NGPZ - More t'shootin' ...bike dies after highway run

[Steven Bixby]

Well, another odd thing going on.  My wife's Ninja 250 quits when she
comes off a freeway (after typical 70-80 mph run for at least several
minutes).  When she exits and comes to a light or whatever, clutches
in and poof, bike quits.

It started happening just a couple days ago and usually started right
up, but today she messaged me and said it took a bit longer to
restart, only she was in a toll lane for the (San Francisco) Bay
Bridge - a horrible place to stall out.

Any suggestions for what could cause this?

I don't think it's over-cooling; it's liquid cooled and I think it
runs warm enough that the t'stat is wide open after it warms up
anyway, but I could be wrong.   I'm thinking it's some other issue.

Things I know that are potential existing problems:

Battery is on it's last legs; it starts and charges OK I believe, but
the battery capacity is getting pretty low.  I have a new battery
waiting at the shop now.

Head-cover leaking - there's a bit of oil in the spark-plug holes and
around the cylinder head cover - I have gaskets on the way for the
next valve-adjustment opportunity, but could oil in the wells cause
something like this?  (I'm thinking "probably not".)


By the way, regarding the slow-to-idle issue - I didn't work on range
bikes this week, so i wasn't able to try the vacuum check tricks.
Next week probably.