Hey guys, wanted to post a quick experience and get some opinions on what happened / where I need to go from here.
I was riding at 65 in 5th (very close to top speed, most likely WOT) when the bike started lurching and surging, almost like fuel starvation (still had 1/4 of a tank). I pulled the clutch and it sputtered for a bit and died. Could not get it to restart at all! I checked the oil level, and it was just a couple MM below the low limit
. I left it, then went back to it ~4 hours later, added some oil to get it in spec, and attempted start-- no go. It would just turn over endlessly, never catching at all.
So, I trailerd it home. Let it sit for a few days while I was camping, then started work on it. First of all, with a tiny bit of coaxing and choke, it started. Ran rough for a couple seconds, but once it warmed it was idling and riding OK. Took it around the block a couple times, no issues at all that I could feel. I rode it on a long straight road and at WOT in 5th, it started sputtering and lurch/surging again. I pulled clutch and kept it alive with a little throttle while I slowed down, and it never died. Idled fine after that. I ran this test again, and it seemed to start acting funny around 30-45 seconds at top speed/gear. Of note, in 3rd/4th WOT, I didn't seem to have any problems; however, because of the high RPMs in those gears I didn't run it like that for as long as I did in 5th.
I noticed a small oil leak, but couldn't exactly tell where it was coming from. No oil on the ground, only on the fins and lower engine. I cleaned up the cases a bit, so hopefully I'll be able to determine the leak location soon. I may even have multiple leaks, as there were a couple areas that seemed suspect; namely the head gasket, right side case, and possibly around the head bolt near the spark plug.
I didn't ride it to work this morning for fear that the issue would rear it's ugly head again. It's been 974 miles since the last oil change, so I guess I might do that. I'm also feeling like I'm going to need to replace the clutch plates soon, as it slips occasionally. Finally, I'll take a look at the airbox to make sure it's OK, and maybe run some seafoam through the carb.
Any other thoughts or suggestions? Thanks in advance!
Edit: Bike has very near 10,000 miles on it. It's had some other issues too involving the flywheel and backed out bolts, but I think that's unrelated here.