bike runs fine when riding it.

I think the idle speed is your only "problem".

That's what I was thinking but being new to the bike I guess I just wanted affirmation that it seemed okay. I briefly looked for the idle screw in the dark but didn't see it. Hopefully I can get home at a decent time and see if that takes care of it. Maybe pull up the diagnostic mode I read about and see what rpm it's at. Thank you for taking the time to respond. This forum seems to have a good community and I'm glad to have a resource like it. Im planning on doing all the usual mods and am pretty excited to own the bike. I wanted a WR250R for a long time. Finally got one!

So I located the idle adjustment and played with it a bit. Increasing the idle rpms did help some but I can't get it completely gone. I had to turn the screw quite a bit for any change one way or another. Now I didn't get a chance to monitor the rpms on the speedo, this was just me listening. While I was messing with it the bike got really warm sitting still idling, the gas tank/shrouds were fairly warm to the touch and the fan kicked on. Is that normal for it to get that warm idling? It's only about 72 degrees Fahrenheit tonight, a little humid. Obviously since I wasn't moving there was no air to help cool off the engine. I took a quick spin to get some air over the bike and I could tell the temperature did drop. I checked the radiator fluid level and it seemed fine, just another thing I am worried about now not being familiar with the bike heh. If someone could comment on the heat question and the idle still being slightly off I'd appreciate it. It was warm enough that I could feel the heat radiating onto my legs. It was probably just from sitting still but I'd like some input.

I think it is normal when idling for the fan to come on. With no airflow through the rad it doesn't take that long to warm up the coolant.]

My idle is very similar to yours. I plan on looking into the CO adjustment through the dash to see if that will smooth it up.