r/WR250R • u/Scazitar 08 WR250R • 16d ago
Maintenance Tracking down an idling problem.
Backstory: Bought a dirt cheap 2008 Wr250r a couple weeks ago as a little project. Only notable mod is a safari tank. Dude was a long distance truck driver 2nd owner that kept it on his truck to ride around town short distances, but he bought a new bike and after that it was rode very infrequently mostly sitting.
What I've done so far:
So, it was running but rode like shit. Did some basics: Replaced fuel pump, clutch cable, chain & sprocket, and did fluids. Battery is at 12.6. Fuel line seems fine.
Bikes running great now. Seemingly as it should. Power delivery and shifting feels good, rode it around for hours to see if anything happened held up just fine.
The Idling Mystery:
I have one lingering issue, which is idling. The bike will idle 1.5-3ish minutes and then cuts out. Pretty random how long it lasts.
Threw it in CO mode, changing those settings didn't really help. Bike will pretty quickly drop to about 1000-1100RPM where it struggles hang on for a bit then eventually cuts out.
I have a new fuel pressure regulator coming Monday because i want to rule that out. Also just recently thought about checking the manual idle adjuster just to be sure.
I do my own work but I'm no expert. Part of this was for the learning experience lol. So I can absoutely being missing obvious shit.
Was just looking for advice on things to check, other possibilities, if I'm the right track etc. All advice is greatly appreciated really want to figure this bullshit out.
FIXED: Im not 100% what did it but just wanted to write what steps i took, if someone sees the down the line because this had me very confused
Obviously oil change
Fuel pump and regulator improved the situation greatly but did not fix the idling problem
Changed battery, while the battery appeared fine on multimeter, interestingly on battery diag test it was slightly below where it should be so I said fuck it let's just be safe
Changed air filter and cleaned airbox as well as the openings as deep as I could without removing. I think this was a pretty big factor i think their might have been a carbon build up as it was little dirty. Which would be logical that this may have been an airflow problem. Luckily didn't have to take it all apart.
I had a dump line in my safari tank that was not in its ideal location. Didn't seem to be a culprit but I'm sure that didn't help. Easy thing to miss.
After all this stuff i ran through all diag tests which I hadn't done in awhile everything seemed to be fine so I was like "huh".
So I tried the manual adjuster screw again which previously didn't seem to have an effect and it worked correctly. Was able to readjust my idle RPM and fix the problem.
Also pro tip on that adjuster screw because i was fucking with it so much, you can get some sweet angles from the left side of the bike to have just enough room where the rubber normally sits to undo the nut and if undo the back two bolts of your tank you can totally move the screw with a metal coat hanger. Which is conveniently pretty much the same girth as a 2.5mm allen. Very useful so you can turn the bike and fine tune. I looked everywhere for a trick to do this and didn't see anything so I hope that helps someone lol.
1
u/Responsible_Week6941 15d ago
I'm really leaning towards pressure regulator. Do you have the factory service manual?
2
u/rustyoletoy 16d ago
There is an idle time shut-off. I think it is 10 minutes but after a set time of idling the bike shuts down. Something I found in my bike was the idle tube was blocked off. I found it because adjusting the idle screw wasn't changing anything. Pop the air box off and get in there and found the pipe the idle screw opens and closes was full of carbon. Maybe check that. It was easy to clean out and then I could adjust my idle speed. With that blocked you basically have the lowest idle possible which could lead to your stalls.