Ran WR with no oil filler cap.....

Full disclosure, also posted this in ADVrider for advice.....

Ok, I'm pretty sure this is a boneheaded mistake on my part, but I either lost or never replaced the oil filler cap on my WR250R before I went on a ride today. I just changed the oil recently (Rotella T6) and most likely did not screw it on, or did not screw it on tightly enough, I don't remember. This was the first ride after the oil change, and I did 20 miles on the road and then another 3 miles of 1st/2nd gear singletrack trail riding (mostly uphill) until I realized that I had a "leak", when I dropped the bike at low speed and noticed oily residue on that side of the bike. I did notice a little residue on my muffler guard after the road ride, so it is safe to assume I had been riding without an oil filler cap the whole time. I was way out on the trail still, so I had to baby it another couple miles since the trail was too steep to push out in spots, and I was on the side of a hill so there was no bailing or getting towed out. I cut the engine on every downhill and coasted when I could, and made it to the trailhead. I then hitched a ride to my pickup and returned to retrieve the WR.

So my question to my fellow riders, whats the next steps? I'm planning on draining the oil pan to see if any oil is even left. From there, I was going to fill it up again, find a suitable cap, and then start it up to see how it is. The bike seemed fine up to the last point I ran the engine, but I didn't go above a slow 2nd gear after I noticed the issue. Or is it better for me to get the engine checked out first, since running it could damage things further and require costlier repairs? Thanks!

dartmouth01 wrote:

Full disclosure, also posted this in ADVrider for advice.....

Ok, I'm pretty sure this is a boneheaded mistake on my part, but I either lost or never replaced the oil filler cap on my WR250R before I went on a ride today.  I just changed the oil recently (Rotella T6) and most likely did not screw it on, or did not screw it on tightly enough, I don't remember.  This was the first ride after the oil change, and I did 20 miles on the road and then another 3 miles of 1st/2nd gear singletrack trail riding (mostly uphill) until I realized that I had a "leak", when I dropped the bike at low speed and noticed oily residue on that side of the bike.  I did notice a little residue on my muffler guard after the road ride, so it is safe to assume I had been riding without an oil filler cap the whole time.  I was way out on the trail still, so I had to baby it another couple miles since the trail was too steep to push out in spots, and I was on the side of a hill so there was no bailing or getting towed out.  I cut the engine on every downhill and coasted when I could, and made it to the trailhead.  I then hitched a ride to my pickup and returned to retrieve the WR.

So my question to my fellow riders, whats the next steps?  I'm planning on draining the oil pan to see if any oil is even left.  From there, I was going to fill it up again, find a suitable cap, and then start it up to see how it is.  The bike seemed fine up to the last point I ran the engine, but I didn't go above a slow 2nd gear after I noticed the issue.  Or is it better for me to get the engine checked out first, since running it could damage things further and require costlier repairs?  Thanks!

Depends on how much oil comes out I guess. I would capture and measure it to see how low you really were. If it was me and the engine was running ok at the last shut off, I'd change the oil out and start it back up again and let it idle to listen for any bad noises. I mean, you are either going to have toasted bearings or not. If they are still ok, worst case would be pre mature wear. Good luck.

I would also really look at the oil filter contents to see what dirty little secrets it's hiding.

If you think much dust and debris got in there, or water, you might want to consider flushing through with a couple back to back oil / filter swaps.

Thanks for the advice guys. Quick update, I just opened the drain plug and thankfully some oil came out. I'm still capturing it and will filter through a paper filter to see if I can find any metal, but I would say ballpark I have about 500ml of the original 1300ml I put it. I'll measure it out after I filter it. My plan is to replace the oil, run it for a few miles, and then change the oil and filter and review what may be inside either. If things look good and sound good, I'll replace oil and filter one more time and ride it until I notice a change. If I get some downtime, I'll pull off the top end cover and look around.

I feel so dumb that I almost want something to happen to punish me for my stupidity, but hopefully the gods will take kindness on me and let me dodge this bullet.......

Oh, and I got an oil filler cap from the dealer. $20 including the o-ring. I'm sure its highway robbery, but if everything goes well, it'll be the best $20 I've ever spent, except that one time in Montreal.....

My bet is youre fine. Replace oil and filter, and thats about it. You might want to do your next oilchange a bit earlier than normal, or atleast inspect the oilfilter.

My oil filler cap came off a BRAND NEW WR250F on a muddy as hell track. No idea how long it was missing.

Bike was fine. I changed oil 3 times right away. Bike purred till the day I sold it 2 years later.